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The requirements for spacing, location, and position of sprinklers shall be based on the following principles:
  1. Sprinklers shall be installed throughout the premises.
  2. Sprinklers shall be located so as not to exceed the maximum protection area per sprinkler.
  3. *Sprinklers shall be positioned and located so as to provide satisfactory performance with respect to activation time and distribution.
  4. Sprinklers shall be permitted to be omitted from areas specifically allowed by this standard.
  5. When sprinklers are specifically tested and test results demonstrate that deviations from clearance requirements to structural members do not impair the ability of the sprinkler to control or suppress a fire, their positioning and locating in accordance with the test results shall be permitted.
  6. Clearance between sprinklers and ceilings exceeding the maximums specified in this standard shall be permitted, provided that tests or calculations demonstrate comparable sensitivity and performance of the sprinklers to those installed in conformance with these sections.
  7. Furniture, such as portable wardrobe units, cabinets, trophy cases, and similar features not intended for occupancy, does not require sprinklers to be installed in them. This type of feature shall be permitted to be attached to the finished structure.
  8. *Sprinklers shall not be required to be installed within electrical equipment, mechanical equipment, or air handling units not intended for occupancy.
System valves and gauges shall be accessible for operation, inspection, tests, and maintenance.
The maximum floor area on any one floor to be protected by sprinklers supplied by any one sprinkler system riser or combined system riser shall be as follows:
  1. Light hazard — 52,000 ft2 (4830 m2)
  2. Ordinary hazard — 52,000 ft2 (4830 m2)
  3. *Extra hazard — Hydraulically calculated — 40,000 ft2 (3720 m2)
  4. Storage — High-piled storage (as defined in 3.9.1.16) and storage covered by other NFPA standards — 40,000 ft2 (3720 m2)
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The floor area occupied by mezzanines shall not be included in the area limits of 8.2.1.
Where single systems protect extra hazard, high-piled storage, or storage covered by other NFPA standards, and ordinary or light hazard areas, the extra hazard or storage area coverage shall not exceed the floor area specified for that hazard and the total area coverage shall not exceed 52,000 ft2 (4830 m2).
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Multistory buildings exceeding two stories in height shall be provided with a floor control valve, check valve, main drain valve, and flow switch for isolation, control, and annunciation of water flow for each individual floor level.
The floor control valve, check valve, main drain valve, and flow switch required by 8.2.4.1 shall not be required where sprinklers on the top level of a multistory building are supplied by piping on the floor below.
The floor control valve, check valve, main drain valve, and flow switch required by 8.2.4.1 shall not be required where the total area of all floors combined does not exceed the system protection area limitations of 8.2.1.
The requirements of 8.2.4 shall not apply to dry systems in parking garages.
Multiple buildings attached by canopies, covered breezeways, common roofs, or a common wall(s) shall be permitted to be supplied by a single fire sprinkler riser.
The maximum system size shall comply with 8.2.1.
Unless the requirements of 8.2.6.2 apply, detached buildings, regardless of separation distance, that do not meet the criteria of 8.2.5 shall be provided with separate fire sprinkler systems.
When acceptable to the authority having jurisdiction, detached structures shall be permitted to be supplied by the fire sprinkler system of an adjacent building.
Sprinklers shall be installed in accordance with their listing.
The requirements of 8.3.1.1 shall not apply where construction features or other special situations require unusual water distribution, and listed sprinklers shall be permitted to be installed in positions other than anticipated by their listing to achieve specific results.
Upright sprinklers shall be installed with the frame arms parallel to the branch line, unless specifically listed for other orientation.
Where solvent cement is used as the pipe and fittings bonding agent, sprinklers shall not be installed in the fittings prior to the fittings being cemented in place.
Protective caps and straps shall be removed using means that are in accordance with the manufacturer's installation instructions.
Protective caps and straps shall be removed from all sprinklers prior to the time when the sprinkler system is placed in service.
Protective caps and straps on all upright sprinklers or on any sprinklers installed more than 10 ft (3.0 m) above the floor shall be permitted to be removed from sprinklers immediately following their installation.
Unless the requirements of 8.3.2.2, 8.3.2.3, 8.3.2.4, or 8.3.2.5 are met, ordinary- and intermediate-temperature sprinklers shall be used throughout buildings.
Where maximum ceiling temperatures exceed 100°F (38°C), sprinklers with temperature ratings in accordance with the maximum ceiling temperatures of Table 6.2.5.1 shall be used.
High-temperature sprinklers shall be permitted to be used throughout ordinary and extra hazard occupancies, storage occupancies, and as allowed in this standard and other NFPA codes and standards.
Sprinklers of intermediate- and high-temperature classifications shall be installed in specific locations as required by 8.3.2.5.
The following practices shall be observed to provide sprinklers of other than ordinary-temperature classification unless other temperatures are determined or unless high-temperature sprinklers are used throughout, and temperature selection shall be in accordance with Table 8.3.2.5(a), Table 8.3.2.5(b), Table 8.3.2.5(c), and Figure 8.3.2.5:
  1. *Sprinklers in the high-temperature zone shall be of the high-temperature classification, and sprinklers in the intermediate-temperature zone shall be of the intermediate-temperature classification.
  2. Sprinklers located within 12 in. (300 mm) to one side or 30 in. (750 mm) above an uncovered steam main, heating coil, or radiator shall be of the intermediate-temperature classification.
  3. Sprinklers within 7 ft (2.1 m) of a low-pressure blowoff valve that discharges free in a large room shall be of the high-temperature classification.
  4. Sprinklers under glass or plastic skylights exposed to the direct rays of the sun shall be of the intermediate-temperature classification.
  5. Sprinklers in an unventilated, concealed space, under an uninsulated roof, or in an unventilated attic shall be of the intermediate-temperature classification.
  6. Sprinklers in unventilated show windows having high-powered electric lights near the ceiling shall be of the intermediate-temperature classification.
  7. Sprinklers protecting commercial-type cooking equipment and ventilation systems shall be of the high- or extra high-temperature classification as determined by use of a temperature-measuring device. (See 7.9.6.)
  8. Sprinklers protecting residential areas installed near specific heat sources identified in Table 8.3.2.5(c) shall be installed in accordance with Table 8.3.2.5(c).
  9. Ordinary-temperature sprinklers located adjacent to a heating duct that discharges air that is less than 100°F (38°C) are not required to be separated in accordance with Table 8.3.2.5(a).
  10. Sprinklers in walk-in type coolers and freezers with automatic defrosting shall be of the intermediate-temperature classification or higher.
Table 8.3.2.5(a) Temperature Ratings of Sprinklers Based on Distance from Heat Sources
Type of Heat Condition Ordinary-Temperature Rating Intermediate-Temperature Rating High-Temperature Rating
(1) Heating ducts
(a) Above More than 2 ft 6 in. (750 mm) 2 ft 6 in. or less (750 mm)
(b) Side and below More than 1 ft 0 in. (300 mm) 1 ft 0 in. or less (300 mm)
(c) Diffuser Any distance except as shown under Intermediate-Temperature Rating column Downward discharge: Cylinder with 1 ft 0 in. (300 mm) radius from edge extending 1 ft 0 in. below and 2 ft 6 in. (750 mm) above
Horizontal discharge:
Semicylinder or cylinder with 2 ft 6 in. (750 mm) radius in direction of flow extending 1 ft 0 in. (300 mm) below and 2 ft 6 in. (750 mm) above
(2) Unit heater
(a) Horizontal discharge Discharge side: 7 ft 0 in. (2.1 m) to 20 ft 0 in. (6.1 m) radius pie-shaped cylinder (see Figure 8.3.2.5) extending 7 ft 0 in. (2.1 m) above and 2 ft 0 (600 mm) in. below heater; also 7 ft 0 in. (2.1 m) radius cylinder more than 7 ft 0 in. (2.1 m) above unit heater 7 ft 0 in. (2.1 m) radius cylinder extending 7 ft 0 (2.1 m) in. above and 2 ft 0 (600 mm) in. below unit heater
(b) Vertical downward discharge (for sprinklers below unit heater, see Figure 8.3.2.5) 7 ft 0 in. (2.1 m) radius cylinder extending upward from an elevation 7 ft 0 in. (2.1 m) above unit heater 7 ft 0 in. (2.1 m) radius cylinder extending from the top of the unit heater to an elevation 7 ft 0 in. (2.1 m) above unit heater
(3) Steam mains (uncovered)
(a) Above More than 2 ft 6 in. (750 mm) 2 ft 6 in. or less (750 mm)
(b) Side and below More than 1 ft 0 in. (300 mm) 1 ft 0 in. or less (300 mm)
(c) Blowoff valve More than 7 ft 0 in. (2.1 m) 7 ft 0 in. or less (2.1 m)
Table 8.3.2.5(b) Temperature Ratings of Sprinklers in Specified Locations
Location Ordinary-Temperature Rating Intermediate-Temperature Rating High-Temperature Rating
Skylights Glass or plastic
Attics Do not use Ventilated or unventilated
Peaked roof: metal or thin boards, concealed or not concealed, insulated or uninsulated Ventilated Unventilated
Flat roof: metal, not concealed Ventilated or unventilated Note: For uninsulated roof, climate and insulated or uninsulated occupancy can necessitate intermediate sprinklers. Check on job
Flat roof: metal, concealed, insulated or uninsulated Ventilated Unventilated
Show windows Ventilated Unventilated
Note: A check of job condition by means of thermometers might be necessary.
Table 8.3.2.5(c) Temperature Ratings of Sprinklers in Specified Residential Areas
Heat Source Minimum Distance from Edge of Source to Ordinary-Temperature Sprinkler Minimum Distance from Edge of Source to Intermediate-Temperature Sprinkler
in. mm in. mm
Side of open or recessed fireplace 36 915 12 300
Front of recessed fireplace 60 1525 36 915
Coal- or wood-burning stove 42 1070 12 305
Kitchen range 18 460 9 230
Wall oven 18 460 9 230
Hot air flues 18 460 9 230
Uninsulated heat ducts 18 460 9 230
Uninsulated hot water pipes 12 305 6 155
Side of ceiling- or wall-mounted hot air diffusers 24 610 12 305
Front of wall-mounted hot air diffusers 36 915 18 460
Hot water heater or furnace 6 155 3 75
Light fixture:
0 W-250 W
6 155 3 75
250 W-499 W 12 305 6 155
FIGURE 8.3.2.5 High-Temperature and Intermediate-Temperature Zones at Unit Heaters.
In case of occupancy change involving temperature change, the sprinklers shall be changed accordingly.
The minimum temperature rating of ceiling sprinklers in general storage, rack storage, rubber tire storage, roll paper storage, and baled cotton storage applications shall be 150°F (66°C).
Sprinklers in light hazard occupancies shall be one of the following:
  1. Quick-response type as defined in 3.6.4.8
  2. Residential sprinklers in accordance with the requirements of 8.4.5
  3. Quick response CMSA sprinklers
  4. ESFR sprinklers
  5. Standard-response sprinklers used for modifications or additions to existing light hazard systems equipped with standard-response sprinklers
  6. Standard-response sprinklers used where individual standard-response sprinklers are replaced in existing light hazard systems
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Where quick-response sprinklers are installed, all sprinklers within a compartment shall be quick-response unless otherwise permitted in 8.3.3.3, 8.3.3.4, or 8.3.3.5.
Where there are no listed quick-response sprinklers in the temperature range required, standard-response sprinklers shall be permitted to be used.
The provisions of 8.3.3.2 shall not apply to in-rack sprinklers.
Where a sprinkler carries a listing for both standard-response protection and quick-response protection at different coverage areas, that sprinkler shall be permitted to be installed within a compartment at the spacing for both the quick-response and standard-response listings without any separation between the areas so covered.
When existing light hazard systems are converted to use quick-response or residential sprinklers, all sprinklers in a compartment shall be changed.
Sprinklers shall have a minimum nominal K-factor of 5.6 (80) unless otherwise permitted by 8.3.4.
For light hazard occupancies not requiring as much water as is discharged by a sprinkler with a nominal K-factor of K-5.6 (80) operating at 7 psi (0.5 bar), sprinklers having a smaller orifice shall be permitted, subject to the following restrictions:
  1. The system shall be hydraulically calculated.
  2. Sprinklers with nominal K-factors of less than K-5.6 (80) shall be installed only in wet pipe sprinkler systems or in accordance with the limitations of 8.3.4.3 or 8.3.4.4.
  3. A listed strainer shall be provided on the supply side of sprinklers with nominal K-factors of less than K-2.8 (40).
Sprinklers with nominal K-factors of less than K-5.6 (80) shall be permitted to be installed in conformance with 11.3.2 for protection against exposure fires.
Sprinklers with nominal K-factors of K-4.2 (57) shall be permitted to be installed on dry pipe and preaction systems protecting light hazard occupancies where piping is corrosion resistant or internally galvanized.
Sprinklers having a K-factor exceeding K-5.6 (80) and having 1/2 in. (15 mm) National Pipe Thread (NPT) shall not be installed in new sprinkler systems.
Sprinklers shall be selected for use as indicated in this section and shall be positioned and spaced as described in Section 8.5.
Upright and pendent spray sprinklers shall be permitted in all occupancy hazard classifications and building construction types unless the requirements of 8.15.1.6 apply.
Quick-response sprinklers shall not be permitted for use in extra hazard occupancies under the density/area design method.
Sidewall sprinklers shall only be installed as follows:
  1. Light hazard occupancies with smooth, horizontal or sloped, flat ceilings
  2. Ordinary hazard occupancies with smooth, flat ceilings where specifically listed for such use
  3. To protect areas below overhead doors
Extended coverage sprinklers shall only be installed as follows:
  1. In unobstructed construction consisting of flat, smooth ceilings with a slope not exceeding a pitch of 1 in 6 (a rise of 2 units in a run of 12 units, a roof slope of 16.7 percent)
  2. In unobstructed or noncombustible obstructed construction, where specifically listed for such use
  3. Within trusses or bar joists having web members not greater than 1 in. (25 mm) maximum dimension or where trusses are spaced greater than 71/2 ft (2.3 m) on center and where the ceiling slope does not exceed a pitch of 1 in 6 (a rise of 2 units in a run of 12 units, a roof slope of 16.7 percent)
  4. Extended coverage upright and pendent sprinklers installed under smooth, flat ceilings that have slopes not exceeding a pitch of 1 in 3 (a rise of 4 units in a run of 12 units, a roof slope of 33.3 percent), where specifically listed for such use
  5. Extended coverage sidewall sprinklers installed in accordance with 8.9.4.2.2 in slopes exceeding a ceiling pitch of 2 in 12
  6. In each bay of obstructed construction consisting of solid structural members that extend below the deflector of the sprinkler
  7. Extended coverage sprinklers installed to protect areas below a single overhead door(s)
Open sprinklers shall be permitted to be used in deluge systems to protect special hazards or exposures or in other special locations.
Open sprinklers shall be installed in accordance with all applicable requirements of this standard for their automatic counterpart.
Residential sprinklers shall be permitted in dwelling units and their adjoining corridors, provided they are installed in conformance with their listing.
Residential sprinklers shall be used only in wet systems unless specifically listed for use in dry systems or preaction systems.
Where residential sprinklers are installed in a compartment as defined in 3.3.6, all sprinklers within the compartment shall be residential sprinklers.
ESFR sprinklers shall be used only in wet pipe systems unless specifically listed for use in dry systems.
ESFR sprinklers shall be installed only in buildings where roof or ceiling slope above the sprinklers does not exceed a pitch of 2 in 12 (a rise of 2 units in a run of 12 units, a roof slope of 16.7 percent).
ESFR sprinklers shall be permitted for use in buildings with unobstructed and noncombustible obstructed construction.
Where depths of the solid structural members (beams, stem, and so forth) exceed 12 in. (300 mm), ESFR sprinklers shall be installed in each channel formed by the solid structural members.
Minimum sprinkler spacing and area of coverage shall comply with the requirements of 8.12.2 and 8.12.3.
Where ESFR sprinkler systems are installed adjacent to sprinkler systems with standard-response sprinklers, a draft curtain of noncombustible construction and at least 2 ft (600 mm) in depth shall be required to separate the two areas.
A clear aisle of at least 4 ft (1.2 m) centered below the draft curtain shall be maintained for separation.
Sprinkler temperature ratings for ESFR sprinklers shall be ordinary unless 8.3.2 requires intermediate- or high-temperature ratings.
ESFR sprinklers designed to meet any criteria in Chapter 12 through Chapter 20 shall be permitted to protect light and ordinary hazard occupancies.
CMSA sprinklers shall be permitted to be used in wet, dry, or preaction systems and shall be installed in accordance with their listing.
Unless the requirements of 8.4.7.2.2, 8.4.7.2.3, or 8.4.7.2.4 are met, sprinkler temperature ratings shall be the same as those indicated in Table 8.3.2.5(a) and Table 8.3.2.5(b) or those used in large-scale fire testing to determine the protection requirements for the hazard involved.
Sprinklers of intermediate- and high-temperature ratings shall be installed in specific locations as required by 8.3.2.
In storage occupancies, ordinary, intermediate, or high temperature-rated sprinklers shall be used for wet pipe systems.
In storage occupancies, high temperature-rated sprinklers shall be used for dry pipe systems.
Quick-response CMSA sprinklers designed to meet any criteria in Chapter 12 through Chapter 20 shall be permitted to protect light and ordinary hazard occupancies.
Standard-response CMSA sprinklers designed to meet any criteria in Chapter 12 through Chapter 20 shall be permitted to protect ordinary hazard occupancies.
Special sprinklers that are intended for the protection of specific hazards or construction features shall be permitted where such devices have been evaluated and listed for performance under the following conditions:
  1. Fire tests related to the intended hazard
  2. Distribution of the spray pattern with respect to wetting of floors and walls
  3. Distribution of the spray pattern with respect to obstructions
  4. Evaluation of the thermal sensitivity of the sprinkler
  5. Performance under horizontal or sloped ceilings
  6. Area of design
  7. Allowable clearance to ceilings
Special sprinklers shall maintain the following characteristics:
  1. K-factor size shall be in accordance with 6.2.3.
  2. Temperature ratings shall be in accordance with Table 6.2.5.1.
  3. The protection area of coverage shall not exceed 400 ft2 (37 m2) for light hazard and ordinary hazard occupancies.
  4. The protection area of coverage shall not exceed 196 ft2 (18.2 m2) for extra hazard and high-piled storage occupancies.
Where dry sprinklers are connected to wet pipe sprinkler systems protecting areas subject to freezing temperatures, the minimum exposed length of the barrel of the dry sprinkler shall be in accordance with Table 8.4.9.1(a) or Table 8.4.9.1(b).
Table 8.4.9.1(a) Exposed Barrel Lengths for Dry Sprinklers (U.S. Customary Units)
Ambient Temperature Exposed to Discharge End of Sprinkler
(°F)
Minimum Exposed Barrel Length when Exposed to 40°F
(in.)
Minimum Exposed Barrel Length when Exposed to 50°F
(in.)
Minimum Exposed Barrel Length when Exposed to 60°F
(in.)
40 0 0 0
30 0 0 0
20 4 0 0
10 8 1 0
0 12 3 0
-10 14 4 1
-20 14 6 3
-30 16 8 4
-40 18 8 4
-50 20 10 6
-60 20 10 6
Table 8.4.9.1(b) Exposed Barrel Lengths for Dry Sprinklers (Metric Units)
Ambient Temperature Exposed to Discharge End of Sprinkler
(°C)
Minimum Exposed Barrel Length when Exposed to 4°C
(mm)
Minimum Exposed Barrel Length when Exposed to 10°C
(mm)
Minimum Exposed Barrel Length when Exposed to 16°C
(mm)
4 0 0 0
-1 0 0 0
-7 100 0 0
-12 200 25 0
-18 300 75 0
-23 350 100 25
-29 350 150 75
-34 400 200 100
-40 450 200 100
-46 500 250 150
-51 500 250 150
The minimum barrel length shall be measured from the face of the fitting to which the dry sprinkler is installed to the inside surface of the insulation, wall, or ceiling leading to the cold space, whichever is closest to the fitting.
Where dry sprinklers are connected to wet pipe sprinkler systems protecting insulated freezer structures, the clearance space around the sprinkler barrel shall be sealed.
Sprinklers shall be located, spaced, and positioned in accordance with the requirements of Section 8.5.
Sprinklers shall be positioned to provide protection of the area consistent with the overall objectives of this standard by controlling the positioning and allowable area of coverage for each sprinkler.
The requirements of 8.5.2 through 8.5.7 shall apply to all sprinkler types unless modified by more restrictive rules in Section 8.6 through Section 8.12.
The protection area of coverage per sprinkler (AS) shall be determined as follows:
  1. Along branch lines as follows:
    1. Determine distance between sprinklers (or to wall or obstruction in the case of the end sprinkler on the branch line) upstream and downstream
    2. Choose the larger of either twice the distance to the wall or the distance to the next sprinkler
    3. Define dimension as S
  2. Between branch lines as follows:
    1. Determine perpendicular distance to the sprinkler on the adjacent branch line (or to a wall or obstruction in the case of the last branch line) on each side of the branch line on which the subject sprinkler is positioned
    2. Choose the larger of either twice the distance to the wall or obstruction or the distance to the next sprinkler
    3. Define dimension as L
The protection area of coverage of the sprinkler shall be established by multiplying the S dimension by the L dimension, as follows:
The maximum allowable protection area of coverage for a sprinkler (As) shall be in accordance with the value indicated in the section for each type or style of sprinkler.
The maximum area of coverage of any sprinkler shall not exceed 400 ft2 (37 m2).
The maximum distance permitted between sprinklers shall be based on the centerline distance between adjacent sprinklers.
The maximum distance shall be measured along the slope of the ceiling.
The maximum distance permitted between sprinklers shall comply with the value indicated in the applicable section for each type or style of sprinkler.
The distance from sprinklers to walls shall not exceed one-half of the allowable maximum distance between sprinklers.
The distance from the wall to the sprinkler shall be measured perpendicular to the wall.
The distance from the wall to the sprinkler shall be measured to the wall behind furniture, such as wardrobes, cabinets, and trophy cases.
The distance from the wall to the sprinkler shall be measured to the wall when sprinklers are spaced near windows and no additional floor space is created.
The minimum distance permitted between a sprinkler and the wall shall comply with the value indicated in the applicable section for each type or style of sprinkler.
The distance from the wall to the sprinkler shall be measured perpendicular to the wall.
A minimum distance shall be maintained between sprinklers to prevent operating sprinklers from wetting adjacent sprinklers and to prevent skipping of sprinklers.
The minimum distance permitted between sprinklers shall comply with the value indicated in the applicable section for each type or style of sprinkler.
The distances between the sprinkler deflector and the ceiling above shall be selected based on the type of sprinkler and the type of construction.
For corrugated metal deck roofs up to 3 in. (75 mm) in depth, the distance shall be measured to the sprinkler from the bottom of the deck.
For decks deeper than 3 in. (75 mm), the distance shall be measured to the highest point on the deck.
For ceilings that have insulation installed directly against underside of the ceiling or roof structure, the deflector distance shall be measured from the bottom of the insulation and shall be in accordance with 8.5.4.1.3.1 or 8.5.4.1.3.2.
For insulation that is installed directly against the ceiling or roof structure and is installed flat and parallel to the ceiling or roof structure, the deflector distance shall be measured to the underside of the insulation.
For insulation that is installed in a manner that causes it to deflect or sag down from the ceiling or roof structure, the deflector distance shall be measured as half of the distance of the deflection from the insulation high point to the insulation low point.
If the deflection or sag in the insulation exceeds 6 in. (150 mm), the deflector distance shall be measured to the high point of the insulation.
The deflector shall not be positioned above the low point of the insulation.
Heat collectors shall not be used as a means to assist the activation of a sprinkler.
Deflectors of sprinklers shall be aligned parallel to ceilings, roofs, or the incline of stairs.
Sprinklers shall be located so as to minimize obstructions to discharge as defined in 8.5.5.2 and 8.5.5.3, or additional sprinklers shall be provided to ensure adequate coverage of the hazard. (See Figure A.8.5.5.1.)
Continuous or noncontinuous obstructions less than or equal to 18 in. (450 mm) below the sprinkler deflector that prevent the pattern from fully developing shall comply with 8.5.5.2.
Sprinklers shall be positioned in accordance with the minimum distances and special requirements of Section 8.6 through Section 8.12 so that they are located sufficiently away from obstructions such as truss webs and chords, pipes, columns, and fixtures.
Continuous or noncontinuous obstructions that interrupt the water discharge in a horizontal plane more than 18 in. (450 mm) below the sprinkler deflector in a manner to limit the distribution from reaching the protected hazard shall comply with 8.5.5.3.
Sprinklers shall be installed under fixed obstructions over 4 ft (1.2 m) in width.
Open grate flooring over 4 ft (1.2 m) in width shall require sprinkler protection below the grating.
Sprinklers shall be located below the obstruction and not more than 3 in. (75 mm) from the outside edge of the obstruction.
Where sprinklers are located adjacent to the obstruction, they shall be of the intermediate level rack type.
The deflector of automatic sprinklers installed under fixed obstructions shall be positioned no more than 12 in. (300 mm) below the bottom of the obstruction.
Sprinklers shall not be required under noncombustible obstructions over 4 ft (1.2 m) wide where the bottom of the obstruction is 24 in. (600 mm) or less above the floor or deck.
Sprinklers shall not be required under obstructions that are not fixed in place, such as conference tables.
Sprinklers installed under obstructions shall be of the same type (spray, CMSA, ESFR, residential) as installed at the ceiling except as permitted by 8.5.5.3.3.1.
Spray sprinklers shall be permitted to be utilized under overhead doors.
Sprinklers installed under open gratings shall be of the intermediate level/rack storage type or otherwise shielded from the discharge of overhead sprinklers.
In all closets and compartments, including those closets housing mechanical equipment, that are not larger than 400 ft3 (11.3 m3) in size, a single sprinkler at the highest ceiling level shall be sufficient without regard to obstructions or minimum distance to the wall.
Unless the requirements of 8.5.6.2, 8.5.6.3, 8.5.6.4, or 8.5.6.5 are met, the clearance between the deflector and the top of storage or contents of the room shall be 18 in. (450 mm) or greater.
Where other standards specify greater clearance to storage minimums, they shall be followed.
A minimum clearance to storage of 36 in. (900 mm) shall be permitted for special sprinklers.
A minimum clearance to storage of less than 18 in. (450 mm) between the top of storage and ceiling sprinkler deflectors shall be permitted where proven by successful large- scale fire tests for the particular hazard.
The clearance from the top of storage to sprinkler deflectors shall be not less than 36 in. (900 mm) where rubber tires are stored.
Sprinklers shall be permitted to be omitted from skylights not exceeding 32 ft2 (3.0 m2) in area, regardless of hazard classification, that are separated by at least 10 ft (3.0 m) horizontally from any other unprotected skylight or unprotected ceiling pocket.
When a sprinkler is installed directly beneath a skylight not exceeding 32 ft2 (3.0 m2), the distance to the ceiling shall be measured to the plane of the ceiling as if the skylight was not present.
Skylights not exceeding 32 ft2 (3.0 m2) shall be permitted to have a plastic cover.
All requirements of Section 8.5 shall apply to standard pendent and upright spray sprinklers except as modified in Section 8.6.
Except as permitted by 8.6.2.1.2, the protection area of coverage per sprinkler (As) shall be determined in accordance with 8.5.2.1.
The requirements of 8.6.2.1.1 shall not apply in a small room as defined in 3.3.22.
The protection area of coverage for each sprinkler in the small room shall be the area of the room divided by the number of sprinklers in the room.
The maximum allowable protection area of coverage for a sprinkler (As) shall be in accordance with the value indicated in Table 8.6.2.2.1(a) through Table 8.6.2.2.1(d).
Table 8.6.2.2.1(a) Protection Areas and Maximum Spacing of Standard Pendent and Upright Spray Sprinklers for Light Hazard
Construction Type System Type Maximum Protection Area Maximum Spacing
ft2 m2 ft m
Noncombustible unobstructed Hydraulically calculated 225 20.9 15 4.6
Noncombustible unobstructed Pipe schedule 200 18.6 15 4.6
Noncombustible obstructed Hydraulically calculated 225 20.9 15 4.6
Noncombustible obstructed Pipe schedule 200 18.6 15 4.6
Combustible unobstructed with no exposed members Hydraulically calculated 225 20.9 15 4.6
Combustible unobstructed with no exposed members Pipe schedule 200 18.6 15 4.6
Combustible unobstructed with exposed members 3 ft (910 mm) or more on center Hydraulically calculated 225 20.9 15 4.6
Combustible unobstructed with exposed members 3 ft (910 mm) or more on center Pipe schedule 200 18.6 15 4.6
Combustible unobstructed with members less than 3 ft (910 mm) on center All 130 12.1 15 4.6
Combustible obstructed with exposed members 3 ft (910 mm) or more on center All 168 15.6 15 4.6
Combustible obstructed with members less than 3 ft (910 mm) on center All 130 12.1 15 4.6
Combustible concealed spaces in accordance with 8.6.4.1.4 All 120 11.1 15
parallel to the slope 10 perpendicular to the slope*
4.6
parallel to the slope 3.0 perpendicular to the slope*
*See 8.6.4.1.4.4.
Table 8.6.2.2.1(b) Protection Areas and Maximum Spacing of Standard Pendent and Upright Spray Sprinklers for Ordinary Hazard
Construction Type System Type Protection Area Maximum Spacing
ft2 m2 ft m
All All 130 12.1 15 4.6
Table 8.6.2.2.1(c) Protection Areas and Maximum Spacing of Standard Pendent and Upright Spray Sprinklers for Extra Hazard
Construction Type System Type Protection Area Maximum Spacing
ft2 m2 ft m
All Pipe schedule 90 8.4 12* 3.7*
All Hydraulically calculated with density ≥0.25 100 9.3 12* 3.7*
All Hydraulically calculated with density <0.25 130 12.1 15 4.6
*In buildings where solid structural members create bays up to 25 ft (7.6 m) wide, maximum spacing between sprinklers is permitted up to 12 ft 6 in. (3.8 m).
Table 8.6.2.2.1(d) Protection Areas and Maximum Spacing of Standard Pendent and Upright Spray Sprinklers for High-Piled Storage
Construction Type System Type Protection Area Maximum Spacing
ft2 m2 ft m
All Hydraulically calculated with density ≥0.25 100 9.3 12* 3.7*
All Hydraulically calculated with density <0.25 130 12.1 15 4.6
*In buildings where solid structural members create bays up to 25 ft (7.6 m) wide, maximum spacing between sprinklers is permitted up to 12 ft 6 in. (3.8 m).
In any case, the maximum area of coverage of a sprinkler shall not exceed 225 ft2 (20.9 m2).
The maximum distance permitted between sprinklers shall comply with Table 8.6.2.2.1(a) through Table 8.6.2.2.1(d).
The distance from sprinklers to walls shall not exceed one-half of the allowable distance between sprinklers as indicated in Table 8.6.2.2.1(a) through Table 8.6.2.2.1(d).
The distance from the wall to the sprinkler shall be measured perpendicular to the wall.
The requirements of 8.6.3.2.1 shall not apply where walls are angled or irregular, and the maximum horizontal distance between a sprinkler and any point of floor area protected by that sprinkler shall not exceed 0.75 times the allowable distance permitted between sprinklers, provided the maximum perpendicular distance is not exceeded.
The requirements of 8.6.3.2.1 shall not apply within small rooms as defined in 3.3.22.
Sprinklers shall be permitted to be located not more than 9 ft (2.7 m) from any single wall.
Sprinkler spacing limitations of 8.6.3 and area limitations of Table 8.6.2.2.1(a) shall not be exceeded.
Under curved surfaces, the horizontal distance shall be measured at the floor level from the wall, or the intersection of the curved surface and the floor to the nearest sprinkler shall not be greater than one-half the allowable distance between sprinklers.
Sprinklers shall be located a minimum of 4 in. (100 mm) from a wall.
Unless the requirements of 8.6.3.4.2, 8.6.3.4.3, or 8.6.3.4.4 are met, sprinklers shall be spaced not less than 6 ft (1.8 m) on center.
Sprinklers shall be permitted to be placed less than 6 ft (1.8 m) on center where the following conditions are satisfied:
  1. Baffles shall be arranged to protect the actuating elements.
  2. Baffles shall be of solid and rigid material that will stay in place before and during sprinkler operation.
  3. Baffles shall be not less than 8 in. (200 mm) long and 6 in. (150 mm) high.
  4. The tops of baffles shall extend between 2 in. and 3 in. (50 mm and 75 mm) above the deflectors of upright sprinklers.
  5. The bottoms of baffles shall extend downward to a level at least even with the deflectors of pendent sprinklers.
In-rack sprinklers shall be permitted to be placed less than 6 ft (1.8 m) on center.
Old-style sprinklers protecting fur storage vaults shall be permitted to be placed less than 6 ft (1.8 m) on center.
Under unobstructed construction, the distance between the sprinkler deflector and the ceiling shall be a minimum of 1 in. (25 mm) and a maximum of 12 in. (300 mm) throughout the area of coverage of the sprinkler.
The requirements of 8.6.4.1.1.1 shall not apply where ceiling-type sprinklers (concealed, recessed, and flush types) have the operating element above the ceiling and the deflector located nearer to the ceiling where installed in accordance with their listing.
The requirements of 8.6.4.1.1.1 shall not apply for light and ordinary hazard occupancies with ceilings of noncombustible or limited-combustible construction where either 8.6.4.1.1.3(A) or 8.6.4.1.1.3(B) applies.
Where a vertical change in ceiling elevation within the area of coverage of the sprinkler creates a distance of more than 36 in. (900 mm) between the upper ceiling and the sprinkler deflector, a vertical plane extending down from the ceiling at the change in elevation shall be considered a wall for the purpose of sprinkler spacing as shown in Figure 8.6.4.1.1.3(A).
FIGURE 8.6.4.1.1.3(A) Vertical Change in Ceiling Elevation Greater Than 36 in. (914 mm).
Where the distance between the upper ceiling and the sprinkler deflector is less than or equal to 36 in. (900 mm), the sprinklers shall be permitted to be spaced as though the ceiling was flat, provided the obstruction rules are observed as shown in Figure 8.6.4.1.1.3(B).
FIGURE 8.6.4.1.1.3(B) Vertical Change in Ceiling Elevation Less Than or Equal to 36 in. (914 mm).
Under obstructed construction, the sprinkler deflector shall be located in accordance with one of the following arrangements:
  1. Installed with the deflectors within the horizontal planes of 1 in. to 6 in. (25 mm to 150 mm) below the structural members and a maximum distance of 22 in. (550 mm) below the ceiling/roof deck
  2. Installed with the deflectors at or above the bottom of the structural member to a maximum of 22 in. (550 mm) below the ceiling/roof deck where the sprinkler is installed in conformance with 8.6.5.1.2
  3. Installed in each bay of obstructed construction, with the deflectors located a minimum of 1 in. (25 mm) and a maximum of 12 in. (300 mm) below the ceiling
  4. Installed with the deflectors within the horizontal planes 1 in. to 6 in. (25 mm to 150 mm) below composite wood joists to a maximum distance of 22 in. (550 mm) below the ceiling/roof deck only where joist channels are firestopped to the full depth of the joists with material equivalent to the web construction so that individual channel areas do not exceed 300 ft2 (27.9 m2)
  5. *Installed with deflectors of sprinklers under concrete tee construction with stems spaced less than 71/2 ft (2.3 m) on centers, regardless of the depth of the tee, located at or above a horizontal plane 1 in. (25 mm) below the bottom of the stems of the tees and complying with Table 8.6.5.1.2
Unless the requirements of 8.6.4.1.3.2 or 8.6.4.1.3.3 are met, sprinklers under or near the peak of a roof or ceiling shall have deflectors located not more than 36 in. (900 mm) vertically down from the peak as indicated in Figure 8.6.4.1.3.1(a) and Figure 8.6.4.1.3.1(b).
FIGURE 8.6.4.1.3.1(a) Sprinklers Under Pitched Roof with Sprinkler Directly Under Peak; Branch Lines Run Up Slopes.
FIGURE 8.6.4.1.3.1(b) Sprinklers at Pitched Roof; Branch Lines Run Up Slopes.
Under saw-toothed roofs, sprinklers at the highest elevation shall not exceed a distance of 36 in. (900 mm) measured down the slope from the peak.
Under a steeply pitched surface, the distance from the peak to the deflectors shall be permitted to be increased to maintain a horizontal clearance of not less than 24 in. (600 mm) from other structural members as indicated in Figure 8.6.4.1.3.3.
FIGURE 8.6.4.1.3.3 Horizontal Clearance for Sprinkler at Peak of Pitched Roof.
Sprinklers under a roof or ceiling in combustible concealed spaces of wood joist or wood truss construction with members less than 3 ft (900 mm) on center with a slope having a pitch of 4 in 12 or greater shall be positioned in accordance with Figure 8.6.4.1.4 and the requirements of 8.6.4.1.4.1 through 8.6.4.1.4.6.
*The 5 ft minimum dimension is measured from the intersection of the upper and lower truss chords or the wood rafters and ceiling joists.
FIGURE 8.6.4.1.4 Sprinklers Under Roof or Ceiling in Combustible Concealed Spaces of Wood Joist or Wood Truss Construction with Members Less Than 3 ft (0.91 m) on Center with a Slope Having a Pitch of 4 in 12 or Greater.
Sprinklers shall be quick-response.
Sprinklers shall be installed so that a row of sprinklers is installed within 12 in. (300 mm) horizontally of the peak and between 1 in. and 12 in. (25 mm and 300 mm) down from the bottom of the top chord member.
Sprinklers shall be installed so that the sprinklers installed along the eave are located not less than 5 ft (1.5 m) from the intersection of the upper and lower truss chords or the wood rafters and ceiling joists.
Sprinklers installed where the dimension perpendicular to the slope exceeds 8 ft (2.4 m) shall have a minimum pressure of 20 psi (1.4 bar).
The requirements of 8.6.4.1.4.3 or 8.6.4.1.4.4 shall not apply to sprinklers installed at the corner of the eave of a hip type roof where located directly under the hip line spaced in accordance with 8.6.3.2.3 or located along the eave spaced on the slope plane not less than 5 ft (1.5 m) from the intersection of the upper and lower truss chords or the wood rafters and ceiling joists.
The special requirements of 8.6.2.2.1 and 8.6.4.1.4 shall not apply when the exposed combustible sheathing in the roof or ceiling space are constructed of pressure impregnated fire retardant-treated wood as defined by NFPA 703.
Unless the requirements of 8.6.4.1.5.2 are met, where two sets of joists are under a roof or ceiling, and no flooring is over the lower set, sprinklers shall be installed above and below the lower set of joists where a clearance of 6 in. (150 mm) or more is between the top of the lower joist and the bottom of the upper joist as indicated in Figure 8.6.4.1.5.1.
FIGURE 8.6.4.1.5.1 Arrangement of Sprinklers Under Two Sets of Open Joists — No Sheathing on Lower Joists.
Sprinklers shall be permitted to be omitted from below the lower set of joists where at least 18 in. (450 mm) is maintained between the sprinkler deflector and the top of the lower joist.
Unless the requirements of 8.6.4.2.2 or 8.6.4.2.3 are met, deflectors of sprinklers shall be aligned parallel to ceilings, roofs, hips, or the incline of stairs.
Where sprinklers are installed in the peak below a sloped ceiling or roof surface, the sprinkler shall be installed with the deflector horizontal.
Roofs having a pitch not exceeding 2 in 12 (16.7 percent) are considered horizontal in the application of 8.6.4.2, and sprinklers shall be permitted to be installed with deflectors horizontal.
Sprinklers shall be located so as to minimize obstructions to discharge as defined in 8.6.5.2 and 8.6.5.3, or additional sprinklers shall be provided to ensure adequate coverage of the hazard.
Sprinklers shall be arranged to comply with one of the following arrangements:
  1. Subsection 8.5.5.2, Table 8.6.5.1.2, and Figure 8.6.5.1.2(a) shall be followed.
  2. Sprinklers shall be permitted to be spaced on opposite sides of obstructions not exceeding 4 ft (1.2 m) in width, provided the distance from the centerline of the obstruction to the sprinklers does not exceed one-half the allowable distance permitted between sprinklers.
  3. Obstructions located against the wall and that are not over 30 in. (750 mm) in width shall be permitted to be protected in accordance with Figure 8.6.5.1.2(b).
  4. Obstructions located against the wall and that are not over 24 in. (600 mm) in width shall be permitted to be protected in accordance with Figure 8.6.5.1.2(c). The maximum distance between the sprinkler and the wall shall be measured from the sprinkler to the wall behind the obstruction and not to the face of the obstruction.
Table 8.6.5.1.2 Positioning of Sprinklers to Avoid Obstructions to Discharge [Standard Spray Upright/Standard Spray Pendent (SSU/SSP)]
Distance from Sprinklers to Side of Obstruction (A) Maximum Allowable Distance of Deflector Above Bottom of Obstruction (B)
[in. (mm)]
Less than 1 ft (300 mm) 0 (0)
1 ft (300 mm) to less than 1 ft 6 in. (450 mm) 21/2 (65)
1 ft 6 in. (450 mm) to less than 2 ft (600 mm) 31/2 (90)
2 ft (600 mm) to less than 2 ft 6 in. (750 mm) 51/2 (140)
2 ft 6 (750 mm) in. to less than 3 ft (900 mm) 71/2 (190)
3 ft (900 mm) to less than 3 ft 6 in. (1.1 m) 91/2 (240)
3 ft 6 in. (1.1 m) to less than 4 ft (1.2 m) 12 (300)
4 ft (1.2 m) to less than 4 ft 6 in. (1.4 m) 14 (350)
4 ft 6 in. (1.4 m) to less than 5 ft (1.5 m) 161/2 (420)
5 ft (1.5 m) to less than 5 ft 6 in. (1.7 m) 18 (450)
5 ft 6 in. (1.7 m) to less than 6 ft (1.8 m) 20 (510)
6 ft (1.8 m) to less than 6 ft 6 in. (2.0 m) 24 (600)
6 ft 6 in. (2.0 m) to less than 7 ft (2.1 m) 30 (750)
7 ft (2.1 m) to less than 7 ft 6 in. (2.3 m) 35 (875)
For SI units, 1 in. = 25.4 mm; 1 ft = 0.3048 m.
Note: For A and B, refer to Figure 8.6.5.1.2(a).
FIGURE 8.6.5.1.2(a) Positioning of Sprinkler to Avoid Obstruction to Discharge (SSU/SSP).
FIGURE 8.6.5.1.2(b) Obstruction Against Wall (SSU/SSP).
FIGURE 8.6.5.1.2(c) Obstructions Against Walls (SSU/SSP).
Continuous or noncontinuous obstructions less than or equal to 18 in. (450 mm) below the sprinkler deflector that prevent the pattern from fully developing shall comply with 8.6.5.2.
Regardless of the rules of 8.6.5.2, solid continuous obstructions, where the top of the obstruction is level with or above the plane of the deflector, shall meet the applicable requirements of 8.6.5.1.2.
Unless the requirements of 8.6.5.2.1.4 through 8.6.5.2.1.9 are met, sprinklers shall be positioned away from obstructions a minimum distance of three times the maximum dimension of the obstruction (e.g., structural members, pipe, columns, and fixtures) in accordance with Figure 8.6.5.2.1.3(a) and Figure 8.6.5.2.1.3(b).
FIGURE 8.6.5.2.1.3(a) Minimum Distance from an Obstruction in the Vertical Orientation (SSU/SSP).
FIGURE 8.6.5.2.1.3(b) Minimum Distance from an Obstruction in the Horizontal Orientation (SSU/SSP).
The maximum clear distance required shall be 24 in. (600 mm).
The maximum clear distance shall not be applied to obstructions in the vertical orientation (e.g., columns).
For light and ordinary hazard occupancies, structural members only shall be considered when applying the requirements of 8.6.5.2.1.3.
Sprinklers shall be permitted to be spaced on opposite sides of the obstruction where the distance from the centerline of the obstruction to the sprinklers does not exceed one-half the allowable distance between sprinklers.
Sprinklers shall be permitted to be located one-half the distance between the obstructions where the obstruction consists of open trusses 20 in. (500 mm) or greater apart [24 in. (600 mm) on center], provided that all truss members are not greater than 4 in. (100 mm) (nominal) in width.
Sprinklers shall be permitted to be installed on the centerline of a truss or bar joist or directly above a beam, provided that the truss chord or beam dimension is not more than 8 in. (200 mm) and the sprinkler deflector is located at least 6 in. (150 mm) above the structural member and where the sprinkler is positioned at a distance three times greater than the maximum dimension of the web members away from the web members.
The requirements of 8.6.5.2.1.3 shall not apply to sprinkler system piping less than 3 in. (80 mm) in diameter.
The requirements of 8.6.5.2.1.3 shall not apply to sprinklers positioned with respect to obstructions in accordance with 8.6.5.1.2.
Sprinklers shall be permitted to be placed without regard to the blades of ceiling fans less than 60 in. (1.5 m) in diameter, provided the plan view of the fan is at least 50 percent open.
The distance from sprinklers to privacy curtains, freestanding partitions, room dividers, and similar obstructions in light hazard occupancies shall be in accordance with Table 8.6.5.2.2 and Figure 8.6.5.2.2.
Table 8.6.5.2.2 Suspended or Floor-Mounted Obstructions in Light Hazard Occupancies Only (SSU/SSP)
Horizontal Distance (A) Minimum Vertical Distance Below Deflector (B)
[in. (mm)]
6 in. (150 mm) or less 3 (75)
More than 6 in. (150 mm) to 9 in. (225 mm) 4 (100)
More than 9 in. (225 mm) to 12 in. (300 mm) 6 (150)
More than 12 in. (300 mm) to 15 in. (375 mm) 8 (200)
More than 15 in. (375 mm) to 18 in. (400 mm) 91/2 (240)
More than 18 in. (400 mm) to 24 in. (600 mm) 121/2 (315)
More than 24 in. (600 mm) to 30 in. (750 mm) 151/2 (395)
More than 30 in. (750 mm) 18 (450)
For SI units, 1 in. = 25.4 mm.
Note: For A and B, refer to Figure 8.6.5.2.2.
FIGURE 8.6.5.2.2 Suspended or Floor-Mounted Obstruction in Light Hazard Occupancies Only (SSU/SSP).
In light hazard occupancies, privacy curtains, as shown in Figure 8.6.5.2.2, shall not be considered obstructions where all of the following are met:
  1. The curtains are supported by fabric mesh on ceiling track.
  2. Openings in the mesh are equal to 70 percent or greater.
  3. The mesh extends a minimum of 22 in. (550 mm) down from ceiling.
Continuous or noncontinuous obstructions that interrupt the water discharge in a horizontal plane more than 18 in. (450 mm) below the sprinkler deflector in a manner to limit the distribution from reaching the protected hazard shall comply with 8.6.5.3.
The requirements of 8.6.5.3 shall also apply to obstructions 18 in. (450 mm) or less below the sprinkler for light and ordinary hazard occupancies.
Sprinklers shall be installed under fixed obstructions over 4 ft (1.2 m) wide.
Sprinklers shall not be required below obstructions that are not fixed in place, such as conference tables.
Sprinklers installed under open gratings shall be of the intermediate level/rack storage type or otherwise shielded from the discharge of overhead sprinklers.
The deflector of automatic sprinklers installed under fixed obstructions shall be positioned no more than 12 in. (300 mm) below the bottom of the obstruction.
Sprinklers installed under round ducts shall be of the intermediate level/rack storage type or otherwise shielded from the discharge of overhead sprinklers.
The clearance between the deflector and the top of storage shall be 18 in. (450 mm) or greater.
The 18 in. (450 mm) dimension shall not limit the height of shelving on a wall or shelving against a wall in accordance with 8.6.6, 8.7.6, 8.8.6, and Section 8.9.
Where shelving is installed on a wall and is not directly below sprinklers, the shelves, including storage thereon, shall be permitted to extend above the level of a plane located 18 in. (450 mm) below ceiling sprinkler deflectors.
Shelving, and any storage thereon, directly below the sprinklers shall not extend above a plane located 18 in. (450 mm) below the ceiling sprinkler deflectors.
Where other standards specify greater clearance to storage minimums, they shall be followed.
Except as provided in 8.6.7.2 and 8.6.7.3, sprinklers shall be required in all ceiling pockets.
Sprinklers shall not be required in ceiling pockets where all of the following are met:
  1. The total volume of the unprotected ceiling pocket does not exceed 1000 ft3 (28 m3).
  2. The depth of the unprotected ceiling pocket does not exceed 36 in. (900 mm).
  3. The entire floor under the unprotected ceiling pocket is protected by sprinklers at the lower ceiling elevation.
  4. *The total size of all unprotected ceiling pockets in the same compartment within 10 ft (3 m) of each other does not exceed 1000 ft3 (28 m3).
  5. The unprotected ceiling pocket has noncombustible or limited-combustible finishes.
  6. Quick-response sprinklers are utilized throughout the compartment.
Sprinklers shall not be required in skylights and similar pockets in accordance with 8.5.7.
All requirements of Section 8.5 shall apply to sidewall standard spray sprinklers except as modified in Section 8.7.
The protection area of coverage per sprinkler (As) shall be determined as follows:
  1. Along the wall as follows:
    1. Determine the distance between sprinklers along the wall (or to the end wall or obstruction in the case of the end sprinkler on the branch line) upstream and downstream
    2. Choose the larger of either twice the distance to the end wall or the distance to the next sprinkler
    3. Define dimension as S
  2. Across the room as follows:
    1. Determine the distance from the wall on which the sprinkler is installed to the wall opposite the sprinklers or to the midpoint of the room where sprinklers are installed on two opposite walls (see 8.7.3.1.5 and 8.7.3.1.6)
    2. Define dimension as L
The protection area of the sprinkler shall be established by multiplying the S dimension by the L dimension, as follows:
The maximum allowable protection area of coverage for a sprinkler (As) shall be in accordance with the value indicated in Table 8.7.2.2.1.
Table 8.7.2.2.1 Protection Areas and Maximum Spacing (Standard Sidewall Spray Sprinkler)
Light Hazard Ordinary Hazard
Combustible Ceiling Finish Noncombustible or Limited-Combustible Ceiling Finish Combustible Ceiling Finish Noncombustible or Limited-Combustible Ceiling Finish
Maximum distance along the wall (S) (ft) [m] 14 [4.3] 14 [4.3] 10 [3.0] 10 [3.0]
Maximum room width (L) (ft) [m] 12 [3.7] 14 [4.3] 10 [3.0] 10 [3.0]
Maximum protection area (ft2) [m] 120 [11.1] 196 [18.2] 80 [7.4] 100 [9.3]
In any case, the maximum area of coverage of a sprinkler shall not exceed 196 ft2 (18.2 m2).
The maximum distance permitted between sidewall spray sprinklers shall be based on the centerline distance between sprinklers on the branch line.
The maximum distance between sidewall spray sprinklers or to a wall shall be measured along the slope of the ceiling.
Where sidewall spray sprinklers are installed along the length of a single wall of rooms or bays, they shall be spaced in accordance with the maximum spacing provisions of Table 8.7.2.2.1.
Sidewall spray sprinklers shall not be installed back-to-back without being separated by a continuous lintel or soffit.
The maximum width of the lintel or soffit shall not exceed 16 in. (400 mm).
The maximum width of the lintel or soffit can exceed 16 in. (400 mm) when a pendent sprinkler is installed under the lintel or soffit.
Where sidewall spray sprinklers are installed on two opposite walls or sides of bays, the maximum width of the room or bay shall be permitted to be up to 24 ft (7.3 m) for light hazard occupancy or 20 ft (6.1 m) for ordinary hazard occupancy, with spacing as required by Table 8.7.2.2.1.
Sidewall spray sprinklers shall be permitted to be installed on opposing or adjacent walls, provided no sprinkler is located within the maximum protection area of another sprinkler.
Where sidewall standard spray sprinklers are installed to protect areas below overhead doors within ordinary hazard occupancy spaces or rooms, protection area and maximum sprinkler spacing for light hazard as specified in Table 8.7.2.2.1 shall be permitted under the overhead doors.
The distance from sprinklers to the end walls shall not exceed one-half of the allowable distance permitted between sprinklers as indicated in Table 8.7.2.2.1.
Sprinklers shall be located a minimum of 4 in. (100 mm) from an end wall.
The distance from the wall to the sprinkler shall be measured perpendicular to the wall.
Sprinklers shall be spaced not less than 6 ft (1.8 m) on center unless required by 8.7.4.1.3.1 or unless the sprinklers are separated by baffles that comply with the following:
  1. Baffles shall be arranged to protect the actuating elements.
  2. Baffles shall be of solid and rigid material that will stay in place before and during sprinkler operation.
  3. Baffles shall be not less than 8 in. (200 mm) long and 6 in. (150 mm) high.
  4. The tops of baffles shall extend between 2 in. and 3 in. (50 mm and 75 mm) above the deflectors.
  5. The bottoms of baffles shall extend downward to a level at least even with the deflectors.
Unless the requirements of 8.7.4.1.1.2 are met, sidewall sprinkler deflectors shall be located not more than 6 in. (150 mm) or less than 4 in. (100 mm) from ceilings.
Horizontal sidewall sprinklers shall be permitted to be located in a zone 6 in. to 12 in. (150 mm to 300 mm) or 12 in. to 18 in. (300 mm to 450 mm) below noncombustible and limited-combustible ceilings where listed for such use.
Vertical sidewall sprinkler deflectors shall be located not more than 6 in. (150 mm) or less than 4 in. (100 mm) from the wall from which they are projecting.
Horizontal sidewall sprinkler deflectors shall be located no more than 6 in. (150 mm), and shall be permitted to be located with their deflectors less than 4 in. (100 mm), from the wall on which they are mounted.
Where soffits used for the installation of sidewall sprinklers exceed 8 in. (200 mm) in width or projection from the wall, additional sprinklers shall be installed below the soffit.
Where soffits used for the installation of sidewall sprinklers are less than or equal to 8 in. (200 mm) in width or projection from the wall, additional sprinklers shall not be required below the soffit when the sidewall sprinkler is installed on the soffit.
A sidewall sprinkler shall be permitted to be installed under a soffit when both the minimum distance from the sprinkler deflector to the bottom of the soffit and maximum distance from the sprinkler deflector to the high ceiling is maintained.
Where soffits are used for the installation of sidewall sprinklers, the sprinklers and soffits shall be installed in accordance with 8.7.4.1.4.1, 8.7.4.1.4.2, or 8.7.4.1.4.3.
Where soffits exceed more than 8 in. (200 mm) in width or projection from the wall, pendent sprinklers shall be installed under the soffit.
Sidewall sprinklers shall be permitted to be installed in the face of a soffit located directly over cabinets, without requiring additional sprinklers below the soffit or cabinets, where the soffit does not project horizontally more than 12 in. (300 mm) from the wall.
Where sidewall sprinklers are more than 36 in. (900 mm) above the top of cabinets, the sprinkler shall be permitted to be installed on the wall above the cabinets where the cabinets are no greater than 12 in. (300 mm) from the wall.
Deflectors of sprinklers shall be aligned parallel to ceilings or roofs.
Sidewall sprinklers, where installed under a sloped ceiling with a slope exceeding 2 in 12, shall be located at the high point of the slope and positioned to discharge downward along the slope.
Sprinklers shall be located so as to minimize obstructions to discharge as defined in 8.5.5.2 and 8.5.5.3, or additional sprinklers shall be provided to ensure adequate coverage of the hazard.
Sidewall sprinklers shall be installed no closer than 4 ft (1.2 m) from light fixtures or similar obstructions.
The distance between light fixtures or similar obstructions located more than 4 ft (1.2 m) from the sprinkler shall be in conformity with Table 8.7.5.1.3 and Figure 8.7.5.1.3.
Table 8.7.5.1.3 Positioning of Sprinklers to Avoid Obstructions (Standard Sidewall Spray Sprinklers)
Distance from Sidewall Sprinkler to Side of Obstruction (A) Maximum Allowable Distance of Deflector Above Bottom of Obstruction (B) [in. (mm)]
Less than 4 ft (1.2 m) Not allowed
4 ft (1.2 m) to less than 5 ft (1.5 m) 1 (25)
5 ft (1.5 m) to less than 5 ft 6 in. (1.7 m) 2 (50)
5 ft 6 in. (1.7 m) to less than 6 ft (1.8 m) 3 (75)
6 ft (1.8 m) to less than 6 ft 6 in. (2.0 m) 4 (100)
6 ft 6 in. (2.0 m) to less than 7 ft (2.1 m) 6 (150)
7 ft (2.1 m) to less than 7 ft 6 in. (2.3 m) 7 (175)
7 ft 6 in. (2.3 m) to less than 8 ft (2.4 m) 9 (225)
8 ft (2.4 m) to less than 8 ft 6 in. (2.6 m) 11 (275)
8 ft 6 in. (2.6 m) or greater 14 (350)
Note: For A and B, refer to Figure 8.7.5.1.3.
FIGURE 8.7.5.1.3 Positioning of Sprinkler to Avoid Obstruction (Standard Sidewall Spray Sprinklers).
Obstructions projecting from the same wall as the one on which the sidewall sprinkler is mounted shall be in accordance with Table 8.7.5.1.4 and Figure 8.7.5.1.4.
Table 8.7.5.1.4 Positioning of Sprinklers to Avoid Obstructions Along Wall (Standard Sidewall Spray Sprinklers)
Distance from Sidewall Sprinkler to Side of Obstruction (A) Maximum Allowable Distance of Deflector Above Bottom of Obstruction (B)
[in. (mm)]
4 in.(100 mm) to less than 6 in. (150 mm) 1 (25)
6 in. (150 mm) to less than 1 ft (300 mm) 2 (50)
1 ft (300 mm) to less than 1 ft 6 in. (450 mm) 3 (75)
1 ft 6 in. (450 mm) to less than 2 ft (600 mm) 41/2 (115)
2 ft (600 mm) to less than 2 ft 6 in. (750 mm) 53/4 (145)
2 ft 6 in. (750 mm) to less than 3 ft (900 mm) 7 (175)
3 ft (900 mm) to less than 3 ft 6 in. (1.1 m) 8 (200)
3 ft 6 in. (1.1 m) to less than 4 ft (1.2 m) 91/4 (230)
4 ft (1.2 m) to less than 4 ft 6 in. (1.4 m) 10 (250)
4 ft 6 in. (1.4 m) to less than 5 ft (1.5 m) 111/2 (290)
5 ft (1.5 m) to less than 5 ft 6 in. (1.7 m) 123/4 (325)
5 ft 6 in. (1.7 m) to less than 6 ft (1.8 m) 14 (350)
6 ft (1.8 m) to less than 6 ft 6 in. (2.0 m) 15 (380)
6 ft 6 in. (2.0 m) to less than 7 ft (2.2 m) 161/4 (410)
7 ft (2.2 m) to less than 7 ft 6 in. (2.3 m) 171/2 (440)
For SI units, 1 in. = 25.4 mm; 1 ft = 0.3048 m.
Note: For A and B, refer to Figure 8.7.5.1.4(a).
FIGURE 8.7.5.1.4 Positioning of Sprinkler to Avoid Obstruction Along Wall (Standard Sidewall Spray Sprinklers).
Isolated obstructions projecting from the same wall as the one on which the sidewall sprinkler is mounted shall be located a minimum of 4 in. (100 mm) from the sidewall sprinkler.
Sprinklers shall be permitted to be spaced on opposite sides of obstructions less than 4 ft (1.2 m) in width where the distance from the centerline of the obstruction to the sprinklers does not exceed one-half the allowable distance between sprinklers.
Obstructions on the wall opposite from the sidewall sprinkler shall be permitted where the obstruction is up to 2 ft (600 mm) deep and 2 ft (600 mm) wide.
Continuous or noncontinuous obstructions less than or equal to 18 in. (450 mm) below the sprinkler deflector that prevent the pattern from fully developing shall comply with this section.
Regardless of the rules of this section, solid continuous obstructions shall meet the requirements of 8.7.5.1.2 and 8.7.5.1.3.
Unless the requirements of 8.7.5.2.1.4 or 8.7.5.2.1.5 are met, sprinklers shall be positioned away from obstructions a minimum distance of three times the maximum dimension of the obstruction (e.g., truss webs and chords, pipe, columns, and fixtures) in accordance with Figure 8.7.5.2.1.3(a) and Figure 8.7.5.2.1.3(b).
A ≥ 3C or 3D
(Use dimension C or D, whichever is greater)
FIGURE 8.7.5.2.1.3(a) Minimum Distance from an Obstruction in the Vertical Orientation (Standard Sidewall Spray Sprinklers).
A ≥ 3C or 3D
A ≤ 24 in. (600 mm)
(Use dimension C or D, whichever is greater)
FIGURE 8.7.5.2.1.3(b) Minimum Distance from an Obstruction in the Horizontal Orientation (Standard Sidewall Spray Sprinklers).
The maximum clear distance required to obstructions in the horizontal orientation (e.g., light fixtures and truss chords) shall be 24 in. (600 mm).
The maximum clear distance shall not be applied to obstructions in the vertical orientation (e.g., columns).
The requirements of 8.7.5.2.1.3 shall not apply to sprinkler system piping less than 3 in. (80 mm) in diameter.
The requirements of 8.7.5.2.1.3 shall not apply where sprinklers are positioned with respect to obstructions in accordance with 8.7.5.1.2, 8.7.5.1.3, and 8.7.5.1.4.
Sprinklers shall be permitted to be placed without regard to the blades of ceiling fans less than 60 in. (1.5 m) in diameter, provided the plan view of the fan is at least 50 percent open.
The distance from sprinklers to privacy curtains, free-standing partitions, room dividers, and similar obstructions in light hazard occupancies shall be in accordance with Table 8.7.5.2.2 and Figure 8.7.5.2.2.
Table 8.7.5.2.2 Suspended or Floor-Mounted Obstructions (Standard Sidewall Spray Sprinklers) in Light Hazard Occupancies Only
Horizontal Distance (A) Minimum Vertical Distance Below Deflector (B)
[in. (mm)]
6 in. (150 mm) or less 3 (75)
More than 6 in. (150 mm) to 9 in. (225 mm) 4 (100)
More than 9 in. (225 mm) to 12 in. (300 mm) 6 (150)
More than 12 in. (300 mm) to 15 in. (375 mm) 8 (200)
More than 15 in. (375 mm) to 18 in. (450 mm) 91/2 (240)
More than 18 in. (450 mm) to 24 in. (600 mm) 121/2 (315)
More than 24 in. (600 mm) to 30 in. (750 mm) 151/2 (390)
More than 30 in. (750 mm) 18 (450)
For SI units, 1 in. = 25.4 mm.
Note: For A and B, refer to Figure 8.7.5.2.2.
FIGURE 8.7.5.2.2 Suspended or Floor-Mounted Obstruction (Standard Sidewall Spray Sprinklers) in Light Hazard Occupancy Only.
In light hazard occupancies, privacy curtains, as shown in Figure 8.7.5.2.2, shall not be considered obstructions where all of the following are met:
  1. The curtains are supported by fabric mesh on ceiling track.
  2. Openings in the mesh are equal to 70 percent or greater.
  3. The mesh extends a minimum of 22 in. (550 mm) down from ceiling.
Continuous or noncontinuous obstructions that interrupt the water discharge in a horizontal plane more than 18 in. (450 mm) below the sprinkler deflector in a manner to limit the distribution from reaching the protected hazard shall comply with this section.
Sprinklers shall be installed under fixed obstructions over 4 ft (1.2 m) wide such as ducts, decks, open grate flooring, cutting tables, and overhead doors.
Sprinklers shall not be required under obstructions that are not fixed in place such as conference tables.
The clearance between the deflector and the top of storage shall be 18 in. (450 mm) or greater.
All requirements of Section 8.5 shall apply to extended coverage upright and pendent sprinklers except as modified in Section 8.8.
The protection area of coverage (As) for extended coverage sprinklers shall be not less than that prescribed by the listing.
Listing dimensions shall be even-numbered square protection areas as shown in Table 8.8.2.1.2.
Table 8.8.2.1.2 Protection Areas and Maximum Spacing (Extended Coverage Upright and Pendent Spray Sprinklers)
Construction Type Light Hazard Ordinary Hazard Extra Hazard High-Piled Storage
Protection Area
ft2 (m2)
Spacing
ft (m)
Protection Area
ft2 (m2)
Spacing
ft (m)
Protection Area
ft2 (m2)
Spacing
ft (m)
Protection Area
ft2 (m2)
Spacing
ft (m)
Unobstructed 400 (37) 20 (6.1) 400 (37) 20 (6.1)
324 (30) 18 (5.5) 324 (30) 18 (5.5)
256 (23.8) 16 (4.9) 256 (23.8) 16 (4.9)
196 (18.2) 14 (4.3) 196 (18.2) 14 (4.3) 196 (18.2) 14 (4.3)
144 (13.4) 12 (3.7) 144 (13.4) 15 (4.6) 144 (13.4) 15 (4.6)
Obstructed noncombustible (when specifically listed for such use) 400 (37) 20 (6.1) 400 (37) 20 (6.1)
324 (30) 18 (5.5) 324 (30) 18 (5.5)
256 (23.8) 16 (4.9) 256 (23.8) 16 (4.9)
196 (18.2) 14 (4.3) 196 (18.2) 14 (4.3) 196 (18.2) 14 (4.3)
144 (13.4) 12 (3.7) 144 (13.4) 15 (4.6) 144 (13.4) 15 (4.6)
Obstructed combustible N/A N/A N/A N/A N/A N/A N/A N/A
For SI units, 1 ft = 0.3048 m; 1 ft2 = 0.0929 m2.
Determination of the protection area of coverage and sprinkler spacing for sprinklers listed for extended coverage extra hazard or high-piled storage shall be permitted to be spaced in accordance with the requirements of 8.5.2 and 8.5.3 and shall not exceed 14 ft (4.3 m) maximum spacing and 196 ft2 (18.2 m2) maximum area per sprinkler or 15 ft (4.6 m) maximum spacing and 144 ft2 (13.5 m2) maximum area per sprinkler.
The maximum allowable area of coverage for a sprinkler (As) shall be in accordance with the value indicated in Table 8.8.2.1.2.
In any case, the maximum area of coverage of a sprinkler shall not exceed 400 ft2 (37 m2).
The maximum distance permitted between sprinklers shall be based on the centerline distance between sprinklers on the branch line or on adjacent branch lines.
The maximum distance shall be measured along the slope of the ceiling.
The maximum distance permitted between sprinklers shall comply with Table 8.8.2.1.2.
The distance from sprinklers to walls shall not exceed one-half of the allowable distance permitted between sprinklers as indicated in Table 8.8.2.1.2.
The distance from the wall to the sprinkler shall be measured perpendicular to the wall.
Where walls are angled or irregular, the maximum horizontal distance between a sprinkler and any point of floor area protected by that sprinkler shall not exceed 0.75 times the allowable distance permitted between sprinklers.
Sprinklers shall be located a minimum of 4 in. (100 mm) from a wall unless listed for distances less than 4 in. (100 mm).
Unless the requirements of 8.8.3.4.2 are met, sprinklers shall be spaced not less than 8 ft (2.4 m) on center.
Sprinklers shall be permitted to be placed less than 8 ft (2.4 m) on center where the following conditions are satisfied:
  1. Baffles shall be arranged to protect the actuating elements.
  2. Baffles shall be of solid and rigid material that will stay in place before and during sprinkler operation.
  3. Baffles shall be not less than 8 in. (200 mm) long and 6 in. (150 mm) high.
  4. The tops of baffles shall extend between 2 in. and 3 in. (50 mm and 75 mm) above the deflectors of upright sprinklers.
  5. The bottoms of baffles shall extend downward to a level at least even with the deflectors of pendent sprinklers.
Under unobstructed construction, the distance between the sprinkler deflector and the ceiling shall be a minimum of 1 in. (25 mm) and a maximum of 12 in. (300 mm) throughout the area of coverage of the sprinkler.
The requirements of 8.8.4.1.1.1 shall not apply where ceiling-type sprinklers (concealed, recessed, and flush types) have the operating element above the ceiling and the deflector located nearer to the ceiling where installed in accordance with their listing.
The requirements of 8.8.4.1.1.1 shall not apply where sprinklers are listed for use under other ceiling construction features or for different distances where they shall be permitted to be installed in accordance with their listing.
The requirements of 8.8.4.1.1.1 shall not apply for light and ordinary hazard occupancies with ceilings of noncombustible or limited-combustible construction.
Where a vertical change in ceiling elevation within the area of coverage of the sprinkler creates a distance of more than 36 in. (900 mm) between the upper ceiling and the sprinkler deflector, a vertical plane extending down from the ceiling at the change in elevation shall be considered a wall for the purpose of sprinkler spacing.
Where the distance between the upper ceiling and the sprinkler deflector is less than or equal to 36 in. (900 mm), the sprinklers shall be permitted to be spaced as though the ceiling were flat, provided the obstruction rules are observed.
Under obstructed construction, the sprinkler deflector shall be located in accordance with one of the following arrangements:
  1. Installed with the deflectors within the horizontal planes of 1 in. to 6 in. (25 mm to 150 mm) below noncombustible structural members and a maximum distance of 22 in. (550 mm) below the ceiling/roof deck
  2. Installed with the deflectors at or above the bottom of noncombustible structural member to a maximum of 22 in. (550 mm) below the noncombustible ceiling/roof deck where the sprinkler is installed in conformance with 8.8.5.1.2
  3. Installed in each bay of combustible or noncombustible obstructed construction, with the deflectors located a minimum of 1 in. (25 mm) and a maximum of 12 in. (300 mm) below the ceiling
  4. Installed in accordance with their listing where sprinklers are listed for use under other ceiling construction features or for different distances
Sprinklers under or near the peak of a roof or ceiling shall have deflectors located not more than 3 ft (900 mm) vertically down from the peak in accordance with Figure 8.6.4.1.3.1(a) and Figure 8.6.4.1.3.1(b).
Deflectors of sprinklers shall be aligned parallel to ceilings or roofs.
Roofs and ceilings having a pitch not exceeding 2 in 12 (16.7 percent) are considered horizontal in the application of 8.8.4.2, and sprinklers shall be permitted to be installed with deflectors horizontal.
Sprinklers shall be located so as to minimize obstructions to discharge as defined in 8.8.5.2 and 8.8.5.3, or additional sprinklers shall be provided to ensure adequate coverage of the hazard.
Sprinklers shall be arranged to comply with one of the following arrangements:
  1. Sprinklers shall be in accordance with 8.5.5.2, Table 8.8.5.1.2, and Figure 8.8.5.1.2(a).
  2. Sprinklers shall be permitted to be spaced on opposite sides of obstructions not exceeding 4 ft (1.2 m) in width provided the distance from the centerline of the obstruction to the sprinklers does not exceed one-half the allowable distance permitted between sprinklers.
  3. Obstructions located against the wall and that are not over 30 in. (750 mm) in width shall be permitted to be protected in accordance with Figure 8.8.5.1.2(b).
  4. Obstructions located against the wall and that are not over 24 in. (600 mm) in width shall be permitted to be protected in accordance with Figure 8.8.5.1.2(c). The maximum distance between the sprinkler and the wall shall be measured from the sprinkler to the wall behind the obstruction and not to the face of the obstruction.
Table 8.8.5.1.2 Position of Sprinklers to Avoid Obstructions to Discharge (Extended Coverage Upright and Pendent Spray Sprinklers)
Distance from Sprinklers to Side of Obstruction (A) Maximum Allowable Distance of Deflector Above Bottom of Obstruction (B)
[in. (mm)]
Less than 1 ft (300 m) 0 (0)
1 ft (300 m) to less than 1 ft 6 in. (450 m) 0 (0)
1 ft 6 in. (450 m) to less than 2 ft (600 m) 1 (25)
2 ft (600 m) to less than 2 ft 6 in. (750 m) 1 (25)
2 ft 6 in. (750 m) to less than 3 ft (900 m) 1 (25)
3 ft (900 m) to less than 3 ft 6 in. (1.1 m) 3 (75)
3 ft 6 in. (1.1 m) to less than 4 ft (1.2 m) 3 (75)
4 ft (1.2 m) to less than 4 ft 6 in. (1.4 m) 5 (125)
4 ft 6 in. (1.4 m) to less than 5 ft (1.5 m) 7 (175)
5 ft (1.5 m) to less than 5 ft 6 in. (1.7 m) 7 (175)
5 ft 6 in. (1.7 m) to less than 6 ft (1.8 m) 7 (175)
6 ft (1.8 m) to less than 6 ft 6 in. (2 m) 9 (225)
6 ft 6 in. (2 m) to less than 7 ft (2.1 m) 11 (275)
7 ft (2.1 m) to less than 7 ft 6 in. (2.3 m) 14 (350)
7 ft 6 in. (2.3 m) to less than 8 ft (2.4 m) 14 (350)
8 ft (2.4 m) to less than 8 ft 6 in. (2.6 m) 15 (375)
8 ft 6 in. (2.6 m) to less than 9 ft (2.7 m) 17 (425)
9 ft (2.7 m) to less than 9 ft 6 in. (2.9 m) 19 (475)
9 ft 6 in. (2.9 m) to less than 10 ft (3.0 m) 21 (525)
Note: For A and B, refer to Figure 8.8.5.1.2(a).
FIGURE 8.8.5.1.2(a) Position of Sprinkler to Avoid Obstruction to Discharge (Extended Coverage Upright and Pendent Spray Sprinklers).
FIGURE 8.8.5.1.2(b) Obstructions Against Walls (Extended Coverage Upright and Pendent Spray Sprinklers).
FIGURE 8.8.5.1.2(c) Obstructions Against Walls (Extended Coverage Upright and Pendent Spray Sprinklers).
Continuous or noncontinuous obstructions less than or equal to 18 in. (450 mm) below the sprinkler deflector that prevent the pattern from fully developing shall comply with 8.8.5.2.
Regardless of the rules of this section, solid continuous obstructions shall meet the applicable requirements of 8.8.5.1.2.
Unless the requirements of 8.8.5.2.1.4 through 8.8.5.2.1.8 are met, sprinklers shall be positioned away from obstructions a minimum distance of four times the maximum dimension of the obstruction (e.g., truss webs and chords, pipe, columns, and fixtures) in accordance with Figure 8.8.5.2.1.3(a) and Figure 8.8.5.2.1.3(b).
A ≥ 4C or 4D
(Use dimension C or D, whichever is greater)
FIGURE 8.8.5.2.1.3(a) Minimum Distance from an Obstruction in the Vertical Orientation (Extended Coverage Upright and Pendent Spray Sprinkler).
A ≥ 4C or 4D
A ≤ 36 in. (900 mm)
(Use dimension C or D, whichever is greater)
FIGURE 8.8.5.2.1.3(b) Minimum Distance from an Obstruction in the Horizontal Orientation (Extended Coverage Upright and Pendent Spray Sprinkler).
The maximum clear distance required to obstructions in the horizontal orientation (e.g., light fixtures and truss chords) shall be 36 in. (900 mm).
The maximum clear distance shall not be applied to obstructions in the vertical orientation (e.g., columns).
Sprinklers shall be permitted to be spaced on opposite sides of the obstruction where the distance from the centerline of the obstruction to the sprinklers does not exceed one-half the allowable distance between sprinklers.
Sprinklers shall be permitted to be located one-half the distance between the obstructions where the obstruction consists of wood bar joists 20 in. (500 mm) or greater apart, provided that the top and bottom chords of the wood bar joist are not greater than 4 in. (100 mm) (nominal) in width and bar members do not exceed 1 in. (25 mm) in width.
Sprinklers shall be permitted to be installed on the centerline of a truss or bar joist or directly above a beam, provided that the truss chord or beam, dimension is not more than 8 in. (200 mm) and the sprinkler deflector is located at least 6 in. (150 mm) above the structural member and where the sprinkler is positioned at a distance four times greater than the maximum dimension of the web members away from the web members.
The requirements of 8.8.5.2.1.3 shall not apply to sprinkler system piping less than 3 in. (80 mm) in diameter.
The requirements of 8.8.5.2.1.3 shall not apply to sprinklers positioned with respect to obstructions in accordance with 8.8.5.1.2.
Sprinklers shall be permitted to be placed without regard to the blades of ceiling fans less than 60 in. (1.5 m) in diameter, provided the plan view of the fan is at least 50 percent open.
The distance from sprinklers to privacy curtains, freestanding partitions, room dividers, and similar obstructions in light hazard occupancies shall be in accordance with Table 8.8.5.2.2 and Figure 8.8.5.2.2.
Table 8.8.5.2.2 Suspended or Floor-Mounted Obstructions (Extended Coverage Upright and Pendent Spray Sprinklers) in Light Hazard Occupancies Only
Horizontal Distance (A) Minimum Vertical Distance Below Deflector (B) [in. (mm)]
6 in. (150 mm) or less 3 (75)
More than 6 in. (150 mm) to 9 in. (225 mm) 4 (100)
More than 9 in. (225 mm) to 12 in. (300 mm) 6 (150)
More than 12 in. (300 mm) to 15 in. (375 mm) 8 (200)
More than 15 in. (375 mm) to 18 in. (450 mm) 91/2 (240)
More than 18 in. (450 mm) to 24 in. (600 mm) 121/2 (315)
More than 24 in. (600 mm) to 30 in. (750 mm) 151/2 (390)
More than 30 in. (750 mm) 18 (450)
Note: For A and B, refer to Figure 8.8.5.2.2.
FIGURE 8.8.5.2.2 Suspended or Floor-Mounted Obstruction (Extended Coverage Upright and Pendent Spray Sprinklers) in Light Hazard Occupancy Only.
In light hazard occupancies, privacy curtains, as shown in Figure 8.8.5.2.2, shall not be considered obstructions where all of the following are met:
  1. The curtains are supported by fabric mesh on ceiling track.
  2. Openings in the mesh are equal to 70 percent or greater.
  3. The mesh extends a minimum of 22 in. (550 mm) down from ceiling.
Continuous or noncontinuous obstructions that interrupt the water discharge in a horizontal plane more than 18 in. (450 mm) below the sprinkler deflector in a manner to limit the distribution from reaching the protected hazard shall comply with 8.8.5.3.
Sprinklers shall be installed under fixed obstructions over 4 ft (1.2 m) wide such as ducts, decks, open grate flooring, cutting tables, and overhead doors.
Sprinklers shall not be required under obstructions that are not fixed in place such as conference tables.
Sprinklers installed under open gratings shall be of the intermediate level/rack storage type or otherwise shielded from the discharge of overhead sprinklers.
The deflector of automatic sprinklers installed under fixed obstructions shall be positioned no more than 12 in. (300 mm) below the bottom of the obstruction.
Sprinklers installed under round ducts shall be of the intermediate level/rack storage type or otherwise shielded from the discharge of overhead sprinklers.
The clearance between the deflector and the top of storage shall be 18 in. (450 mm) or greater.
Where other standards specify greater clearance to storage minimums, they shall be followed.
Except as provided in 8.8.7.2 and 8.8.7.3, sprinklers shall be required in all ceiling pockets.
Sprinklers shall not be required in ceiling pockets where all of the following are met:
  1. The total volume of the unprotected ceiling pocket does not exceed 1000 ft3 (28 m3).
  2. The depth of the unprotected ceiling pocket does not exceed 36 in. (900 mm).
  3. The entire floor under the unprotected ceiling pocket is protected by sprinklers at the lower ceiling elevation.
  4. *The total size of all unprotected ceiling pockets in the same compartment within 10 ft (3 m) of each other does not exceed 1000 ft3 (28 m3).
  5. The unprotected ceiling pocket has noncombustible or limited-combustible finishes.
  6. Quick-response sprinklers are utilized throughout the compartment.
Sprinklers shall not be required in skylights and similar pockets in accordance with 8.5.7.
All requirements of Section 8.5 shall apply to extended coverage sidewall spray sprinklers except as modified in Section 8.9.
The protection area of coverage per sprinkler (As) for extended coverage sidewall sprinklers shall be not less than that prescribed by the listing.
Listing dimensions shall be in 2 ft (600 mm) increments up to 28 ft (8.5 m).
The maximum allowable protection area of coverage for a sprinkler (As) shall be in accordance with the value indicated in Table 8.9.2.2.1.
Table 8.9.2.2.1 Protection Area and Maximum Spacing for Extended Coverage Sidewall Spray Sprinklers
Construction Type Light Hazard Ordinary Hazard
Protection Area Spacing Protection Area Spacing
ft2 m2 ft m ft2 m2 ft m
Unobstructed, smooth, flat 400 37 28 8.5 400 37 24 7.3
In any case, the maximum area of coverage of a sprinkler shall not exceed 400 ft2 (37.2 m2).
The maximum distance permitted between sprinklers shall be based on the centerline distance between sprinklers on the branch line along the wall.
Where sprinklers are installed along the length of a single wall of rooms or bays, they shall be spaced in accordance with the maximum spacing provisions of Table 8.9.2.2.1.
Sidewall sprinklers shall not be installed back-to-back without being separated by a continuous lintel, soffit, or baffle.
Sidewall sprinklers shall be permitted to be installed on opposing or adjacent walls, provided no sprinkler is located within the maximum protection area of another sprinkler.
The distance from sprinklers to the end walls shall not exceed one-half of the allowable distance permitted between sprinklers as indicated in Table 8.9.2.2.1.
Sprinklers shall be located a minimum of 4 in. (100 mm) from an end wall.
The distance from the wall to the sprinkler shall be measured perpendicular to the wall.
Sprinklers shall be not located within the maximum protection area of any other sprinkler unless required by 8.9.4.1.4.1 or separated by baffles that comply with the following:
  1. Baffles shall be arranged to protect the actuating elements.
  2. Baffles shall be of solid and rigid material that will stay in place before and during sprinkler operation.
  3. Baffles shall be not less than 8 in. (200 mm) long and 6 in. (150 mm) high.
  4. The tops of baffles shall extend between 2 in. and 3 in. (50 mm and 75 mm) above the deflectors.
  5. The bottoms of baffles shall extend downward to a level at least even with the deflectors.
Unless the requirements of 8.9.4.1.1.2 are met, sidewall sprinkler deflectors shall be located not more than 6 in. (150 mm) nor less than 4 in. (100 mm) from ceilings.
Horizontal sidewall sprinklers shall be permitted to be located in a zone 6 in. to 12 in. (150 mm to 300 mm) or 12 in. to 18 in. (300 mm to 450 mm) below noncombustible or limited-combustible ceilings where listed for such use.
Sidewall sprinkler deflectors shall be located not more than 6 in. (150 mm) or less than 4 in. (100 mm) from walls on which they are mounted.
Horizontal sidewall sprinklers shall be permitted to be located with their deflectors less than 4 in. (100 mm) from the wall on which they are mounted.
Where soffits used for the installation of sidewall sprinklers are less than or equal to 8 in. (200 mm) in width or projection from the wall, additional sprinklers shall not be required below the soffit.
A sidewall sprinkler shall be permitted to be installed under a soffit when both the minimum distance from the sprinkler deflector to the bottom of the soffit and the maximum distance from the sprinkler deflector to the high ceiling are maintained.
Soffits and Cabinets in Residential Areas/Occupancies. Where soffits are used for the installation of sidewall sprinklers, the sprinklers and soffits shall be installed in accordance with 8.9.4.1.4.1, 8.9.4.1.4.2, or 8.9.4.1.4.3.
Where soffits exceed more than 8 in. (200 mm) in width or projection from the wall, pendent sprinklers shall be installed under the soffit.
Sidewall sprinklers shall be permitted to be installed in the face of a soffit located directly over cabinets, without requiring additional sprinklers below the soffit or cabinets, where the soffit does not project horizontally more than 12 in. (300 mm) from the wall.
Where sidewall sprinklers are more than 3 ft (900 mm) above the top of cabinets, the sprinkler shall be permitted to be installed on the wall above the cabinets where the cabinets are no greater than 12 in. (300 mm) from the wall.
Deflectors of sprinklers shall be aligned parallel to ceilings or roofs.
Sidewall sprinklers, where installed under a sloped ceiling with a slope exceeding 2 in 12, shall be located at the high point of the slope and positioned to discharge downward along the slope.
Sidewall sprinklers specifically listed for other ceiling configurations shall be permitted to be installed in accordance with the listing requirements.
Sprinklers shall be located so as to minimize obstructions to discharge as defined in 8.5.5.2 and 8.5.5.3, or additional sprinklers shall be provided to ensure adequate coverage of the hazard.
Sidewall sprinklers shall be installed no closer than 8 ft (2.4 m) from light fixtures or similar obstructions.
The distance between light fixtures or similar obstructions located more than 8 ft (2.4 m) from the sprinkler shall be in conformance with Table 8.9.5.1.3 and Figure 8.9.5.1.3.
Table 8.9.5.1.3 Positioning of Sprinklers to Avoid Obstructions (Extended Coverage Sidewall Spray Sprinklers)
Distance from Sidewall Sprinkler to Side of Obstruction (A) Maximum Allowable Distance of Deflector Above Bottom of Obstruction (B) [in. (mm)]
Less than 8 ft (2.4 m) Not allowed
8 ft (2.4 m) to less than 10 ft (3.0 m) 1 (25)
10 ft (3.0 m) to less than 11 ft (3.3 m) 2 (50)
11 ft (3.3 m) to less than 12 ft (3.7 m) 3 (75)
12 ft (3.7 m) to less than 13 ft (4.0 m) 4 (100)
13 ft (4.0 m) to less than 14 ft (4.3 m) 6 (150)
14 ft (4.3 m) to less than 15 ft (4.6 m) 7 (175)
15 ft (4.6 m) to less than 16 ft (4.9 m) 9 (225)
16 ft (4.9 m) to less than 17 ft (5.2 m) 11 (275)
17 ft (5.2 m) or greater 14 (350)
Note: For A and B, refer to Figure 8.9.5.1.3.
FIGURE 8.9.5.1.3 Positioning of Sprinkler to Avoid Obstruction (Extended Coverage Sidewall Spray Sprinklers).
Continuous obstructions projecting from the same wall as the one on which the sidewall sprinkler is mounted shall be in accordance with one of the following arrangements:
  1. Sprinklers shall be installed in accordance with Table 8.9.5.1.4 and Figure 8.9.5.1.4(a).
  2. Sprinklers shall be permitted to be spaced on opposite sides of obstructions less than 4 ft (1.2 m) in width where the distance from the centerline of the obstruction to the sprinklers does not exceed one-half the allowable distance between sprinklers.
  3. Obstructions located against the wall and that are not over 30 in. (750 mm) in width shall be permitted to be protected in accordance with Figure 8.9.5.1.4(b).
  4. Obstructions located against the wall and that are not over 24 in. (600 mm) in width shall be permitted to be protected in accordance with Figure 8.9.5.1.4(c). The maximum distance between the sprinkler and the wall shall be measured from the sprinkler to the wall behind the obstruction and not to the face of the obstruction.
Table 8.9.5.1.4 Positioning of Sprinklers to Avoid Obstructions Along Wall (Extended Coverage Sidewall Spray Sprinklers)
Distance from Sidewall Sprinkler to Side of Obstruction (A) Maximum Allowable Distance of Deflector Above Bottom of Obstruction (B)
[in. (mm)]
Less than 1 ft 6 in. (450 mm) 0 (0)
1 ft 6 in. (450 mm) to less than 3 ft (900 mm) 1 (25)
3 ft (900 mm) to less than 4 ft (1.2 m) 3 (75)
4 ft (1.2 m) to less than 4 ft 6 in. (1.4 m) 5 (125)
4 ft 6 in. (1.4 m) to less than 6 ft (1.5 m) 7 (175)
6 ft (1.5 m) to less than 6 ft 6 in. (2.0 m) 9 (225)
6 ft 6 in. (2.0 m) to less than 7 ft (2.1 m) 11 (275)
7 ft (2.1 m) to less than 7 ft 6 in. (2.3 m) 14 (350)
Note: For A and B, refer to Figure 8.9.5.1.4(a).
FIGURE 8.9.5.1.4(a) Positioning of Sprinkler to Avoid Obstruction Along Wall (Extended Coverage Sidewall Spray Sprinklers).
FIGURE 8.9.5.1.4(b) Obstruction Against Wall (Extended Coverage Sidewall Spray Sprinklers).
FIGURE 8.9.5.1.4(c) Obstruction Against Wall (Extended Coverage Sidewall Spray Sprinklers).
Isolated obstructions projecting from the same wall as the one on which the extended coverage sidewall sprinkler is mounted shall be located a minimum of 6 in. (150 mm) from the sidewall sprinkler.
Obstructions on the wall opposite from the sidewall sprinkler shall be permitted where the obstruction is up to 2 ft (600 mm) deep and 2 ft (600 mm) wide.
Continuous or noncontinuous obstructions less than or equal to 18 in. (450 mm) below the sprinkler deflector that prevent the pattern from fully developing shall comply with this section.
Regardless of the rules of this section, solid continuous obstructions shall meet the requirements of 8.9.5.1.2 and 8.9.5.1.3.
Unless the requirements of 8.9.5.2.1.4 through 8.9.5.2.1.5 are met, sprinklers shall be positioned away from obstructions a minimum distance of four times the maximum dimension of the obstruction (e.g., truss webs and chords, pipe, columns, and fixtures) in accordance with Figure 8.9.5.2.1.3(a) and Figure 8.9.5.2.1.3(b).
A ≥ 4C or 4D
(Use dimension C or D, whichever is greater)
FIGURE 8.9.5.2.1.3(a) Minimum Distance from an Obstruction in the Vertical Orientation (Extended Coverage Sidewall).
A ≥ 4C or 4D
A ≤ 36 in. (900 mm)
(Use dimension C or D, whichever is greater)
FIGURE 8.9.5.2.1.3(b) Minimum Distance from an Obstruction in the Horizontal Orientation (Extended Coverage Sidewall).
The maximum clear distance required to obstructions in the horizontal orientation (e.g., light fixtures and truss chords), shall be 36 in. (900 mm).
The maximum clear distance shall not be applied to obstructions in the vertical orientation (e.g., columns).
The requirements of 8.9.5.2.1.3 and 8.9.5.2.1.4 shall not apply where sprinklers are positioned with respect to obstructions in accordance with 8.9.5.1.2 and 8.9.5.1.3.
The requirements of 8.9.5.2.1.3 shall not apply to sprinkler system piping less than 3 in. (80 mm) in diameter.
Sprinklers shall be permitted to be placed without regard to the blades of ceiling fans less than 60 in. (1.5 m) in diameter, provided the plan view of the fan is at least 50 percent open.
The distance from sprinklers to privacy curtains, freestanding partitions, room dividers, and similar obstructions in light hazard occupancies shall be in accordance with Table 8.9.5.2.2 and Figure 8.9.5.2.2.
Table 8.9.5.2.2 Suspended or Floor-Mounted Obstructions (Extended Coverage Sidewall Sprinklers) in Light Hazard Occupancies Only
Horizontal Distance (A) Minimum Allowable Distance Below Deflector (B) [in. (mm)]
6 in. (150 mm) or less 3 (75)
More than 6 in. (150 mm) to 9 in. (225 mm) 4 (100)
More than 9 in. (225 mm) to 12 in. (300 mm) 6 (150)
More than 12 in. (300 mm) to 15 in. (375 mm) 8 (200)
More than 15 in. (375 mm) to 18 in. (450 mm) 91/2 (240)
More than 18 in. (450 mm) to 24 in. (600 mm) 121/2 (315)
More than 24 in. (600 mm) to 30 in. (750 mm) 151/2 (390)
More than 30 in. (750 mm) 18 (450)
Note: For A and B, refer to Figure 8.9.5.2.2.
FIGURE 8.9.5.2.2 Suspended or Floor-Mounted Obstruction (Extended Coverage Sidewall Sprinklers) in Light Hazard Occupancy Only.
In light hazard occupancies, privacy curtains, as shown in Figure 8.9.5.2.2, shall not be considered obstructions where all of the following are met:
  1. The curtains are supported by fabric mesh on ceiling track.
  2. Openings in the mesh are equal to 70 percent or greater.
  3. The mesh extends a minimum of 22 in. (550 mm) down from ceiling.
Continuous or noncontinuous obstructions that interrupt the water discharge in a horizontal plane more than 18 in. (450 mm) below the sprinkler deflector in a manner to limit the distribution from reaching the protected hazard shall comply with this section.
Sprinklers shall be installed under fixed obstructions over 4 ft (1.2 m) wide, such as ducts, decks, open grate flooring, cutting tables, and overhead doors.
Sprinklers shall not be required under obstructions that are not fixed in place, such as conference tables.
Areas of coverage shall be in accordance with the manufacturer's listing.
Residential sprinklers shall not be permitted to be used on ceilings with slopes greater than 8 in 12 or ceiling with heights greater than 24 ft unless specifically listed for this purpose.
Maximum distances between sprinklers shall be in accordance with the manufacturer's listing.
The distance between the sprinkler and the wall shall not exceed half the maximum allowable distance between sprinklers per the manufacturer's listing.
The minimum distance between sprinklers within a compartment shall be 8 ft (2.4 m), unless the listing of the sprinkler requires a greater distance, unless required by 8.10.7.1.5.1, or unless separated by baffles that comply with the following:
  1. Baffles shall be arranged to protect the actuating elements.
  2. Baffles shall be of solid and rigid material that will stay in place before and during sprinkler operation.
  3. Baffles shall be not less than 8 in. (200 mm) long and 6 in. (150 mm) high.
  4. The tops of baffles shall extend between 2 in. and 3 in. (50 mm and 75 mm) above the deflectors of upright sprinklers.
  5. The bottoms of baffles shall extend downward to a level at least even with the deflectors of pendent sprinklers.
Residential sidewall sprinklers shall be permitted to be installed on opposing or adjacent walls, provided no sprinkler is located within the maximum protection area of another sprinkler or unless separated by baffles that comply with the following:
  1. Baffles shall be arranged to protect the actuating elements.
  2. Baffles shall be of solid and rigid material that will stay in place before and during sprinkler operation.
  3. Baffles shall be not less than 8 in. (200 mm) long and 6 in. (150 mm) high.
  4. The tops of baffles shall extend between 2 in. and 3 in. (50 mm and 75 mm) above the deflectors.
  5. The bottoms of baffles shall extend downward to a level at least even with the deflectors.
The maximum distance shall be measured along the slope of the ceiling as shown in Figure 8.10.3.5(a) and Figure 8.10.3.5(b).
FIGURE 8.10.3.5(a) Maximum Distance Between Sprinklers with Sloped Ceilings — Arrangement A.
FIGURE 8.10.3.5(b) Maximum Distance Between Sprinklers with Sloped Ceilings — Arrangement B.
Where sprinklers are installed along sloped ceilings, the sprinklers shall maintain the minimum listed spacing, but no less than 8 ft (2.4 m), measured in the plan view from one sprinkler to another as shown in Figure 8.10.3.6(a) and Figure 8.10.3.6(b), or unless separated by baffles that comply with the following:
  1. Baffles shall be arranged to protect the actuating elements.
  2. Baffles shall be of solid and rigid material that will stay in place before and during sprinkler operation.
  3. Baffles shall be not less than 8 in. (200 mm) long and 6 in. (150 mm) high.
  4. The tops of baffles shall extend between 2 in. and 3 in. (50 mm and 75 mm) above the deflectors of upright sprinklers.
  5. The bottoms of baffles shall extend downward to a level at least even with the deflectors of pendent sprinklers.
FIGURE 8.10.3.6(a) Minimum Distance Between Sprinklers with Sloped Ceilings — Arrangement A.
FIGURE 8.10.3.6(b) Minimum Distance Between Sprinklers with Sloped Ceilings —Arrangement B.
Pendent and upright sprinklers shall be positioned so that the deflectors are 1 in. to 4 in. (25 mm to 100 mm) from the ceiling unless the listing allows a greater distance.
Sidewall sprinklers shall be positioned so that the deflectors are within 4 in. to 6 in. (100 mm to 150 mm) from the ceiling unless the listing allows greater distances.
Where soffits used for the installation of sidewall sprinklers exceed 8 in. (200 mm) in width or projection from the wall, additional sprinklers shall be installed below the soffit.
Residential horizontal sidewall sprinkler deflectors shall be located no more than 6 in. (150 mm) from the wall on which they are mounted unless listed for greater distances.
The distance from sprinklers to the end walls shall not exceed one-half of the allowable distance permitted between sprinklers as indicated in the sprinkler listing.
Sprinklers shall be located a minimum of 4 in. (100 mm) from an end wall.
The distance from the wall to the sprinkler shall be measured perpendicular to the wall.
Deflector Orientation (Residential Upright and Pendent Spray).
Unless the requirements of 8.10.4.7.2 or 8.10.4.7.3 are met, deflectors of upright and pendent sprinklers shall be aligned parallel to ceilings, roofs, or the incline of stairs.
Where upright or pendent sprinklers are installed at the peak below a sloped ceiling or roof surface, the sprinkler shall be installed with the deflector horizontal.
Roofs and ceilings having a pitch not exceeding 2 in 12 (16.7 percent) are considered horizontal in the application of 8.10.4.7, and upright and pendent sprinklers shall be permitted to be installed with deflectors horizontal.
Residential sprinklers installed in conformance with this standard shall follow the sprinkler obstruction rules of 8.10.6 or 8.10.7 as appropriate for their installation orientation (upright, pendent, or sidewall) and the obstruction criteria specified in the manufacturer's installation instructions.
Sprinklers shall be located so as to minimize obstructions to discharge as defined in 8.10.6.2 and 8.10.6.3, or additional sprinklers shall be provided to ensure adequate coverage of the hazard.
Sprinklers shall be arranged to comply with one of the following arrangements:
  1. Sprinklers shall be in accordance with 8.5.5.2, Table 8.10.6.1.2, and Figure 8.10.6.1.2(a).
  2. Sprinklers shall be permitted to be spaced on opposite sides of obstructions not exceeding 4 ft (1.2 m) in width, provided the distance from the centerline of the obstruction to the sprinklers does not exceed one-half the allowable distance permitted between sprinklers.
  3. Obstructions located against the wall and that are not over 30 in. (750 mm) in width shall be permitted to be protected in accordance with Figure 8.10.6.1.2(b).
  4. Obstructions that are located against the wall and that are not over 24 in. (600 mm) in width shall be permitted to be protected in accordance with Figure 8.10.6.1.2(c). The maximum distance between the sprinkler and the wall shall be measured from the sprinkler to the wall behind the obstruction and not to the face of the obstruction.
Table 8.10.6.1.2 Positioning of Sprinklers to Avoid Obstructions to Discharge (Residential Upright and Pendent Spray Sprinklers)
Distance from Sprinklers to Side of Obstruction (A) Maximum Allowable Distance of Deflector Above Bottom of Obstruction (B)
[in. (mm)]
Less than 1 ft (300 mm) 0 (0)
1 ft (300 mm) to less than 1 ft 6 in. (450 mm) 0 (0)
1 ft 6 in. (450 mm) to less than 2 ft (600 mm) 1 (25)
2 ft (600 mm) to less than 2 ft 6 in. (750 mm) 1 (25)
2 ft 6 in. (750 mm) to less than 3 ft (900 mm) 1 (25)
3 ft (900 mm) to less than 3 ft 6 in. (1.1 m) 3 (75)
3 ft 6 in. (1.1 m) to less than 4 ft (1.2 m) 3 (75)
4 ft (1.2 m) to less than 4 ft 6 in. (1.4 m) 5 (125)
4 ft 6 in. (1.4 m) to less than 5 ft (1.5 m) 7 (175)
5 ft (1.5 m) to less than 5 ft 6 in. (1.7 m) 7 (175)
5 ft 6 in. (1.7 m) to less than 6 ft (1.8 m) 7 (175)
6 ft (1.8 m) to less than 6 ft 6 in. (2.0 m) 9 (225)
6 ft 6 in. (2.0 m) to less than 7 ft (2.1 m) 11 (275)
7 ft (2.1 m) and greater 14 (350)
Note: For A and B, refer to Figure 8.10.6.1.2(a).
FIGURE 8.10.6.1.2(a) Positioning of Sprinkler to Avoid Obstruction to Discharge (Residential Upright and Pendent Spray Sprinklers).
FIGURE 8.10.6.1.2(b) Obstructions Against Wall (Residential Upright and Pendent Spray Sprinklers).
FIGURE 8.10.6.1.2(c) Obstructions Against Wall (Measurements for Residential Upright and Pendent Spray Sprinklers).
Continuous or noncontinuous obstructions less than or equal to 18 in. (450 mm) below the sprinkler deflector that prevent the pattern from fully developing shall comply with 8.10.6.2.
Regardless of the rules of this section, solid continuous obstructions shall meet the applicable requirements of 8.10.6.1.2.
Unless the requirements of 8.10.6.2.1.4 through 8.10.6.2.1.8 are met, sprinklers shall be positioned away from obstructions a minimum distance of four times the maximum dimension of the obstruction (e.g., truss webs and chords, pipe, columns, and fixtures) in accordance with Figure 8.10.6.2.1.3(a) and Figure 8.10.6.2.1.3(b).
A ≥ 4C or 4D
(Use dimension C or D, whichever is greater)
FIGURE 8.10.6.2.1.3(a) Minimum Distance from an Obstruction in the Vertical Orientation (Residential Upright and Pendent Spray Sprinkler).
A ≥ 4C or 4D
A ≤ 36 in. (900 mm)
(Use dimension C or D, whichever is greater)
FIGURE 8.10.6.2.1.3(b) Minimum Distance from an Obstruction in the Horizontal Orientation (Residential Upright and Pendent Spray Sprinkler).
The maximum clear distance required to obstructions in the horizontal orientation (e.g., light fixture and truss chords) shall be 36 in. (900 mm).
The maximum clear distance shall not be applied to obstructions in the vertical orientation (e.g., columns).
Sprinklers shall be permitted to be spaced on opposite sides of the obstruction where the distance from the centerline of the obstruction to the sprinklers does not exceed one-half the allowable distance between sprinklers.
Sprinklers shall be permitted to be located one-half the distance between the obstructions where the obstruction consists of open trusses 20 in. (500 mm) or greater apart [24 in. (600 mm) on center], provided that all truss members are not greater than 4 in. (100 mm) (nominal) in width and web members do not exceed 1 in. (25 mm) in width.
Sprinklers shall be permitted to be installed on the centerline of a truss or bar joist or directly above a beam provided that the truss chord or beam dimension is not more than 8 in. (200 mm) and the sprinkler deflector is located at least 6 in. (150 mm) above the structural member and where the sprinkler is positioned at a distance four times greater than the maximum dimension of the web members away from the web members.
The requirements of 8.10.6.2.1.3 shall not apply to sprinkler system piping less than 3 in. (80 mm) in diameter.
The requirements of 8.10.6.2.1.3 shall not apply to sprinklers positioned with respect to obstructions in accordance with 8.10.6.1.2.
Sprinklers shall be permitted to be placed without regard to the blades of a ceiling fan, provided the plan view of the fan is at least 50 percent open.
The distance from sprinklers to privacy curtains, freestanding partitions, room dividers, and similar obstructions in light hazard occupancies shall be in accordance with Table 8.10.6.2.2 and Figure 8.10.6.2.2.
Table 8.10.6.2.2 Suspended or Floor-Mounted Obstructions (Residential Upright and Pendent Spray Sprinklers) in Light Hazard Occupancies Only
Horizontal Distance (A) Minimum Vertical Distance Below Deflector (B)
[in. (mm)]
6 in. (150 mm) or less 3 (75)
More than 6 in. (150 mm) to 9 in. (225 mm) 4 (100)
More than 9 in. (225 mm) to 12 in. (300 mm) 6 (150)
More than 12 in. (300 mm) to 15 in. (375 mm) 8 (200)
More than 15 in. (375 mm) to 18 in. (450 mm) 91/2 (240)
More than 18 in. (450 mm) to 24 in. (600 mm) 121/2 (315)
More than 24 in. (600 mm) to 30 in. (750 mm) 151/2 (390)
More than 30 in. (750 mm) 18 (450)
Note: For A and B, refer to Figure 8.10.6.2.2.
FIGURE 8.10.6.2.2 Suspended or Floor-Mounted Obstruction (Residential Upright and Pendent Spray Sprinklers) in Light Hazard Occupancy Only.
Continuous or noncontinuous obstructions that interrupt the water discharge in a horizontal plane more than 18 in. (450 mm) below the sprinkler deflector in a manner to limit the distribution from reaching the protected hazard shall comply with 8.10.6.3.
Sprinklers shall be installed under fixed obstructions over 4 ft (1.2 m) wide such as stairs and landings.
Sprinklers shall not be required under obstructions that are not fixed in place.
Sprinklers installed under open gratings shall be shielded from the discharge of overhead sprinklers.
Sprinklers shall be located so as to minimize obstructions to discharge as defined in 8.5.5.2 and 8.5.5.3, or additional sprinklers shall be provided to ensure adequate coverage of the hazard.
Sidewall sprinklers shall be installed no closer than 8 ft (2.4 m) from light fixtures or similar obstructions.
The distance between light fixtures or similar obstructions located more than 8 ft (2.4 m) from the sprinkler shall be in conformance with Table 8.10.7.1.3 and Figure 8.10.7.1.3.
Table 8.10.7.1.3 Positioning of Sprinklers to Avoid Obstructions (Residential Sidewall Sprinklers)
Distance from Sidewall Sprinkler to Side of Obstruction (A) Maximum Allowable Distance of Deflector Above Bottom of Obstruction (B)
[in. (mm)]
Less than 8 ft (2.4 m) Not allowed
8 ft (2.4 m) to less than 10 ft (3.0 m) 1 (25)
10 ft (3.0 m) to less than 11 ft (3.3 m) 2 (50)
11 ft (3.3 m) to less than 12 ft (3.7 m) 3 (75)
12 ft (3.7 m) to less than 13 ft (4.0 m) 4 (100)
13 ft (4.0 m) to less than 14 ft (4.3 m) 6 (150)
14 ft (4.3 m) to less than 15 ft (4.6 m) 7 (175)
15 ft (4.6 m) to less than 16 ft (4.9 m) 9 (225)
16 ft (4.9 m)to less than 17 ft (5.2 m) 11 (275)
17 ft (5.2 m) or greater 14 (350)
Note: For A and B, refer to Figure 8.10.7.1.3.
FIGURE 8.10.7.1.3 Positioning of Sprinkler to Avoid Obstruction (Residential Sidewall Sprinklers).
Continuous obstructions projecting from the same wall as the one on which the sidewall sprinkler is mounted shall be in accordance with one of the following arrangements:
  1. Sprinklers shall be in accordance with Table 8.10.7.1.4 and Figure 8.10.7.1.4(a).
  2. Sprinklers shall be permitted to be spaced on opposite sides of obstructions less than 4 ft (1.2 m) in width where the distance from the centerline of the obstruction to the sprinklers does not exceed one-half the allowable distance between sprinklers.
  3. Obstructions located against the wall and that are not over 30 in. (750 mm) in width shall be permitted to be protected in accordance with Figure 8.10.7.1.4(b).
  4. Obstructions located against the wall and that are not over 24 in. (600 mm) in width shall be permitted to be protected in accordance with Figure 8.10.7.1.4(c). The maximum distance between the sprinkler and the wall shall be measured from the sprinkler to the wall behind the obstruction and not to the face of the obstruction.
Table 8.10.7.1.4 Positioning of Sprinklers to Avoid Obstructions Along Wall (Residential Sidewall Sprinklers)
Distance from Sidewall Sprinkler to Side of Obstruction (A) Maximum Allowable Distance of Deflector Above Bottom of Obstruction (B)
[in. (mm)]
Less than 1 ft 6 in. (450 mm) 0 (0)
1 ft 6 in. (450 mm) to less than 3 ft (900 mm) 1 (25)
3 ft (900 mm) to less than 4 ft (1.2 m) 3 (75)
4 ft (1.2 m) to less than 4 ft 6 in. (1.4 m) 5 (125)
4 ft 6 in. (1.4 m) to less than 6 ft (1.8 m) 7 (175)
6 ft (1.8 m) to less than 6 ft 6 in. (2.0 m) 9 (225)
6 ft 6 in. (2.0 m) to less than 7 ft (2.1 m) 11 (275)
7 ft (2.1 m) to less than 7 ft 6 in. (2.3 m) 14 (350)
Note: For A and B, refer to Figure 8.10.7.1.4(a).
FIGURE 8.10.7.1.4(a) Positioning of Sprinkler to Avoid Obstruction Along Wall (Residential Sidewall Sprinklers).
FIGURE 8.10.7.1.4(b) Obstruction Against Wall (Residential Sidewall Spray Sprinklers).
FIGURE 8.10.7.1.4(c) Obstruction Against Wall (Residential Sidewall Spray Sprinklers).
Where soffits are used for the installation of sidewall sprinklers, the sprinklers and soffits shall be installed in accordance with 8.10.7.1.5.1, 8.10.7.1.5.2, or 8.10.7.1.5.3.
Where soffits exceed more than 8 in. (200 mm) in width or projection from the wall, pendent sprinklers shall be installed under the soffit.
Sidewall sprinklers shall be permitted to be installed in the face of a soffit located directly over cabinets, without requiring additional sprinklers below the soffit or cabinets, where the soffit does not project horizontally more than 12 in. (300 mm) from the wall.
Where sidewall sprinklers are more than 3 ft (900 mm) above the top of cabinets, the sprinkler shall be permitted to be installed on the wall above the cabinets where the cabinets are no greater than 12 in. (300 mm) from the wall.
Obstructions on the wall opposite from the sidewall sprinkler shall be permitted where the obstruction is up to 2 ft (600 mm) deep and 2 ft (600 mm) wide.
Continuous or noncontinuous obstructions less than or equal to 18 in. (450 mm) below the sprinkler deflector that prevent the pattern from fully developing shall comply with this section.
Regardless of the rules of this section, solid continuous obstructions shall meet the requirements of 8.10.7.1.2 and 8.10.7.1.3.
Unless the requirements of 8.10.7.2.1.4 through 8.10.7.2.1.7 are met, sprinklers shall be positioned away from obstructions a minimum distance of four times the maximum dimension of the obstruction (e.g., truss webs and chords, pipe, columns, and fixtures).
The maximum clear distance required from obstructions in the horizontal orientation (e.g., light fixtures and truss chords) shall be 36 in. (900 mm).
The maximum clear distance shall not be applied to obstructions in the vertical orientation (e.g., columns).
Sidewall sprinklers shall be positioned in accordance with Figure 8.10.7.2.1.4(a) and Figure 8.10.7.2.1.4(b) when obstructions are present.
A ≥ 4C or 4D
(Use dimension C or D, whichever is greater)
FIGURE 8.10.7.2.1.4(a) Minimum Distance from an Obstruction in the Vertical Orientation (Residential Sidewall Sprinkler).
A ≥ 4C or 4D
A ≤ 36 in. (900 mm)
(Use dimension C or D, whichever is greater)
FIGURE 8.10.7.2.1.4(b) Minimum Distance from an Obstruction in the Horizontal Orientation (Residential Sidewall Sprinkler).
The requirements of 8.10.7.2.1.3 and 8.10.7.2.1.4 shall not apply where sprinklers are positioned with respect to obstructions in accordance with 8.10.7.1.2 and 8.10.7.1.3.
The requirements of 8.10.7.2.1.3 shall not apply to sprinkler system piping less than 3 in. (80 mm) in diameter.
Sprinklers shall be permitted to be placed without regard to the blades of a ceiling fan, provided the plan view of the fan is at least 50 percent open.
Suspended or Floor-Mounted Vertical Obstructions. The distance from sprinklers to privacy curtains, freestanding partitions, room dividers, and similar obstructions in light hazard occupancies shall be in accordance with Table 8.10.7.2.2 and Figure 8.10.7.2.2.
Table 8.10.7.2.2 Suspended or Floor-Mounted Obstructions (Residential Sidewall Sprinklers) in Light Hazard Occupancies Only
Horizontal Distance (A) Minimum Allowable Distance Below Deflector (B)
[in. (mm)]
6 in. (150 mm) or less 3 (75)
More than 6 in. (150 mm) to 9 in. (225 mm) 4 (100)
More than 9 in. (225 mm) to 12 in. (300 mm) 6 (150)
More than 12 in. (300 mm) to 15 in. (375 mm) 8 (200)
More than 15 in. (375 mm) to 18 in. (450 mm) 91/2 (240)
More than 18 in. (450 mm) to 24 in. (600 mm) 121/2 (315)
More than 24 in. (600 mm) to 30 in. (750 mm) 151/2 (390)
More than 30 in. (750 mm) 18 (450)
For SI units, 1 in. = 25.4 mm.
Note: For A and B, refer to Figure 8.10.7.2.2.
FIGURE 8.10.7.2.2 Suspended or Floor-Mounted Obstruction (Residential Sidewall Sprinklers) in Light Hazard Occupancy Only.
Continuous or noncontinuous obstructions that interrupt the water discharge in a horizontal plane more than 18 in. (450 mm) below the sprinkler deflector in a manner to limit the distribution from reaching the protected hazard shall comply with this section.
Sprinklers shall be installed under fixed obstructions over 4 ft (1.2 m) wide, such as ducts, stairs, and landings.
Sprinklers shall not be required under obstructions that are not fixed in place.
Sprinklers installed under open gratings shall be shielded from the discharge of overhead sprinklers.
The deflector of automatic sprinklers installed under fixed obstructions shall be positioned below the bottom of the obstruction in accordance with their listed distance below ceilings.
Sprinklers installed under round ducts shall be shielded from the discharge of overhead sprinklers.
Sprinklers shall be required in all ceiling pockets.
The requirement of 8.10.8.1 shall not apply where all of the following requirements are met:
  1. The total volume of the unprotected ceiling pocket does not exceed 100 ft3 (2.8 m3).
  2. The depth of the unprotected ceiling pocket does not exceed 12 in. (300 mm).
  3. The entire floor of the unprotected ceiling pocket is protected by the sprinklers at the lower ceiling elevation.
  4. The interior finish of the unprotected ceiling pocket is noncombustible or limited-combustible construction.
All requirements of Section 8.5 shall apply to CMSA sprinklers except as modified in Section 8.11.
CMSA pendent sprinklers shall be installed in accordance with Section 8.5 and the manufacturer's installation instructions in lieu of the requirements in Section 8.11.
The protection area of coverage per sprinkler (As) shall be determined in accordance with 8.5.2.1.
The maximum allowable protection area of coverage for a sprinkler (As) shall be in accordance with the value indicated in Table 8.11.2.2.1.
Table 8.11.2.2.1 Protection Areas and Maximum Spacing for CMSA Sprinklers
Construction Type Protection Area Maximum Spacing
ft2 m2 ft m
Noncombustible unobstructed 130 12.1 12 3.7
Noncombustible obstructed 130 12.1 12 3.7
Combustible unobstructed 130 12.1 12 3.7
Combustible obstructed 100 9.3 10 3.0
Rack storage combustible obstructed 100 9.3 10 3.0
Rack storage unobstructed and noncombustible obstructed 100 9.3 12 3.7
In any case, the maximum area of coverage of any sprinkler shall not exceed 130 ft2 (12.1 m2).
The minimum allowable protection area of coverage for a sprinkler (As) shall be not less than 80 ft2 (7.4 m2).
Under unobstructed and obstructed noncombustible construction and unobstructed combustible construction, the distance between sprinklers shall be limited to not more than 12 ft (3.7 m) between sprinklers, as shown in Table 8.11.2.2.1.
Under obstructed combustible construction, the maximum distance shall be limited to 10 ft (3 m).
The distance from sprinklers to walls shall not exceed one-half of the allowable distance permitted between sprinklers as indicated in Table 8.11.2.2.1.
Sprinklers shall be located a minimum of 4 in. (100 mm) from a wall.
Sprinklers shall be spaced not less than 8 ft (2.4 m) on center.
Under unobstructed construction, the distance between the sprinkler deflector and the ceiling shall be a minimum of 6 in. (150 mm) and a maximum of 8 in. (200 mm).
Under obstructed construction, the sprinkler deflector shall be located in accordance with one of the following arrangements:
  1. Installed with the deflectors located a minimum of 6 in. (150 mm) and a maximum of 12 in. (300 mm) from the ceiling.
  2. Installed with the deflectors within the horizontal planes 1 in. to 6 in. (25 mm to 150 mm) below wood joist, composite wood joist, solid obstructed noncombustible, or solid obstructed limited combustible construction, to a maximum distance of 22 in. (550 mm) below the ceiling/roof or deck. Where CMSA sprinklers are installed under open wood joist construction, their minimum operating pressure shall be 50 psi (3.4 bar) for a K-11.2 (160) sprinkler or 22 psi (1.5 bar) for a K-16.8 (240) sprinkler in accordance with 16.2.2.4, 16.3.2.4, and 17.2.2.3.
  3. Installed with deflectors of sprinklers under concrete tee construction with stems spaced less than 7 ft 6 in. (2.3 m) but more than 3 ft (900 mm) on centers, regardless of the depth of the tee, located at or above a horizontal plane 1 in. (25 mm) below the bottom of the stems of the tees and in compliance with Table 8.11.5.1.2.
Deflectors of sprinklers shall be aligned parallel to ceilings or roofs.
Sprinklers shall be located so as to minimize obstructions to discharge as defined in 8.5.5.2 and 8.5.5.3, or additional sprinklers shall be provided to ensure adequate coverage of the hazard.
Sprinklers shall be arranged to comply with 8.5.5.2, Table 8.11.5.1.2, and Figure 8.11.5.1.2.
Table 8.11.5.1.2 Positioning of Sprinklers to Avoid Obstructions to Discharge (CMSA Sprinklers)
Distance from Sprinkler to Side of Obstruction (A) Maximum Allowable Distance of Deflector Above Bottom of Obstruction (B)
[in. (mm)]
Less than 1 ft (300 mm) 0 (0)
1 ft (300 mm) to less than 1 ft 6 in. (450 mm) 11/2 (35)
1 ft 6 in. (450 mm) to less than 2 ft (600 mm) 3 (75)
2 ft (600 mm) to less than 2 ft 6 in. (750 mm) 51/2 (140)
2 ft 6 in. (750 mm) to less than 3 ft (900 mm) 8 (200)
3 ft (900 mm) to less than 3 ft 6 in. (1.1 m) 10 (250)
3 ft 6 in. (1.1 m) to less than 4 ft (1.2 m) 12 (300)
4 ft (1.2 m) to less than 4 ft 6 in. (1.4 m) 15 (375)
4 ft 6 in. (1.4 m) to less than 5 ft (1.5 m) 18 (450)
5 ft (1.5 m) to less than 5 ft 6 in. (1.7 m) 22 (550)
5 ft 6 in. (1.7 m) to less than 6 ft (1.8 m) 26 (650)
6 ft (1.8 m) 31 (775)
Note: For A and B, refer to Figure 8.11.5.1.2.
FIGURE 8.11.5.1.2 Positioning of Sprinkler to Avoid Obstruction to Discharge (CMSA Sprinklers).
The requirements of 8.11.5.1.2 shall not apply where sprinklers are positioned on opposite sides of the obstruction.
Continuous or noncontinuous obstructions less than or equal to 36 in. (900 mm) below the sprinkler deflector that prevent the pattern from fully developing shall comply with 8.11.5.2.
Regardless of the rules of this section, solid continuous obstructions shall meet the requirements of 8.11.5.1.2 or 8.11.5.1.3.
Unless the requirements of 8.11.5.1.2 or 8.11.5.1.3 are met, for obstructions 8 in. (200 mm) or less in width, as shown in Figure 8.11.5.2.1.3, sprinklers shall be positioned such that they are located at least a distance three times greater than the maximum dimension of the obstruction from the sprinkler (e.g., webs and chord members, pipe, columns, and fixtures).
A ≥ 3C or 3D
(Use dimension C or D, whichever is greater)
FIGURE 8.11.5.2.1.3 Minimum Distance from Obstruction (CMSA Sprinklers).
Upright sprinklers shall be positioned with respect to branch lines in accordance with one of the following:
  1. Upright sprinklers shall be permitted to be attached directly to branch lines less than or equal to 4 in. (100 mm) nominal in diameter.
  2. Upright sprinklers shall be permitted to be offset horizontally a minimum of 12 in. (300 mm) from the pipe.
  3. Upright sprinklers shall be permitted to be supplied by a riser nipple (sprig) to elevate the sprinkler deflector a minimum of 12 in. (300 mm) from the centerline of any pipe over 4 in. (100 mm) nominal in diameter.
Continuous or noncontinuous obstructions that interrupt the water discharge in a horizontal plane below the sprinkler deflector in a manner to limit the distribution from reaching the protected hazard shall comply with 8.11.5.3.
Sprinklers shall be positioned with respect to fluorescent lighting fixtures, ducts, and obstructions more than 24 in. (600 mm) wide and located entirely below the sprinklers so that the minimum horizontal distance from the near side of the obstruction to the center of the sprinkler is not less than the value specified in Table 8.11.5.3.2 and Figure 8.11.5.3.2.
Table 8.11.5.3.2 Obstruction Entirely Below Sprinkler (CMSA Sprinklers)
Minimum Distance to Side of Obstruction (ft) (A) Distance of Deflector Above Bottom of Obstruction (B) [in. (mm)]
Less than 6 in. (150 mm) 11/2 (35)
6 in. (150 mm) to less than 12 in. (300 mm) 3 (75)
12 in. (300 mm) to less than 18 in. (450 mm) 4 (100)
18 in. (450 mm) to less than 24 in. (600 mm) 5 (125)
24 in. (600 mm) to less than 30 in. (750 mm) 51/2 (140)
30 in. (750 mm) to less than 36 in. (900 mm) 6 (150)
Note: For A and B, refer to Figure 8.11.5.3.2.
FIGURE 8.11.5.3.2 Obstruction Entirely Below Sprinkler (CMSA Sprinklers).
Sprinklers installed under open gratings shall be shielded from the discharge of overhead sprinklers.
Where the bottom of the obstruction is located 24 in. (600 mm) or more below the sprinkler deflectors, the following shall occur:
  1. Sprinklers shall be positioned so that the obstruction is centered between adjacent sprinklers in accordance with Figure 8.11.5.3.4.
  2. The obstruction width shall meet the following requirements:
    1. The obstruction shall be limited to a maximum width of 24 in. (600 mm) in accordance with Figure 8.11.5.3.4.
    2. Where the obstruction is greater than 24 in. (600 mm) wide, one or more lines of sprinklers shall be installed below the obstruction.
  3. The obstruction extension shall meet the following requirements:
    1. The obstruction shall not extend more than 12 in. (300 mm) to either side of the midpoint between sprinklers in accordance with Figure 8.11.5.3.4.
    2. Where the extensions of the obstruction exceed 12 in. (300 mm), one or more lines of sprinklers shall be installed below the obstruction.
  4. At least 18 in. (450 mm) clearance shall be maintained between the top of storage and the bottom of the obstruction in accordance with Figure 8.11.5.3.4.
FIGURE 8.11.5.3.4 Obstruction More Than 24 in. (600 mm) Below Sprinklers (CMSA Sprinklers).
In the special case of an obstruction running parallel to or directly below a branch line, the following shall occur:
  1. The sprinkler shall be located at least 36 in. (900 mm) above the top of the obstruction in accordance with Figure 8.11.5.3.5.
  2. The obstruction shall be limited to a maximum width of 12 in. (300 mm) in accordance with Figure 8.11.5.3.5.
  3. The obstruction shall be limited to a maximum extension of 6 in. (150 mm) to either side of the centerline of the branch line in accordance with Figure 8.11.5.3.5.
FIGURE 8.11.5.3.5 Obstruction More Than 36 in. (914 mm) Below Sprinklers (CMSA Sprinklers).
The clearance between the deflector and the top of storage shall be 36 in. (900 mm) or greater.
All requirements of Section 8.5 shall apply except as modified in Section 8.12.
The protection area of coverage per sprinkler (As) shall be determined in accordance with 8.5.2.1.
The maximum allowable protection area of coverage for a sprinkler (As) shall be in accordance with the value indicated in Table 8.12.2.2.1.
Table 8.12.2.2.1 Protection Areas and Maximum Spacing of ESFR Sprinklers
Construction Type Ceiling/Roof Heights Up to 30 ft (9.1 m)   Ceiling/Roof Heights Over 30 ft (9.1 m)
Protection Area   Spacing   Protection Area   Spacing
ft2 m2   ft m   ft2 m2   ft m
Noncombustible unobstructed 100 9.3   12 3.7   100 9.3   10 3.0
Noncombustible obstructed 100 9.3   12 3.7   100 9.3   10 3.0
Combustible unobstructed 100 9.3   12 3.7   100 9.3   10 3.0
Combustible obstructed N/A   N/A   N/A   N/A
Unless the requirements of 8.12.2.2.3 are met, the maximum area of coverage of any sprinkler shall not exceed 100 ft2 (9.3 m2).
Deviations from the maximum sprinkler spacing shall be permitted to eliminate obstructions created by structural elements (such as trusses, bar joists, and wind bracing) by moving a sprinkler along the branch line a maximum of 1 ft (300 mm) from its allowable spacing, provided coverage for that sprinkler does not exceed 110 ft2 (10.2 m2) per sprinkler where all of the following conditions are met:
  1. The average actual floor area protected by the moved sprinkler and the adjacent sprinklers shall not exceed 100 ft2 (9.3 m2).
  2. Adjacent branch lines shall maintain the same pattern.
  3. In no case shall the distance between sprinklers exceed 12 ft (3.7 m).
Deviations from the maximum sprinkler spacing shall be permitted to eliminate obstructions created by structural elements (such as trusses, bar joists, and wind bracing) by moving a single branch line a maximum of 1 ft (300 mm) from its allowable spacing, provided coverage for the sprinklers on that branch line and the sprinklers on the branch line it is moving away from does not exceed 110 ft2 (10.2 m2) per sprinkler where all of the following conditions are met:
  1. The average actual floor area protected by the sprinklers on the moved branch line and the sprinklers on the adjacent branch lines shall not exceed 100 ft2 (9.3 m2) per sprinkler.
  2. In no case shall the distance between sprinklers exceed 12 ft (3.7 m).
  3. It shall not be permitted to move a branch line where there are moved sprinklers on a branch line that exceed the maximum sprinkler spacing.
The minimum allowable protection area of coverage for a sprinkler (As) shall not be less than 64 ft2 (5.92).
The maximum distance between sprinklers shall be in accordance with the following:
  1. Where the storage height is less than or equal to 25 ft (7.6 m) and the ceiling height is less than or equal to 30 ft (9.1 m), the distance between sprinklers shall be limited to not more than 12 ft (3.7 m) between sprinklers as shown in Table 8.12.2.2.1.
  2. Unless the requirements of 8.12.3.1(3) or 8.12.3.1(4) are met, where the storage height exceeds 25 ft (7.6 m) and ceiling height exceeds 30 ft (9.1 m), the distance between sprinklers shall be limited to not more than 10 ft (3.0 m) between sprinklers.
  3. *Regardless of the storage or ceiling height arrangement, deviations from the maximum sprinkler spacing shall be permitted to eliminate obstructions created by structural elements (such as trusses, bar joists, and wind bracing) by moving a sprinkler along the branch line a maximum of 1 ft (300 mm) from its allowable spacing, provided coverage for that sprinkler does not exceed 110 ft2 (10.2 m2) where all of the following conditions are met:
    1. The average actual floor area protected by the moved sprinkler and the adjacent sprinklers shall not exceed 100 ft2 (9.3 m2).
    2. Adjacent branch lines shall maintain the same pattern.
    3. In no case shall the distance between sprinklers exceed 12 ft (3.7 m).
  4. Where branch lines are parallel to trusses and bar joists, deviations from the maximum sprinkler spacing shall be permitted to eliminate obstructions created by structural elements (such as trusses, bar joists, and wind bracing) by moving a single branch line a maximum of 1 ft (300 mm) from its allowable spacing, provided coverage for the sprinklers on that branch line and the sprinklers on the branch line it is moving away from does not exceed 110 ft2 (10.2 m2) per sprinkler where all of the following conditions are met:
    1. The average actual floor area protected by the sprinklers on the moved branch line and the sprinklers on the adjacent branch lines shall not exceed 100 ft2 (9.3 m2) per sprinkler.
    2. In no case shall the distance between sprinklers exceed 12 ft (3.7 m).
    3. It shall not be permitted to move a branch line where there are moved sprinklers on a branch line that exceed the maximum sprinkler spacing.
The distance from sprinklers to walls shall not exceed one-half of the allowable distance permitted between sprinklers as indicated in Table 8.12.2.2.1.
Sprinklers shall be located a minimum of 4 in. (100 mm) from a wall.
Sprinklers shall be spaced not less than 8 ft (2.4 m) on center.
Pendent sprinklers with a nominal K-factor of K-14 (200) shall be positioned so that deflectors are a maximum 14 in. (350 mm) and a minimum 6 in. (150 mm) below the ceiling.
Pendent sprinklers with a nominal K-factor of K-16.8 (240) shall be positioned so that deflectors are a maximum 14 in. (350 mm) and a minimum 6 in. (150 mm) below the ceiling.
Pendent sprinklers with a nominal K-factor of K-22.4 (320) and K-25.2 (360) shall be positioned so that deflectors are a maximum 18 in. (450 mm) and a minimum 6 in. (150 mm) below the ceiling.
Upright sprinklers with a nominal K-factor of K-14 (200) shall be positioned so that the deflector is 3 in. to 12 in. (75 mm to 300 mm) below the ceiling.
Upright sprinklers with a nominal K-factor of K-16.8 (240) shall be positioned so that the deflector is 3 in. to 12 in. (75 mm to 300 mm) below the ceiling.
With obstructed construction, the branch lines shall be permitted to be installed across the beams, but sprinklers shall be located in the bays and not under the beams.
Deflectors of sprinklers shall be aligned parallel to ceilings or roofs.
Sprinklers shall be arranged to comply with Table 8.12.5.1.1 and Figure 8.12.5.1.1 for obstructions at the ceiling, such as beams, ducts, lights, and top chords of trusses and bar joists.
Table 8.12.5.1.1 Positioning of Sprinklers to Avoid Obstructions to Discharge (ESFR Sprinklers)
Distance from Sprinkler to Side of Obstruction (A) Maximum Allowable Distance of Deflector Above Bottom of Obstruction (B)
[in. (mm)]
Less than 1 ft (300 mm) 0 (0)
1 ft (300 mm) to less than 1 ft 6 in. (450 mm) 11/2 (35)
1 ft 6 in. (450 mm) to less than 2 ft (600 mm) 3 (75)
2 ft (600 mm) to less than 2 ft 6 in. (750 mm) 51/2 (140)
2 ft 6 in. (750 mm) to less than 3 ft (900 mm) 8 (200)
3 ft (900 mm) to less than 3 ft 6 in. (1.1 m) 10 (250)
3 ft 6 in. (1.1 m) to less than 4 ft (1.2 m) 12 (300)
4 ft (1.2 m) to less than 4 ft 6 in. (1.4 m) 15 (375)
4 ft 6 in. (1.4 m) to less than 5 ft (1.5 m) 18 (450)
5 ft (1.5 m) to less than 5 ft 6 in. (1.7 m) 22 (550)
5 ft 6 in. (1.7 m) to less than 6 ft (1.8 m) 26 (650)
6 ft (1.8 m) 31 (775)
Note: For A and B, refer to Figure 8.12.5.1.1.
FIGURE 8.12.5.1.1 Positioning of Sprinkler to Avoid Obstruction to Discharge (ESFR Sprinklers).
The requirements of 8.12.5.1.1 shall not apply where sprinklers are spaced on opposite sides of obstructions less than 24 in. (600 mm) wide, provided the distance from the centerline on the obstructions to the sprinklers does not exceed one-half the allowable distance between sprinklers.
Sprinklers with a special obstruction allowance shall be installed according to their listing.
Sprinklers shall be arranged with respect to obstructions in accordance with one of the following:
  1. Sprinklers shall be installed below isolated noncontinuous obstructions that restrict only one sprinkler and are located below the elevation of sprinklers such as light fixtures and unit heaters.
  2. Additional sprinklers shall not be required where the obstruction is 2 ft (600 mm) or less in width and the sprinkler is located horizontally 1 ft (300 mm) or greater from the nearest edge of the obstruction.
  3. Additional sprinklers shall not be required where sprinklers are positioned with respect to the bottom of obstructions in accordance with 8.12.5.1.
  4. Additional sprinklers shall not be required where the obstruction is 2 in. (50 mm) or less in width and is located a minimum of 2 ft (600 mm) below the elevation of the sprinkler deflector or is positioned a minimum of 1 ft (300 mm) horizontally from the sprinkler.
  5. Sprinklers with a special obstruction allowance shall be installed according to their listing.
Sprinklers shall be arranged with respect to obstructions in accordance with one of the following:
  1. Sprinklers shall be installed below continuous obstructions, or they shall be arranged to comply with Table 8.12.5.1.1 for horizontal obstructions entirely below the elevation of sprinklers that restrict sprinkler discharge pattern for two or more adjacent sprinklers such as ducts, lights, pipes, and conveyors.
  2. Additional sprinklers shall not be required where the obstruction is 2 in. (50 mm) or less in width and is located a minimum of 2 ft (600 mm) below the elevation of the sprinkler deflector or is positioned a minimum of 1 ft (300 mm) horizontally from the sprinkler.
  3. Additional sprinklers shall not be required where the obstruction is 1 ft (300 mm) or less in width and located a minimum of 1 ft (300 mm) horizontally from the sprinkler.
  4. Additional sprinklers shall not be required where the obstruction is 2 ft (600 mm) or less in width and located a minimum of 2 ft (600 mm) horizontally from the sprinkler.
  5. Ceiling sprinklers shall not be required to comply with Table 8.12.5.1.1 where a row of sprinklers is installed under the obstruction.
ESFR sprinklers shall be positioned a minimum of 1 ft (300 mm) horizontally from the nearest edge to any bottom chord of a bar joist or open truss.
The requirements of 8.12.5.3.2 shall not apply where upright sprinklers are located over the bottom chords of bar joists or open trusses that are 4 in. (100 mm) maximum in width.
For pipes, conduits, or groups of pipes and conduit to be considered individual, they must be separated from the closest adjacent pipe, conduit, cable tray, or similar obstructions by a minimum of three times the width of the adjacent pipe, conduit, cable tray, or similar obstruction.
Sprinklers installed under open gratings shall be of the intermediate level/rack storage type or otherwise shielded from the discharge of overhead sprinklers.
Quick-response spray sprinklers shall be permitted to be utilized under overhead doors.
Sprinklers with a special obstruction allowance shall be installed according to their listing.
The clearance between the deflector and the top of storage shall be 36 in. (900 mm) or greater.
The area protected by a single system of sprinklers in racks shall not exceed 40,000 ft2 (3720 m2) of floor area occupied by the racks, including aisles, regardless of the number of levels of in-rack sprinklers.
Sprinklers in racks shall be ordinary-temperature standard-response or quick-response classification with a nominal K-factor of K-5.6 (80), K-8.0 (115), or K-11.2 (160), pendent or upright.
Sprinklers with intermediate- and high-temperature ratings shall be used near heat sources as required by 8.3.2.
Water shields shall be provided directly above in-rack sprinklers, or listed intermediate level/rack storage sprinklers shall be used where there is more than one level, if not shielded by horizontal barriers. (See Section C.3.)
Where in-rack sprinklers are not shielded by horizontal barriers, water shields shall be provided above the sprinklers, or listed intermediate level/rack storage sprinklers shall be used.
The location, position, and spacing of in-rack sprinklers shall comply with the requirements in Chapters 12 through 20 as applicable.
In-rack sprinklers shall be permitted to be placed less than 6 ft (1.8 m) on center.
In-rack sprinklers shall not be required to meet the obstruction criteria and clearance from storage requirements of Section 8.5.
Pilot line detectors and related components including pipe and fittings shall be corrosion resistant when installed in areas exposed to weather or corrosive conditions.
Where subject to mechanical or physical damage, pilot line detectors and related detection system components shall be protected.
Where spray sprinklers are used as pilot line detectors, they shall be installed in accordance with Section 8.14 and the spacing and location rules of Section 8.6, except that the obstruction to water distribution rules for automatic sprinklers shall not be required to be followed.
Where located under a ceiling, pilot sprinklers shall be positioned in accordance with the requirements of Section 8.6.
The temperature rating of spray sprinklers utilized as pilot line detectors shall be selected in accordance with 8.3.2.
Maximum horizontal spacing for indoor locations shall not exceed 12 ft (3.7 m).
Pilot line detectors shall be permitted to be spaced more than 22 in. (550 mm) below a ceiling or deck where the maximum spacing between pilot line detectors is 10 ft (3.0 m) or less.
Other maximum horizontal spacing differing from those required in 8.14.5 shall be permitted where installed in accordance with their listing.
Pilot line detectors located outdoors, such as in open process structures, shall be spaced such that the elevation of a single level of pilot line detectors and between additional levels of pilot line detectors shall not exceed 17 ft (5.2 m).
The maximum distance between pilot line detectors installed outdoors shall not exceed 8 ft (2.4 m).
The horizontal distance between pilot line detectors installed outdoors on a given level shall be permitted to be increased to 10 ft (3.0 m) when all of the following conditions are met:
  1. The elevation of the first level does not exceed 15 ft (4.6 m).
  2. The distance between additional levels does not exceed 12 ft (3.7 m).
  3. The pilot line actuators are staggered vertically.
Alternate vertical spacing of pilot line detectors differing from those required in 8.14.8.1 shall be permitted where installed in accordance with their listing.
Pilot line detectors located in open-sided buildings shall follow the indoor spacing rules.
A row of pilot line detectors spaced in accordance with the outdoor pilot line detector spacing rules shall be located along the open sides of open-sided buildings.
Pilot line detectors located under open gratings shall be spaced in accordance with the outdoor rules.
Where two or more adjacent water spray systems in one fire area are controlled by separate pilot line detector systems, the detectors on each system shall be spaced independently as if the dividing line between the systems were a wall or draft curtain.
Where pilot line detectors are installed in water cooling tower applications, they shall be in accordance with Section 22.21.
Pipe supplying pilot line detectors shall be permitted to be supported from the same points of hanger attachment as the piping system it serves.
Pipe supplying pilot line detectors shall not be required to meet the requirements of 9.3.5.
Concealed spaces of exposed combustible construction shall be protected by sprinklers except in concealed spaces where sprinklers are not required to be installed by 8.15.1.2.1 through 8.15.1.2.18 and 8.15.6.
Concealed spaces of noncombustible and limited-combustible construction with minimal combustible loading having no access shall not require sprinkler protection.
Upcodes Diagrams
The space shall be considered a concealed space even with small openings such as those used as return air for a plenum.
Small openings with a combined total area of not more than 20 percent of the ceiling, construction feature, or plane used to determine the boundaries of the concealed space shall be permitted where length greater than 4 ft (1.2 m) shall not have a width greater than 8 in. (200 mm).
The space above cloud ceilings meeting the requirements in 8.15.24.1 and having openings with a combined total area of not more than 20 percent of the ceiling, construction feature, or plane used to determine the boundaries of the concealed space shall be permitted.
Concealed spaces of noncombustible and limited- combustible construction with limited access and not permitting occupancy or storage of combustibles shall not require sprinkler protection.
Upcodes Diagrams
The space shall be considered a concealed space even with small openings such as those used as return air for a plenum.
Concealed spaces formed by studs or joists with less than 6 in. (150 mm) between the inside or near edges of the studs or joists shall not require sprinkler protection. (See Figure 8.6.4.1.5.1.)
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Concealed spaces formed by bar joists with less than 6 in. (150 mm) between the roof or floor deck and ceiling shall not require sprinkler protection.
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Concealed spaces formed by ceilings attached directly to or within 6 in. (150 mm) of wood joist or similar solid member construction shall not require sprinkler protection.
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Concealed spaces formed by ceilings attached to composite wood joist construction either directly or onto metal channels not exceeding 1 in. (25 mm) in depth, provided the joist channels are firestopped into volumes each not exceeding 160 ft3 (4.5 m3) using materials equivalent to the web construction and at least 31/2 in. (90 mm) of batt insulation is installed at the bottom of the joist channels when the ceiling is attached utilizing metal channels, shall not require sprinkler protection.
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Concealed spaces filled with noncombustible insulation shall not require sprinkler protection.
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A maximum 2 in. (50 mm) air gap at the top of the space shall be permitted.
Concealed spaces within wood joist construction and composite wood joist construction having noncombustible insulation filling the space from the ceiling up to the bottom edge of the joist of the roof or floor deck, provided that in composite wood joist construction the joist channels separated into volumes each not exceeding 160 ft3 (4.5 m3) to the full depth of the composite wood joist with material equivalent to the web construction, shall not require sprinkler protection.
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Concealed spaces over isolated small compartments not exceeding 55 ft2 (5.1 m2) in area shall not require sprinkler protection.
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Concealed spaces where rigid materials are used and the exposed surfaces have a flame spread index of 25 or less, and the materials have been demonstrated not to propagate fire more than 10.5 ft (3.2 m) when tested in accordance with ASTM E84, Standard Test Method of Surface Burning Characteristics of Building Materials, or ANSI/UL 723, Standard for Test for Surface Burning Characteristics of Building Materials, extended for an additional 20 minutes in the form in which they are installed, shall not require sprinkler protection.
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Concealed spaces in which the exposed materials are constructed entirely of fire retardant-treated wood as defined by NFPA 703 shall not require sprinkler protection.
Upcodes Diagrams
Noncombustible concealed spaces having exposed combustible insulation where the heat content of the facing and substrate of the insulation material does not exceed 1000 Btu/ft2 (11,400 kJ/m2) shall not require sprinkler protection.
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Concealed spaces below insulation that is laid directly on top of or within wood joists or composite wood joists used as ceiling joists in an otherwise sprinklered concealed space, with the ceiling attached directly to the bottom of the joists, shall not require sprinkler protection.
Upcodes Diagrams
Vertical pipe chases under 10 ft2 (0.9 m2), where provided in multifloor buildings where the chases are firestopped at each floor using materials equivalent to the floor construction, and where such pipe chases shall contain no sources of ignition, piping shall be water-filled or noncombustible and pipe penetrations at each floor shall be properly sealed and shall not require sprinkler protection.
Exterior columns under 10 ft2 (0.9 m2) in area, formed by studs or wood joist supporting exterior canopies that are fully protected with a sprinkler system, shall not require sprinkler protection.
Concealed spaces formed by noncombustible or limited-combustible ceilings suspended from the bottom of wood joists, composite wood joists, wood bar joists, or wood trusses that have insulation filling all of the gaps between the bottom of the trusses or joists, and where sprinklers are present in the space above the insulation within the trusses or joists, shall not require sprinkler protection.
The heat content of the facing, substrate, and support of the insulation material shall not exceed 1000 Btu/ft2 (11,400 kJ/m2).
Concealed spaces formed by noncombustible or limited-combustible ceilings suspended from the bottom of wood joists and composite wood joists with a maximum nominal chord width of 2 in. (50 mm), where joist spaces are full of noncombustible batt insulation with a maximum 2 in. (50 mm) air space between the decking material and the top of the batt insulation shall not require sprinklers.
Facing that meets the requirements for noncombustible or limited-combustible material covering the surface of the bottom chord of each joist and secured in place per the manufacturer's recommendations shall not require sprinklers.
Sprinklers shall be permitted to be omitted from within combustible soffits, eaves, overhangs, and decorative frame elements that are constructed in accordance with 8.15.1.2.18.2 through 8.15.1.2.18.5.
Combustible soffits, eaves, overhangs, and decorative frame elements shall not exceed 4 ft 0 in. (1.2 m) in width.
Combustible soffits, eaves, overhangs, and decorative frame elements shall be draftstopped, with a material equivalent to that of the soffit, into volumes not exceeding 160 ft3 (4.5 m3).
Combustible soffits, eaves, overhangs, and decorative frame elements shall be separated from the interior of the building by walls or roofs of noncombustible or limited-combustible construction.
Combustible soffits, eaves, overhangs, and decorative frame elements shall have no openings or unprotected penetrations directly into the building.
Sprinklers in concealed spaces having no access for storage or other use shall be installed in accordance with the requirements for light hazard occupancy.
Heat-Producing Devices with Composite Wood Joist Construction. Where heat-producing devices such as furnaces or process equipment are located in the joist channels above a ceiling attached directly to the underside of composite wood joist construction that would not otherwise require sprinkler protection of the spaces, the joist channel containing the heat-producing devices shall be sprinklered by installing sprinklers in each joist channel, on each side, adjacent to the heat-producing device.
When otherwise noncombustible or limited-combustible concealed spaces that would not require sprinkler protection have localized exposed combustible construction, or contain localized areas of exposed combustibles, the combustibles shall be permitted to be protected as follows:
  1. If the exposed combustibles are in the vertical partitions or walls around all or a portion of the enclosure, a single row of sprinklers spaced not over 12 ft (3.7 m) apart nor more than 6 ft (1.8 m) from the inside of the partition shall be permitted to protect the surface. The first and last sprinklers in such a row shall not be over 5 ft (1.5 m) from the ends of the partitions.
  2. If the exposed combustibles are in the horizontal plane, the area of the combustibles shall be permitted to be protected with sprinklers on a light hazard spacing. Additional sprinklers shall be installed no more than 6 ft (1.8 m) outside the outline of the area and not more than 12 ft (3.7 m) on center along the outline. When the outline returns to a wall or other obstruction, the last sprinkler shall not be more than 6 ft (1.8 m) from the wall or obstruction.
Sprinklers used in horizontal combustible concealed spaces (with a slope not exceeding 2 in 12) with combustible wood truss, wood joist construction, or bar joist construction having a combustible upper surface and where the depth of the space is less than 36 in. (900 mm) from deck to deck, from deck to ceiling, or with double wood joist construction with a maximum of 36 in. (900 mm) between the top of the bottom joist and the bottom of the upper joist shall be listed for such use.
Sprinklers specifically listed to provide protection of combustible concealed spaces described in 8.15.1.6 shall be permitted to be used in accordance with 8.3.1.2 where the space is less than 12 in. (300 mm) from deck to deck or deck to ceiling.
Sprinklers specifically listed to provide protection of combustible concealed spaces described in 8.15.1.6 shall be permitted to be used in accordance with 8.3.1.2 throughout the area when a portion of the area exceeds a depth of 36 in. (900 mm).
Sprinklers specifically listed to provide protection of combustible concealed spaces described in 8.15.1.6 shall be permitted to be used in accordance with 8.3.1.2 to protect composite wood joist construction with a maximum of 36 in. (900 mm) from deck to deck, from deck to ceiling, or with double composite wood joist construction with a maximum of 36 in. (900 mm) between the top of the bottom joist and the bottom of the upper joist.
Unless the requirements of 8.15.2.1.1 or 8.15.2.1.2 are met, one sprinkler shall be installed at the top of shafts.
Noncombustible or limited-combustible, nonaccessible vertical duct shafts shall not require sprinkler protection.
Noncombustible or limited-combustible, nonaccessible vertical electrical or mechanical shafts shall not require sprinkler protection.
Where vertical shafts have combustible surfaces, one sprinkler shall be installed at each alternate floor level.
Where a shaft having combustible surfaces is trapped, an additional sprinkler shall be installed at the top of each trapped section.
Where accessible vertical shafts have noncombustible surfaces, one sprinkler shall be installed near the bottom.
Sprinklers shall be installed beneath all stairways of combustible construction.
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Sprinklers shall be installed at the top of combustible stair shafts.
Sprinklers shall be installed under the landings at each floor level.
Sprinklers shall be installed beneath the lowest intermediate landing.
In noncombustible stair shafts having noncombustible stairs with noncombustible or limited-combustible finishes, sprinklers shall be installed at the top of the shaft and under the first accessible landing above the bottom of the shaft.
Where noncombustible stair shafts are divided by walls or doors, sprinklers shall be provided on each side of the separation.
Sprinklers shall be installed beneath landings or stairways where the area beneath is used for storage.
Sprinklers shall be permitted to be omitted from the bottom of the stairwell when the space under the stairs at the bottom is blocked off so that storage cannot occur.
Sprinklers shall be permitted to be omitted from exterior stair towers when the exterior walls of the stair tower are at least 50 percent open and when the stair tower is entirely of noncombustible construction.
When stairs have openings to each side of a fire wall(s), sprinklers shall be installed in the stair shaft at each floor landing with multiple openings.
Upcodes Diagrams
Unless the requirements of 8.15.4.4 are met, where moving stairways, staircases, or similar floor openings are unenclosed and where sprinkler protection is serving as the alternative to enclosure of the vertical opening, the floor openings involved shall be protected by closely spaced sprinklers in combination with draft stops in accordance with 8.15.4.2 and 8.15.4.3.
Draft stops shall meet all of the following criteria:
  1. The draft stops shall be located immediately adjacent to the opening.
  2. The draft stops shall be at least 18 in. (450 mm) deep.
  3. The draft stops shall be of noncombustible or limited-combustible material that will stay in place before and during sprinkler operation.
Sprinklers shall be spaced not more than 6 ft (1.8 m) apart and placed 6 in. to 12 in. (150 mm to 300 mm) from the draft stop on the side away from the opening.
Where sprinklers are closer than 6 ft (1.8 m), cross baffles shall be provided in accordance with 8.6.3.4.2.
Closely spaced sprinklers and draft stops are not required around large openings such as those found in shopping malls, atrium buildings, and similar structures where all adjoining levels and spaces are protected by automatic sprinklers in accordance with this standard and where the openings have all horizontal dimensions between opposite edges of 20 ft (6.1 m) or greater and an area of 1000 ft2 (95 m2) or greater.
Sidewall spray sprinklers shall be installed at the bottom of each elevator hoistway not more than 2 ft (600 mm) above the floor of the pit.
The sprinkler required at the bottom of the elevator hoistway by 8.15.5.1 shall not be required for enclosed, noncombustible elevator shafts that do not contain combustible hydraulic fluids.
Automatic fire sprinklers shall not be required in elevator machine rooms, elevator machinery spaces, control spaces, or hoistways of traction elevators installed in accordance with the applicable provisions in NFPA 101, or the applicable building code, where all of the following conditions are met:
  1. The elevator machine room, machinery space, control room, control space, or hoistway of traction elevator is dedicated to elevator equipment only.
  2. The elevator machine room, machine room, machinery space, control room, control space, or hoistway of traction elevators are protected by smoke detectors, or other automatic fire detection, installed in accordance with NFPA 72.
  3. The elevator machinery space, control room, control space, or hoistway of traction elevators is separated from the remainder of the building by walls and floor/ceiling or roof/ceiling assemblies having a fire resistance rating of not less than that specified by the applicable building code.
  4. No materials unrelated to elevator equipment are permitted to be stored in elevator machine rooms, machinery spaces, control rooms, control spaces, or hoistways of traction elevators.
  5. The elevator machinery is not of the hydraulic type.
Automatic sprinklers in elevator machine rooms or at the tops of hoistways shall be of ordinary- or intermediate-temperature rating.
Upright, pendent, or sidewall spray sprinklers shall be installed at the top of elevator hoistways.
The sprinkler required at the top of the elevator hoistway by 8.15.5.5 shall not be required where the hoistway for passenger elevators is noncombustible or limited-combustible and the car enclosure materials meet the requirements of ASME A17.1, Safety Code for Elevators and Escalators.
Sprinklers shall be installed at the top and bottom of elevator hoistways where elevators utilize combustible suspension means such as noncircular elastomeric-coated or polyurethane-coated steel belts.
The sprinklers in the elevator hoistway shall not be required when the suspension means provide not less than an FT-1 rating when tested to the vertical burn test requirements of UL 62, Flexible Cords and Cables, and UL 1581, Reference Standard for Electrical Wires, Cables, and Flexible Cords.
Unless the requirements of 8.15.6.2 are met, sprinklers shall be installed in spaces under all combustible ground floors and combustible exterior docks and platforms.
Sprinklers shall be permitted to be omitted from spaces under ground floors, exterior docks, and platforms where all of the following conditions exist:
  1. The space is not accessible for storage purposes and is protected against accumulation of wind-borne debris.
  2. The space contains no equipment such as conveyors or fuel-fired heating units.
  3. The floor over the space is of tight construction.
  4. No combustible or flammable liquids or materials that under fire conditions would convert into combustible or flammable liquids are processed, handled, or stored on the floor above the space.
Unless the requirements of 8.15.7.2, 8.15.7.3, or 8.15.7.4 are met, sprinklers shall be installed under exterior projections exceeding 4 ft (1.2 m) in width.
Sprinklers shall be permitted to be omitted where the exterior canopies, roofs, porte-cocheres, balconies, decks, and similar projections are constructed with materials that are noncombustible, limited-combustible, or fire retardant-treated wood as defined in NFPA 703, or where the projections are constructed utilizing a noncombustible frame, limited-combustibles, or fire retardant-treated wood with an inherently flame-resistant fabric overlay as demonstrated by Test Method 2 in accordance with NFPA 701.
Sprinklers shall be permitted to be omitted from below the exterior projections of combustible construction, provided the exposed finish material on the exterior projections are noncombustible, limited-combustible, or fire retardant-treated wood as defined in NFPA 703, and the exterior projections contain only sprinklered concealed spaces or any of the following unsprinklered combustible concealed spaces:
  1. Combustible concealed spaces filled entirely with noncombustible insulation
  2. Light or ordinary hazard occupancies where noncombustible or limited-combustible ceilings are directly attached to the bottom of solid wood joists so as to create enclosed joist spaces 160 ft3 (4.5 m3) or less in volume, including space below insulation that is laid directly on top or within the ceiling joists in an otherwise sprinklered attic [see 11.2.3.1.4(4)(d)]
  3. Concealed spaces over isolated small exterior projections not exceeding 55 ft2 (5.1 m2) in area
Sprinklers shall be permitted to be omitted from exterior exit corridors when the exterior walls of the corridor are at least 50 percent open and when the corridor is entirely of noncombustible construction.
Sprinklers shall be installed under exterior projections greater than 2 ft (600 mm) wide over areas where combustibles are stored.
Unless sprinklers are required by 8.15.8.1.2 or 8.15.8.1.3, sprinklers shall not be required in bathrooms that are located within dwelling units, that do not exceed 55 ft2 (5.1 m2) in area, and that have walls and ceilings of noncombustible or limited-combustible materials with a 15-minute thermal barrier rating, including the walls and ceilings behind any shower enclosure or tub.
Sprinklers shall be required in bathrooms of limited care facilities and nursing homes, as defined in NFPA 101.
Sprinklers shall be required in bathrooms opening directly onto public corridors or exitways.
Sprinklers are not required in clothes closets, linen closets, and pantries within dwelling units in hotels and motels where the area of the space does not exceed 24 ft2 (2.2 m2) and the walls and ceilings are surfaced with noncombustible or limited-combustible materials.
Sprinklers shall not be required in clothes closets of patient sleeping rooms in hospitals where the area of the closet does not exceed 6 ft2 (0.5 m2), provided the distance from the sprinkler in the patient sleeping room to the back wall of the closet does not exceed the maximum distance permitted by 8.5.3.2.
Where books or records are stored in fixed open book shelves, sprinklers shall be installed in accordance with one of the following:
  1. Sprinklers shall be permitted to be installed without regard to aisles where clearance between sprinkler deflectors and tops of stacks is 18 in. (450 mm) or more.
  2. Where the 18 in. (450 mm) clearance between sprinkler deflectors and tops of stacks cannot be maintained, sprinklers shall be installed in every aisle and at every tier of stacks with distance between sprinklers along aisles not to exceed 12 ft (3.7 m) in accordance with Figure 8.15.10(a).
  3. Where the 18 in. (450 mm) clearance between sprinkler deflectors and tops of stacks cannot be maintained and where vertical shelf dividers are incomplete and allow water distribution to adjacent aisles, sprinklers shall be permitted to be omitted in alternate aisles on each tier, and where ventilation openings are also provided in tier floors, sprinklers shall be staggered vertically in accordance with Figure 8.15.10(b).
FIGURE 8.15.10(a) Sprinklers in Multitier Bookstacks with Complete Vertical Dividers.
FIGURE 8.15.10(b) Sprinklers in Multitier Bookstacks with Incomplete Vertical Dividers.
Unless the requirements of 8.15.11.2 are met, sprinkler protection shall be required in electrical equipment rooms.
Sprinklers shall not be required in electrical equipment rooms where all of the following conditions are met:
  1. The room is dedicated to electrical equipment only.
  2. Only dry-type electrical equipment is used.
  3. Equipment is installed in a 2-hour fire-rated enclosure including protection for penetrations.
  4. No combustible storage is permitted to be stored in the room.
Duct protection shall be required to meet the requirements of 8.15.12 where required by the authority having jurisdiction or the applicable referenced code or standard.
Unless the requirements of 8.15.13.1.2 or 8.15.13.1.3 are met, ducts shall have one sprinkler located at the top of each vertical riser and at the midpoint of each offset.
Sprinklers shall not be required in a vertical riser located outside of a building, provided the riser does not expose combustible material or provided the interior of the building and the horizontal distance between the hood outlet and the vertical riser is at least 25 ft (7.6 m).
Horizontal exhaust ducts shall have sprinklers located on 10 ft (3.0 m) centers beginning no more than 5 ft (1.5 m) from the duct entrance.
Sprinklers in exhaust ducts subject to freezing shall be properly protected against freezing. (See 8.16.4.1.)
Access shall be provided to all sprinklers for inspection, testing, and maintenance.
A listed line strainer shall be installed in the main water supply preceding sprinklers having nominal K-factors smaller than K-2.8 (40).
Open-grid ceilings shall only be installed beneath sprinklers where one of the following is met:
  1. Open-grid ceilings in which the openings are 1/4 in. (6 mm) or larger in the least dimension, where the thickness or depth of the material does not exceed the least dimension of the opening, and where such openings constitute 70 percent of the area of the ceiling material. The spacing of the sprinklers over the open-grid ceiling shall then comply with the following:
    1. In light hazard occupancies where sprinkler spacing (either spray or old-style sprinklers) is less than 10 ft × 10 ft (3 m × 3 m), a minimum clearance of at least 18 in. (450 mm) shall be provided between the sprinkler deflectors and the upper surface of the open-grid ceiling. Where spacing is greater than 10 ft × 10 ft (3 m × 3 m) but less than 10 ft × 12 ft (3 m × 3.7 m), a clearance of at least 24 in. (600 mm) shall be provided from spray sprinklers and at least 36 in. (900 mm) from old-style sprinklers. Where spacing is greater than 10 ft × 12 ft (3 m × 3.7 m), a clearance of at least 48 in. (1.2 m) shall be provided.
    2. In ordinary hazard occupancies, open-grid ceilings shall be permitted to be installed beneath spray sprinklers only. Where sprinkler spacing is less than 10 ft × 10 ft (3 m × 3 m), a minimum clearance of at least 24 in. (600 mm) shall be provided between the sprinkler deflectors and the upper surface of the open-grid ceiling. Where spacing is greater than 10 ft × 10 ft (3 m × 3 m), a clearance of at least 36 in. (900 mm) shall be provided.
  2. Other types of open-grid ceilings shall be permitted to be installed beneath sprinklers where they are listed for such service and are installed in accordance with instructions contained in each package of ceiling material.
Drop-out ceilings and ceiling materials shall be permitted to be installed beneath sprinklers where the ceiling panels or ceiling materials are listed for that service and are installed in accordance with their listings.
Drop-out ceilings and ceiling materials meeting the criteria in 8.15.15.1 shall not be installed below quick-response or extended coverage sprinklers unless specifically listed for that application.
Drop-out ceilings and ceiling materials meeting the criteria in 8.15.15.1 shall not be considered ceilings within the context of this standard.
Piping installed above drop-out ceilings and ceiling materials meeting the criteria in 8.15.15.1 shall not be considered concealed piping.
Sprinklers shall not be installed beneath drop-out ceilings or ceiling materials meeting the criteria in 8.15.15.1.
Unless required by 8.15.16.2 or 8.15.16.3, old-style sprinklers shall not be used in a new installation.
Old-style sprinklers shall be installed in fur storage vaults.
Use of old-style sprinklers shall be permitted where construction features or other special situations require unique water distribution.
Sprinklers shall be installed under the roof at the ceiling, in spaces under the stage either containing combustible materials or constructed of combustible materials, and in all adjacent spaces and dressing rooms, storerooms, and workshops.
Where proscenium opening protection is required, a deluge system shall be provided with open sprinklers located not more than 3 ft (900 mm) away from the stage side of the proscenium arch and spaced up to a maximum of 6 ft (1.8 m) on center. (See Chapter 11 for design criteria.)
Stair towers, or other construction with incomplete floors, if piped on independent risers, shall be treated as one area with reference to pipe sizes.
Unless the requirements of 8.15.19.3, 8.15.19.4, or 8.15.19.5 are met, return bends shall be used where pendent sprinklers are supplied from a raw water source, a mill pond, or open-top reservoirs.
Return bends shall be connected to the top of branch lines in order to avoid accumulation of sediment in the drop nipples in accordance with Figure 8.15.19.2.
FIGURE 8.15.19.2 Return Bend Arrangement.
Return bends shall not be required for deluge systems.
Return bends shall not be required where dry pendent sprinklers are used.
Return bends shall not be required for wet pipe systems where sprinklers with a nominal K-factor of K-11.2 (160) or larger are used.
In new installations expected to supply sprinklers below a ceiling, minimum 1 in. (25 mm) outlets shall be provided.
In new installations, it shall be permitted to provide minimum 1 in. (25 mm) outlets with hexagonal bushings to accommodate sprinklers attached directly to branch line fittings to allow for future system modifications.
When systems are revamped to accommodate added ceilings, sprinkler outlets utilized for new armover or drop nipples shall have hexagonal bushings removed.
When pipe schedule systems are revamped, a nipple not exceeding 4 in. (100 mm) in length shall be permitted to be installed in the branch line fitting.
All piping other than the nipple permitted in 8.15.20.4.1 and 8.15.20.4.3 shall be a minimum of 1 in. (25 mm) in diameter in accordance with Figure 8.15.20.4.2.
FIGURE 8.15.20.4.2 Nipple and Reducing Elbow Supplying Sprinkler Below Ceiling.
When it is necessary to pipe two new ceiling sprinklers from an existing outlet in an overhead system, the use of a nipple not exceeding 4 in. (100 mm) in length and of the same pipe thread size as the existing outlet shall be permitted, provided that a hydraulic calculation verifies that the design flow rate will be achieved in accordance with Figure 8.15.20.4.3.
FIGURE 8.15.20.4.3 Sprinklers in Concealed Space and Below Ceiling.
Where an armover is attached to connect to a sprinkler, the use of pipe nipples less than 1 in. (25 mm) in diameter shall not be permitted where seismic design is required on the system.
When hydraulically designed systems are revamped, any existing bushing shall be removed and a nipple not exceeding 4 in. (100 mm) in length shall be permitted to be installed in the branch line fitting.
Calculations shall be provided to verify that the system design flow rate will be achieved.
When it is necessary to pipe two new ceiling sprinklers from an existing outlet in an overhead system, any bushings shall be removed and the use of a nipple not exceeding 4 in. (100 mm) in length and of the same pipe thread size as the existing outlet shall be permitted, provided that a hydraulic calculation verifies that the design flow rate will be achieved.
Where an armover is attached to connect to a sprinkler, the use of pipe nipples less than 1 in. (25 mm) in diameter shall not be permitted where seismic design is required on the system.
Where necessary to place pipe that will be under air pressure underground, the pipe shall be protected against corrosion.
Unprotected cast-iron or ductile-iron pipe shall be permitted where joined with a gasketed joint listed for air service underground.
Where individual floor/zone control valves are not provided, a flanged joint or mechanical coupling shall be used at the riser at each floor for connections to piping serving floor areas in excess of 5000 ft2 (465 m2).
Where spaces have ceilings that are lower than the rest of the area, the space above this lower ceiling shall be sprinklered unless it complies with the rules of 8.15.1.2 for allowable unsprinklered concealed spaces.
Where the space above a drop ceiling is sprinklered, the sprinkler system shall conform to the rules of 11.1.2 and Section 12.3.
Where there is a noncombustible space above a noncombustible or limited-combustible drop ceiling that is sprinklered because it is open to an adjacent sprinklered space on only one side and where there is no possibility for storage above the drop ceiling, the sprinkler system shall be permitted to extend only as far into the space as 0.6 times the square root of the design area of the sprinkler system in the adjacent space.
The sprinkler system shall extend at least 24 ft (7.2 m) into the space above the ceiling.
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Sprinklers shall be permitted to be omitted above cloud ceilings where both of the following apply:
  1. *The openings around the cloud and the maximum sprinkler protection area meet the requirements of 8.15.1.2.1.2 and Table 8.15.24.1
  2. The requirements of 8.15.24.2 are met.
Table 8.15.24.1 Maximum Sprinkler Protection Area Based on Ceiling Cloud Width and Opening Width
Ceiling Cloud — Minimum Width Dimension
(ft)
Maximum Area (ft2) — Opening Width ≤0.5 in./ft of Ceiling Height Maximum Area (ft2) — Opening Width ≤0.75 in./ft of Ceiling Height Maximum Area (ft2) — Opening Width ≤1 in./ft of Ceiling Height
2—<2.5 175 70 NP
2.5—4 225 120 70
>4 225 150 150
When sprinklers are omitted from above a cloud ceiling in accordance with 8.15.24.1, the requirements of this section shall apply.
All sprinklers shall be quick response standard spray or extended coverage pendent or upright sprinklers.
Where extended coverage sprinklers are used, the maximum distance between sprinklers shall not exceed 16 ft (4.9 m).
Maximum cloud ceiling height shall not exceed 20 ft (6.1 m).
Maximum spacing shall not exceed the maximum requirements of Table 8.6.2.2.1(a) for light hazard and Table 8.6.2.2.1(b) for ordinary hazard.
Cloud ceilings shall be of smooth ceiling construction.
For irregular shaped ceiling clouds (not rectangular) the minimum width dimension shall be the smallest width dimension of the cloud and for the gap shall be the greatest dimension between clouds or adjacent walls as applicable.
Sprinkler protection shall not be required within revolving door enclosures.
Where sprinklers are used in combination with glazing as an alternative to a required fire-rated wall or window assembly, the sprinkler-protected assembly shall comply with the following:
  1. Sprinklers shall be listed as specific application window sprinklers unless the standard spray sprinklers are specifically permitted by the building code.
  2. Sprinklers shall be supplied by a wet-pipe system.
  3. Glazing shall be heat-strengthened, tempered, or glass ceramic and shall be fixed.
  4. Where the assembly is required to be protected from both sides, sprinklers shall be installed on both sides of the glazing.
  5. The use of sprinkler-protected glazing shall be limited to non-load-bearing walls.
  6. The glazed assembly shall not have any horizontal members that would interfere with uniform distribution of water over the surface of the glazing, and there shall be no obstructions between sprinklers and glazing that would obstruct water distribution.
  7. The water supply duration for the design area that includes the window sprinklers shall not be less than the required rating of the assembly
Each sprinkler system shall be provided with a listed indicating valve in an accessible location, so located as to control all automatic sources of water supply.
At least one listed indicating valve shall be installed in each source of water supply.
The requirements of 8.16.1.1.1.2 shall not apply to the fire department connection, and there shall be no shutoff valve in the fire department connection.
Valves on connections to water supplies, sectional control and isolation valves, and other valves in supply pipes to sprinklers and other fixed water-based fire suppression systems shall be supervised by one of the following methods:
  1. Central station, proprietary, or remote station signaling service
  2. Local signaling service that will cause the sounding of an audible signal at a constantly attended point
  3. Valves locked in the correct position
  4. Valves located within fenced enclosures under the control of the owner, sealed in the open position, and inspected weekly as part of an approved procedure
Floor control valves in high-rise buildings and valves controlling flow to sprinklers in circulating closed loop systems shall comply with 8.16.1.1.2.1(1) or 8.16.1.1.2.1(2).
The requirements of 8.16.1.1.2.1 shall not apply to underground gate valves with roadway boxes.
Where control valves are installed overhead, they shall be positioned so that the indicating feature is visible from the floor below.
A listed backflow prevention assembly shall be permitted to be considered a control valve, provided both control valves are listed for fire protection system use and an additional control valve shall not be required.
Where there is more than one source of water supply, a check valve shall be installed in each connection.
A listed backflow prevention device shall be considered a check valve, and an additional check valve shall not be required.
Where cushion tanks are used with automatic fire pumps, no check valve is required in the cushion tank connection.
Check valves shall be installed in a vertical (flow upwards) or horizontal position in accordance with their listing.
Where a single wet pipe sprinkler system is equipped with a fire department connection, the alarm valve is considered a check valve, and an additional check valve shall not be required.
In a connection serving as one source of supply, listed indicating valves or post-indicator valves shall be installed on both sides of all check valves required in 8.16.1.1.3.
The city services control valve (non-indicating control valve) shall be permitted to serve as the supply side control valve.
The requirements of 8.16.1.1.4.1 shall not apply to the check valve located in the fire department connection piping, and there shall be no control valves in the fire department connection piping.
The requirements of 8.16.1.1.4.1 shall not apply where the city connection serves as the only automatic source of supply to a wet pipe sprinkler system; a control valve is not required on the system side of the check valve or the alarm check valve.
Gravity tanks shall have listed indicating valves installed on both sides of the check valve.
When a pump is located in a combustible pump house or exposed to danger from fire or falling walls, or when a tank discharges into a private fire service main fed by another supply, either the check valve in the connection shall be located in a pit or the control valve shall be of the postindicator type located a safe distance outside buildings.
All control valves shall be located where accessible and free of obstructions.
Identification signs shall be provided at each valve to indicate its function and what it controls.
In portions of systems where all components are not listed for pressure greater than 175 psi (12 bar) and the potential exists for normal (nonfire condition) water pressure in excess of 175 psi (12 bar), a listed pressure-reducing valve shall be installed and set for an outlet pressure not exceeding 165 psi (11 bar) at the maximum inlet pressure.
Pressure gauges shall be installed on the inlet and outlet sides of each pressure-reducing valve.
A listed relief valve of not less than 1/2 in. (15 mm) in size shall be provided on the discharge side of the pressure-reducing valve set to operate at a pressure not exceeding the rated pressure of the components of the system.
A listed indicating valve shall be provided on the inlet side of each pressure-reducing valve, unless the pressure-reducing valve meets the listing requirements for use as an indicating valve.
Means shall be provided downstream of all pressure-reducing valves for flow tests at sprinkler system demand.
Where post-indicator valves are used, they shall be set so that the top of the post is 32 in. to 40 in. (800 mm to 1.0 m) above the final grade.
Post-indicator valves shall be properly protected against mechanical damage where needed.
The requirements of 8.16.1.3.1 shall not apply to wall post-indicator valves.
Where it is impractical to provide a postindicator valve, valves shall be permitted to be placed in pits with permission of the authority having jurisdiction.
When used, valve pits shall be of adequate size and accessible for inspection, operation, testing, maintenance, and removal of equipment contained therein.
Valve pits shall be constructed and arranged to properly protect the installed equipment from movement of earth, freezing, and accumulation of water.
Poured-in-place or precast concrete, with or without reinforcement, or brick (all depending upon soil conditions and size of pit) shall be appropriate materials for construction of valve pits.
Other approved materials shall be permitted to be used for valve pit construction.
Where the water table is low and the soil is porous, crushed stone or gravel shall be permitted to be used for the floor of the pit. [See Figure A.8.17.2(b) for a suggested arrangement.]
Valve pits located at or near the base of the riser of an elevated tank shall be designed in accordance with Chapter 9 of NFPA 22.
The location of the valve shall be clearly marked, and the cover of the pit shall be kept free of obstructions.
Unless the requirements of 8.16.1.5.2 or 8.16.1.5.3 are met, where sprinklers are installed in racks, separate indicating control valves and drains shall be provided and arranged so that ceiling and in-rack sprinklers can be controlled independently.
Installation of 20 or fewer in-rack sprinklers supplied by any one ceiling sprinkler system shall not require a separate indicating control valve.
The separate indicating valves shall be permitted to be arranged as sectional control valves supplied from the ceiling sprinkler system where in-rack sprinklers are required and the racks including the adjacent aisles occupy 8000 ft2 (740 m2) or less of the area protected by the ceiling sprinklers.
All sprinkler pipe and fittings shall be installed so that the system can be drained.
On wet pipe systems, sprinkler pipes shall be permitted to be installed level.
Trapped piping shall be drained in accordance with 8.16.2.5.
Piping shall be pitched to drain as stated in 8.16.2.3.1 through 8.16.2.3.3.
In dry pipe system, branch lines shall be pitched at least 1/2 in. per 10 ft (4 mm/m), and mains shall be pitched at least 1/4 in. per 10 ft (2 mm/m) in nonrefrigerated areas.
In preaction systems, branch lines shall be pitched at least 1/2 in. per 10 ft (4 mm/m), and mains shall be pitched at least 1/4 in. per 10 ft (2 mm/m).