Heads up: There are no amended sections in this chapter.
This chapter shall apply to storage of plastic and rubber commodities stored in racks. The requirements of Chapter 12 shall apply unless modified by this chapter. (See Section C.9.)
This chapter also shall be used to determine protection for commodities that are not entirely Group A plastics but contain such quantities and arrangements of Group A plastics that they are deemed more hazardous than Class IV commodities.
Plastic commodities shall be protected in accordance with Figure 17.1.2.1. (See Section C.21.)

FIGURE 17.1.2.1 Decision Tree.

The design criteria of Chapter 17 for single- and double-row rack storage of Group A plastic commodities shall be applicable where aisles are 3.5 ft (1.1 m) or greater in width.
Storage with aisles less than 3.5 ft (1.1 m) shall be protected as multiple-row rack storage.
Group B plastics and free-flowing Group A plastics shall be protected the same as Class IV commodities.
Group C plastics shall be protected the same as Class III commodities.
Sprinkler protection criteria for the storage of Group A plastic commodities on racks shall be in accordance with Section 17.2 for storage up to 25 ft (7.6 m) and Section 17.3 for storage over 25 ft (7.6 m).
Protection criteria for Group A plastics shall be permitted for the protection of the same storage height and configuration of Class I, II, III, and IV commodities.
The ceiling design criteria for single-, double-, and multiple-row racks in Chapter 17 shall be based on open rack configurations as defined in 3.9.3.7.4.
The protection of Group A plastic commodities requiring a greater level of protection than is available from the overhead sprinkler system shall be permitted to be protected in accordance with 17.1.2.9.1 through 17.1.2.9.7.
Where the storage rack will not be solely dedicated to the storage of commodities requiring a greater level of protection than is available from the overhead sprinkler system, either of the following shall apply:
  1. Extend the protection prescribed by 17.1.2.9 horizontally one pallet load in all directions beyond the commodity storage area requiring the higher level of protection.
  2. Install a vertical barrier to segregate the commodities requiring the higher level of protection from any adjacent commodities.
Commodities that can be protected by the ceiling- level sprinkler system shall be permitted to be stored vertically above and horizontally adjacent to the portions of the storage rack equipped as prescribed by 17.1.2.9.
Horizontal barriers shall be installed at every tier level of the dedicated storage rack where the rack is equipped with solid shelves.
Where the dedicated storage rack is open-frame, horizontal barriers shall be installed at vertical increments not exceeding 12 ft (3.6 m).
The barriers shall span horizontally so that all flue spaces within the rack bay are covered.
A maximum 3 in. (75 mm) wide gap shall be permitted at rack uprights.
The solid barrier shall be installed on a horizontal plane within a rack, beneath which in-rack sprinklers shall be installed, as follows:

(A) The barrier shall be constructed of minimum 22 gauge (0.7 mm) sheet metal or of minimum 3/8 in. (10 mm) plywood.

(B) The barrier shall extend to both ends and both aisle faces of the racks covering up both the longitudinal and transverse flue spaces of the rack bays in which they are installed.

(C) The barrier shall be fitted to within 3 in. (75 mm) of any vertical rack member or other equipment that would create an opening, such as vertical in-rack sprinkler pipe drops.

Minimum K-8.0 (K-115) quick-response sprinklers (ceiling-level or in-rack) shall be installed beneath each horizontal barrier. The deflector of the sprinkler shall be located as close to the underside of the horizontal barrier as possible.

(A) For single-row racks, sprinklers shall be installed at each rack upright and at each rack mid-bay as shown in Figure 17.1.2.9.4.1(A).

FIGURE 17.1.2.9.4.1(A) Alternative Protection Single-Row Racks.

(B) The maximum linear spacing between sprinklers shall not exceed 5 ft (1.5 m).

(A) For double-row racks, sprinklers shall be installed at each rack upright within the longitudinal flue space and at the face of the rack and at the mid-bay face of each rack bay as shown in Figure 17.1.2.9.4.2(A).

FIGURE 17.1.2.9.4.2(A) Alternative Protection Double-Row Racks.

(B) The maximum linear spacing between sprinklers shall not exceed 5 ft (1.5 m) at the rack face and 10 ft (3.0 m) within the longitudinal flue space.

(A) For multiple-row racks, an alternating sprinkler arrangement shall be installed within adjacent transverse flue spaces, as shown in Figure 17.1.2.9.4.3(A), with sprinklers at the face of each flue space.

FIGURE 17.1.2.9.4.3(A) Alternative Protection Multiple-Row Racks.

(B) The maximum linear spacing between sprinklers at the face and each alternating bay shall not exceed 5 ft (1.5 m) and shall not exceed 10 ft (3.0 m) between sprinklers at every other bay.

The design of an in-rack sprinkler system shall be based on a minimum flow of 60 gpm (230 L/min) from the most remote six sprinklers for single-row racks or the most remote eight sprinklers for both double-row and multiple-row racks.
The in-rack sprinkler demand shall not be required to be hydraulically balanced with the ceiling-level sprinkler system.
The ceiling-level sprinkler system shall be designed based on the highest commodity hazard not protected by the criteria prescribed by 17.1.2.9.
Rack storage in movable racks shall be protected in the same manner as multiple-row racks.
Where fireproofing of building columns is not provided and storage heights are in excess of 15 ft (4.6 m), protection of building columns located wholly or partially within the rack footprint inclusive of flue space or within 12 in. (305 mm) of the footprint shall be protected in accordance with one of the following:
  1. In-rack sprinklers
  2. Sidewall sprinklers at the 15 ft (4.6 m) elevation, pointed toward one side of the steel column
  3. Provision of ceiling sprinkler density for a minimum of 2000 ft2 (186 m2) with ordinary temperature- or high temperature-rated sprinklers as shown in Table 17.1.4.1 for storage heights above 15 ft (4.6 m) up to and including 20 ft (6.1 m)
  4. Provision of CMSA or ESFR ceiling sprinkler protection

Table 17.1.4.1 Ceiling Sprinkler Densities for Protection of Steel Building Columns

Commodity
Classification
Aisle Width
4 ft (1.2 m) 8 ft (2.4 m)
gpm/ft2 (L/min)/m2 gpm/ft2 (L/min)/m2
Group A plastics 0.68 27.7 0.57 23.2
Where storage heights are in excess of 15 ft (4.6 m) and vertical rack members support the building structure, the vertical rack members shall be protected in accordance with one of the options in 17.1.4.1.
The flow from a column sprinkler(s) shall be permitted to be omitted from the sprinkler system hydraulic calculations.
Where solid shelving in single-, double-, and multiple-row racks exceeds 20 ft2 (1.9 m2) but does not exceed 64 ft2 (5.9 m2) in area, sprinklers shall not be required below every shelf, but shall be installed at the ceiling and below shelves at intermediate levels not more than 6 ft (1.8m) apart vertically. (See Section C.11.)
Where solid shelving in single-, double-, and multiple-row racks exceeds 64 ft2 (5.9 m2) in area or where the levels of storage exceed 6 ft (1.8 m), sprinklers shall be installed at the ceiling and below each level of shelving.
Where multiple-row racks of any height have no longitudinal flue or where double-row racks with storage up 25 ft (7.6 m) in height have no longitudinal flue, the situation shall not be considered solid shelves where transverse flues exist at maximum 5 ft (1.5 m) intervals and additional in-rack sprinklers shall not be required in accordance with 17.1.5.1 and 17.1.5.2.
The maximum horizontal spacing between in-rack sprinklers shall be 5 ft (1.5 m).
Ceiling design criteria for CMDA, CMSA, and ESFR sprinklers shall be an applicable option for open racks combined with in-rack sprinklers installed in accordance with the criteria for solid shelving.
Where the criteria in 17.1.5.7 are not met, the water demand for the in-rack sprinklers shall be based on a minimum flow of 30 gpm (115 L/min) discharging from the following number of sprinklers balanced to the ceiling sprinkler demand in accordance with Section 23.8:
  1. Eight sprinklers where only one level of in-rack sprinklers is installed
  2. Fourteen sprinklers (seven on each of the top two levels) when more than one level of in-rack sprinklers is installed
The water demand for in-rack sprinklers shall not be required to be balanced to the ceiling sprinkler demand where additional face sprinklers are installed under each solid shelf at rack uprights and the in-rack sprinklers are calculated to discharge at least 60 gpm (230 L/min) from eight sprinklers.
Where solid shelves obstruct only a portion of the rack, in-rack sprinklers shall be installed horizontally, within the flue a minimum of 4 ft (1.2 m) beyond the end of the solid shelf, and vertically as follows:
  1. In accordance with 17.1.5.1 and 17.1.5.2 for CMDA sprinklers
  2. Beneath all tiers under the highest solid shelf for CMSA and ESFR sprinklers
The protection of open-top containers is outside the scope of Chapter 17. (See Section C.12.)
The number of sprinklers and the pipe sizing on a line of sprinklers in racks shall be restricted only by hydraulic calculations and not by any piping schedule.
When in-rack sprinklers are necessary to protect a higher hazard commodity that occupies only a portion of the length of a rack, in-rack sprinklers shall be extended a minimum of 8 ft (2.4 m) or one bay, whichever is greater, in each direction along the rack on either side of the higher hazard.
The in-rack sprinklers protecting the higher hazard shall not be required to be extended across the aisle.
Where a storage rack, due to its length, requires less than the number of in-rack sprinklers specified, only those in-rack sprinklers in a single rack need to be included in the calculation.
Where in-rack sprinklers are installed in longitudinal flues, they shall be located at an intersection of transverse and longitudinal flues while not exceeding the maximum spacing rules.
Where distances between transverse flues exceed the maximum allowable distances, sprinklers shall be installed at the intersection of the transverse and longitudinal flues, and additional sprinklers shall be installed between transverse flues to meet the maximum distance rules.
Where no transverse flues exist, in-rack sprinklers shall not exceed the maximum spacing rules.
For storage over 25 ft in height, in-rack sprinklers in longitudinal flues shall be installed with the deflector located at or below the bottom of horizontal load beams or above or below other adjacent horizontal rack members, and such in-rack sprinklers shall be a minimum of 3 in. (76 mm) radially from the side of the rack uprights.
Horizontal barriers used in conjunction with in-rack sprinklers to impede vertical fire development shall be constructed of sheet metal, wood, or similar material and shall extend the full length and depth of the rack.
Barriers shall be fitted within 2 in. (50 mm) horizontally around rack uprights.
In double- and multiple-row open racks, a longitudinal (back-to-back clearance between loads) flue space shall not be required.
Nominal 6 in. (150 mm) transverse flue spaces between loads and at rack uprights shall be maintained in single-, double-, and multiple-row racks.
Random variations in the width of flue spaces or in their vertical alignment shall be permitted.
Nominal 6 in. (150 mm) longitudinal flue spaces shall be provided in double-row racks.
Nominal 6 in. (150 mm) transverse flue spaces between loads and at rack uprights shall be maintained in single-, double-, and multiple-row racks.
Random variations in the width of the flue spaces or in their vertical alignment shall be permitted.
For the storage of Group A plastics stored 5 ft (1.5 m) or less in height, the sprinkler design criteria for miscellaneous storage specified in Chapter 13 shall be used.
For storage 5 ft (1.5 m) or less in height that does not meet the definition of Miscellaneous Storage that is on solid shelf racks, in-rack sprinklers shall be provided in accordance with 17.1.5, and ceiling sprinkler protection shall be provided in accordance with Chapter 13.
For Group A plastic commodities in cartons, encapsulated or nonencapsulated in single-, double-, and multiple-row racks and with a clearance to ceiling up to and including 10 ft. (3.1 m), ceiling sprinkler water demand in terms of density [gpm/ft2 (mm/min)] and area of operation [ft2 (m2)] shall be selected from Figure 17.2.1.2.1(a) through Figure 17.2.1.2.1(f).

Note: Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately 18 in. (450 mm) up to 10 ft (3.0 m). Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.0 m) apart vertically.

FIGURE 17.2.1.2.1(a) Storage 5 ft to 10 ft (1.5 m to 3.0 m) in Height with Up to 10 ft (3.0 m) Clearance to Ceiling.

Notes:

  1. Single level of in-rack sprinklers [K-5.6 (80) or K-8.0 (115) operating at 15 psi (1.0 bar) minimum) installed as indicated in the transverse flue spaces.
  2. Where sprinklers listed for storage use are installed at the ceiling only and the ceiling height in the protected area does not exceed 22 ft (6.7 m) and a minimum clearance of 5 ft (1.5 m) and the storage height does not exceed 15 ft (4.6 m), the ceiling sprinkler discharge criteria shall be permitted to be reduced to 0.45 gpm/ft2 per 2000 ft2 (18.3 mm/min per 186 m2).
  3. Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately 18 in. (450 mm) up to 10 ft (3.0 m). Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.0 m) apart vertically.

FIGURE 17.2.1.2.1(b) Storage 15 ft (4.6 m) in Height with Up to 10 ft (3.0 m) Clearance to Ceiling.

Notes:

1. Single level of in-rack sprinklers [K-5.6 (80) or K-8.0 (115) operating at 15 psi (1.0 bar) minimum] installed as indicated in the transverse flue spaces.

2. Ceiling-only protection is not permitted for this storage configuration except where K-11.2 or larger spray sprinklers listed for storage use are installed. In-rack sprinklers are not required, provided the ceiling sprinkler discharge criterion is increased to 0.6 gpm/ft2 (24 mm/min) over 2000 ft2 (186 m2).

3. Single level of in-rack sprinklers [K-8.0 (115) operating at 15 psi (1.0 bar) minimum or K-5.6 (80) operating at 30 psi (2.1 bar) minimum] installed on 4 ft to 5 ft (1.2 m to 1.5 m) spacings located, as indicated, in the longitudinal flue space at the intersection of every transverse flue space.

4. Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately 18 in. (450 mm) up to 10 ft (3.0 m). Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.0 m) apart vertically.

FIGURE 17.2.1.2.1(c) Storage 20 ft (6.1 m) in Height with <5 ft (1.5 m) Clearance to Ceiling

Notes:

  1. Single level of in-rack sprinklers [K-5.6 (80) or K-8.0 (115) operating at 15 psi (1.0 bar) minimum] installed as indicated in the transverse flue spaces.
  2. Ceiling-only protection shall not be permitted for this storage configuration except where K-11.2 or larger orifice spray sprinklers listed for storage use are installed. In-rack sprinklers shall not be required, provided the ceiling sprinkler discharge criterion is increased to 0.6 gpm/ft2 (24.4 mm/min) over 2000 ft2 (186 m2) and the ceiling height in the protected area does not exceed 27 ft (8.2 m).
  3. Two levels of in-rack sprinklers [K-5.6 (80) or K-8.0 (115) operating at 15 psi (1.0 bar) minimum] installed as indicated and staggered in the transverse flue space.
  4. Single level of in-rack sprinklers [K-8 (115) operating at 15 psi (1.0 bar) or K-5.6 (80) operating at 30 psi (2.1 bar) minimum] installed on 4 ft to 5 ft (1.2 m to 1.5 m) spacings located, as indicated, in the longitudinal flue space at the intersection of every transverse flue space.
  5. Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately 18 in. (450 mm) up to 10 ft (3.0 m). Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.0 m) apart vertically.

FIGURE 17.2.1.2.1(d) Storage 20 ft (6.1 m) in Height with 5 ft to 10 ft (1.5 m to 3.0 m) Clearance to Ceiling.

Notes:

  1. Single level of in-rack sprinklers [K-8.0 (115) operating at 15 psi (1.0 bar) minimum or K-5.6 (80) operating at 30 psi (2.1 bar) minimum] installed on 4 ft to 5 ft (1.2 m to 1.5 m) spacings located, as indicated, in the longitudinal flue space at the intersection of every transverse flue space.
  2. Ceiling-only protection shall not be permitted for this storage configuration except where K-16.8 spray sprinklers listed for storage use are installed. In-rack sprinklers shall not be required, provided the ceiling sprinkler discharge criterion is increased to 0.8 gpm/ft2 (32.6 mm/min) over 2000 ft2 (186 m2) for wet systems and 4500 ft2 (418 m2) for dry systems and the ceiling height in the protected area does not exceed 30 ft (9.1 m).
  3. Two levels of in-rack sprinklers [K-5.6 (80) or K-8.0 (115) operating at 15 psi (1.0 bar) minimum] installed as indicated and staggered in the transverse flue space.
  4. Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately 18 in. (450 mm) up to 10 ft (3.0 m). Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.0 m) apart vertically.

FIGURE 17.2.1.2.1(e) Storage 25 ft (7.6 m) in Height with <5 ft (1.5 m) Clearance to Ceiling. (See Note 2.)

Notes:

  1. Two levels of in-rack sprinklers [K-5.6 (80) or K-8.0 (115) operating at 15 psi (1.0 bar) minimum] installed on 8 ft to 10 ft (2.4 m to 3.0 m) spacings located as indicated and staggered in the transverse flue space.
  2. Ceiling-only protection shall not be permitted for this storage configuration except where K-16.8 spray sprinklers listed for storage use are installed. In-rack sprinklers shall not be required, provided the ceiling sprinkler discharge criterion is increased to 0.8 gpm/ft2 (32.6 mm/min) over 2000 ft2 (186 m2) for wet systems and 4500 ft2 (418 m2) for dry systems and the ceiling height in the protected area does not exceed 30 ft (9.1 m).
  3. Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.51 m) on a side. Actual load heights can vary from approximately 18 in. (450 mm) up to 10 ft (3.0 m). Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.0 m) apart vertically.

FIGURE 17.2.1.2.1(f) Storage 25 ft (7.6 m) in Height with 5 ft to 10 ft (1.5 m to 3.0 m) Clearance to Ceiling. (See Note 2.)

Linear interpolation of design densities and areas of application shall be permitted between storage heights with the same clearance to ceiling.
No interpolation between clearance to ceiling shall be permitted.
An option shall be selected from the appropriate Figure 17.2.1.2.1(a) through Figure 17.2.1.2.1(f) given the storage height and clearance being protected. The density/ area criteria at the top of each option shall be applied to the ceiling sprinklers and the in-rack sprinklers shown in the option (if any) shall be provided. Options that do not show multiple-row racks in the figures shall not be permitted to protect multiple-row rack storage. Notes in each figure shall be permitted to clarify options or to present additional options not shown in the figures.
For storage of Group A plastics between 5 ft and 12 ft (1.5 m and 3.7 m) in height, the installation requirements for extra hazard systems shall apply.
Exposed unexpanded Group A plastics protected with control mode density/area sprinklers shall be protected in accordance with one of the following:
  1. Maximum 10 ft (3.0 m) storage in a maximum 20 ft (6.1 m) high building with ceiling sprinklers designed for a minimum 0.8 gpm/ft2 (32.6 mm/min) density over 2500 ft2 (232 m2) and no in-rack sprinklers required as shown in Figure 17.2.1.4(a)
  2. Maximum 10 ft (3.0 m) storage in a maximum 20 ft (6.1 m) high building with ceiling sprinklers designed for a minimum 0.45 gpm/ft2 (18.3 mm/min) density over 2000 ft2 (186 m2) and one level of in-rack sprinklers required at alternate transverse flues as shown in Figure 17.2.1.4(b)
  3. Maximum 10 ft (3.0 m) storage in a maximum 20 ft (6.1 m) high building with ceiling sprinklers designed for a minimum 0.3 gpm/ft2 (12.2 mm/min) density over 2000 ft2 (186 m2) and one level of in-rack sprinklers required in every transverse flue as shown in Figure 17.2.1.4(c)
  4. Maximum 15 ft (4.6 m) storage in a maximum 25 ft (7.6 m) high building with ceiling sprinklers designed for a minimum 0.45 gpm/ft2 (18.3 mm/min) density over 2000 ft2 (186 m2) and one level of in-rack sprinklers required at alternate transverse flues as shown in Figure 17.2.1.4(d)
  5. Maximum 15 ft (4.6 m) storage in a maximum 25 ft (7.6 m) high building with ceiling sprinklers designed for a minimum 0.3 gpm/ft2 (12.2 mm/min) density over 2000 ft2 (186 m2) and one level of in-rack sprinklers required in every transverse flue as shown in Figure 17.2.1.4(e)
  6. Maximum 20 ft (6.1 m) storage in a maximum 25 ft (7.6 m) high building with ceiling sprinklers designed for a minimum 0.6 gpm/ft2 (24.4 mm/min) density over 2000 ft2 (186 m2) and one level of in-rack sprinklers required at alternate transverse flues as shown in Figure 17.2.1.4(f)
  7. Maximum 20 ft (6.1 m) storage in a maximum 25 ft (7.6 m) high building with ceiling sprinklers designed for a minimum 0.45 gpm/ft2 (18.3 mm/min) density over 2000 ft2 (186 m2) and one level of in-rack sprinklers required in every transverse flue as shown in Figure 17.2.1.4(g)
  8. Maximum 20 ft (6.1 m) storage in a maximum 30 ft (9.1 m) high building with ceiling sprinklers designed for a minimum 0.8 gpm/ft2 (32.6 mm/min) density over 1500 ft2 (139 m2) and one level of in-rack sprinklers required at alternate transverse flues as shown in Figure 17.2.1.4(h)
  9. Maximum 20 ft (6.1 m) storage in a maximum 30 ft (9.1 m) high building with ceiling sprinklers designed for a minimum 0.6 gpm/ft2 (24.4 mm/min) density over 1500 ft2 (139 m2) and one level of in-rack sprinklers required in every transverse flue as shown in Figure 17.2.1.4 (i)
  10. Maximum 20 ft (6.1 m) storage in a maximum 30 ft (9.1 m) high building with ceiling sprinklers designed for a minimum 0.3 gpm/ft2 (12.2 mm/min) density over 2000 ft2 (186 m2) and two levels of in-rack sprinklers required in every transverse flue as shown in Figure 17.2.1.4(j)
  11. Maximum 25 ft (7.6 m) storage in a maximum 35 ft (11 m) high building with ceiling sprinklers designed for a minimum 0.8 gpm/ft2 (32.6 mm/min) density over 1500 ft2 (139 m2) and one level of in-rack sprinklers required in every transverse flue as shown in Figure 17.2.1.4(k)
  12. Maximum 25 ft (7.6 m) storage in a maximum 35 ft (11 m) high building with ceiling sprinklers designed for a minimum 0.3 gpm/ft2 (12.2 mm/min) density over 2000 ft2 (186 m2) and two levels of in-rack sprinklers required in every transverse flue as shown in Figure 17.2.1.4(l)

Note: Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately 18 in. to 10 ft (450 mm to 3.0 m). Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.0 m) apart vertically.

FIGURE 17.2.1.4(a) Exposed Nonexpanded Group A Plastic Up to 10 ft (3.0 m) in Height in Up to a 20 ft (6.1 m) High Building with No In-Rack Sprinklers.

Note: Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately 18 in. to 10 ft (450 mm to 3.0 m). Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.0 m) apart vertically.

FIGURE 17.2.1.4(b) Exposed Nonexpanded Group A Plastic Up to 10 ft (3.0 m) in Height in Up to a 20 ft (6.1 m) High Building with One Level of In-Rack Sprinklers.

Note: Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately 18 in. to 10 ft (450 mm to 3.0 m). Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.0 m) apart vertically.

FIGURE 17.2.1.4(c) Exposed Nonexpanded Group A Plastics Up to 10 ft (3.0 m) in Height in Up to a 20 ft (6.1 m) High Building with One Level of Closely Spaced In-Rack Sprinklers.

Note: Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately 18 in. to 10 ft (450 mm to 3.0 m). Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.0 m) apart vertically.

FIGURE 17.2.1.4(d) Exposed Nonexpanded Group A Plastics Up to 15 ft (4.6 m) in Height in Up to a 25 ft (7.6 m) High Building with One Level of In-Rack Sprinklers.

Note: Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately 18 in. to 10 ft (450 mm to 3.0 m). Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.0 m) apart vertically.

FIGURE 17.2.1.4(e) Exposed Nonexpanded Group A Plastics Up to 15 ft (4.6 m) in Height in Up to a 25 ft (7.6 m) High Building with One Level of Closely Spaced In-Rack Sprinklers.

Note: Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately 18 in. to 10 ft (450 mm to 3.0 m). Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.0 m) apart vertically.

FIGURE 17.2.1.4(f) Exposed Nonexpanded Group A Plastics Up to 20 ft (6.1 m) in Height in Up to a 25 ft (7.6 m) High Building with One Level of In-Rack Sprinklers.

Note: Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately 18 in. to 10 ft (450 mm to 3.0 m). Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.0 m) apart vertically.

FIGURE 17.2.1.4(g) Exposed Nonexpanded Group A Plastics Up to 20 ft (6.1 m) in Height in Up to a 25 ft (7.6 m) High Building with One Level of Closely Spaced In-Rack Sprinklers.

Note: Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately 18 in. to 10 ft (450 mm to 3.0 m). Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.0 m) apart vertically.

FIGURE 17.2.1.4(h) Exposed Nonexpanded Group A Plastics Up to 20 ft (6.1 m) in Height in Up to a 30 ft (9.1 m) High Building with One Level of In-Rack Sprinklers.

Note: Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately 18 in. to 10 ft (450 mm to 3.0 m). Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.0 m) apart vertically.

FIGURE 17.2.1.4(i) Exposed Nonexpanded Group A Plastics Up to 20 ft (6.1 m) in Height in Up to a 30 ft (9.1 m) High Building with One Level of Closely Spaced In-Rack Sprinklers.

Note: Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately 18 in. to 10 ft (450 mm to 3.0 m). Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.0 m) apart vertically.

FIGURE 17.2.1.4(j) Exposed Nonexpanded Group A Plastics Up to 20 ft (6.1 m) in Height in Up to a 30 ft (9.1 m) High Building with Two Levels of Closely Spaced In-Rack Sprinklers.

Note: Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately 18 in. to 10 ft (450 mm to 3.0 m). Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.0 m) apart vertically.

FIGURE 17.2.1.4(k) Exposed Nonexpanded Group A Plastics Up to 25 ft (7.6 m) in Height in Up to a 35 ft (10.7 m) High Building with One Level of Closely Spaced In-Rack Sprinklers.

Note: Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately 18 in. to 10 ft (450 mm to 3.0 m). Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.0 m) apart vertically.

FIGURE 17.2.1.4(l) Exposed Nonexpanded Group A Plastics Up to 25 ft (7.6 m) in Height in Up to a 35 ft (10.7 m) High Building with Two Levels of Closely Spaced In-Rack Sprinklers.

The minimum of 6 in. (150 mm) vertical clear space shall be maintained between the sprinkler deflectors and the top of a tier of storage.

(A) Sprinkler discharge shall not be obstructed by horizontal rack members.

The spacing of in-rack sprinklers shall be in accordance with Figure 17.2.1.2.1(a) through Figure 17.2.1.2.1(f).
In-rack sprinklers shall be located at an intersection of transverse and longitudinal flues while not exceeding the maximum spacing rules.
Where distances between transverse flues exceed the maximum allowable distances, sprinklers shall be installed at the intersection of the transverse and longitudinal flues, and additional sprinklers shall be installed between transverse flues to meet the maximum distance rules.
Where no transverse flues exist, in-rack sprinklers shall not exceed the maximum spacing rules.
The water demand for sprinklers installed in racks shall be based on simultaneous operation of the most hydraulically remote sprinklers as follows:
  1. Eight sprinklers where only one level is installed in racks
  2. Fourteen sprinklers (seven on each top two levels) where more than one level is installed in racks
Sprinklers in racks shall discharge at not less than 15 psi (1.0 bar) for all classes of commodities. (See Section C.19.)
Protection of single-, double-, and multiple-row rack storage for unexpanded Group A plastic commodities shall be in accordance with Table 17.2.2.1.

Table 17.2.2.1 CMSA Sprinkler Design Criteria for Single-, Double-, and Multiple-Row Racks of Group A Plastic Commodities Stored Up and Including 25 ft (7.6 m) in Height

Storage Arrangement Commodity Class Maximum Storage Height Maximum Ceiling/Roof Height K-Factor/Orientation Type of System Number of Design Sprinklers Minimum Operating Pressure
ft m ft m psi bar
Single-, double-, and multiple-row racks (no open-top containers) Cartoned nonexpanded plastics 20 6.1 25 7.6 11.2 (160) Upright Wet 15 50 3.4
16.8 (240) Upright Wet 15 22 1.5
19.6 (280) Pendent Wet 15 16 1.1
30 9.1 11.2 (160) Upright Wet 30 50 3.4
Wet 20 75 5.2
16.8 (240) Upright Wet 15* 22 1.5
19.6 (280) Pendent Wet 15 16 1.1
25 7.6 30 9.1 11.2 (160) Upright Wet 15 + 1 level of in-rack 50 3.4
16.8 (240) Upright Wet 15* 22 1.5
19.6 (280) Pendent Wet 15 16 1.1
25 7.6 35 11 11.2 (160) Upright Wet 30 + 1 level of in-rack 50 3.4
Wet 20 + 1 level of in-rack 75 5.2
16.8 (240) Upright Wet 30 + 1 level of in-rack 22 1.5
Wet 20 + 1 level of in-rack 35 2.4
19.6 (280) Pendent Wet 15 25 1.7
Exposed nonexpanded plastics 20 6.1 25 7.6 11.2 (160) Upright Wet 15 50 3.4
16.8 (240) Upright Wet 15 22 1.5
20 6.1 30 9.1 11.2 (160) Upright Wet 30 50 3.4
Wet 20 75 5.2
16.8 (240) Upright Wet 15* 22 1.5
25 7.6 30 9.1 11.2 (160) Upright Wet 15 + 1 level of in-rack 50 3.4
16.8 (240) Upright Wet 15* 22 1.5
25 7.6 35 11 11.2 (160) Upright Wet 30 + 1 level of in-rack 50 3.4
Wet 20 + 1 level of in-rack 75 5.2
16.8 (240) Upright Wet 30 + 1 level of in-rack 22 1.5
Wet 20 + 1 level of in-rack 35 2.4
*Limited to single- and double-row racks with minimum 8 ft (2.4 m) aisles.
CMSA sprinklers shall not be permitted to protect storage on solid shelf racks unless the solid shelf racks are protected with in-rack sprinklers in accordance with 17.1.5.
Where solid shelves are used, in-rack sprinklers shall be installed in every level below the highest solid shelf.
Protection shall be provided as specified in Table 17.2.2.1 or appropriate NFPA standards in terms of minimum operating pressure and the number of sprinklers to be included in the design area.
Where CMSA sprinklers are installed under open wood joist construction, firestopping in accordance with 17.2.2.3.2 shall be provided or the minimum operating pressure of the sprinklers 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.
Where each joist channel of open wood joist construction is fully firestopped to its full depth at intervals not exceeding 20 ft (6.1 m), the lower pressures specified in Table 17.2.2.1 shall be permitted to be used.
For the purpose of using Table 17.2.2.1, preaction systems shall be classified as dry pipe systems.
Building steel shall not require special protection where Table 17.2.2.1 is applied as appropriate for the storage configuration.
In-rack sprinklers shall be installed at the first tier level at or above one-half of the storage height.
The minimum of 6 in. (150 mm) vertical clear space shall be maintained between the sprinkler deflectors and the top of a tier of storage.

(A) Sprinkler discharge shall not be obstructed by horizontal rack members.

In-rack sprinklers shall be located at an intersection of transverse and longitudinal flues.
The maximum horizontal distance between in-rack sprinklers shall be 5 ft (1.5 m).
Where distances between transverse flues exceed the maximum allowable distances, sprinklers shall be installed at the intersection of the transverse and longitudinal flues, and additional sprinklers shall be installed between transverse flues to meet the maximum distance rules.
Where no transverse flues exist, in-rack sprinklers shall not exceed the maximum spacing rules.
The water demand for sprinklers installed in racks shall be based on simultaneous operation of the most hydraulically remote eight sprinklers.
Sprinklers in racks shall discharge at not less than 15 psi (1.0 bar) for all classes of commodities. (See Section C.19.)
Protection of single-, double-, and multiple-row rack storage of cartoned or exposed unexpanded Group A plastic and cartoned expanded Group A plastic shall be in accordance with Table 17.2.3.1.

Table 17.2.3.1 ESFR Protection of Rack Storage of Group A Plastic Commodities Stored Up to and Including 25 ft (7.6 m) in Height

Storage Arrangement Commodity Maximum Storage Height Maximum Ceiling/Roof Height Nominal K-Factor Orientation Minimum Operating Pressure In-Rack Sprinkler Requirements
ft m ft m psi bar
Single-, double-, and multiple-row racks (no open-top containers) Cartoned nonexpanded 20 6.1 25 7.6 14.0
(200)
Upright/pendent 50 3.4 No
16.8
(240)
Upright/pendent 35 2.4 No
22.4
(320)
Pendent 25 1.7 No
25.2
(360)
Pendent 15 1.0 No
30 9.1 14.0
(200)
Upright/pendent 50 3.4 No
16.8
(240)
Upright/pendent 35 2.4 No
22.4
(320)
Pendent 25 1.7 No
25.2
(360)
Pendent 15 1.0 No
35 11 14.0
(200)
Upright/pendent 75 5.2 No
16.8
(240)
Upright/pendent 52 3.6 No
22.4
(320)
Pendent 35 2.4 No
25.2
(360)
Pendent 20 1.4 No
40 12 16.8
(240)
Pendent 52 3.6 No
22.4
(320)
Pendent 40 2.7 No
25.2
(360)
Pendent 25 1.7 No
45 14 14.0
(200)
Pendent 90 6.2 Yes
16.8
(240)
Pendent 63 4.3 Yes
22.4
(320)
Pendent 40 2.7 No
25.2
(360)
Pendent 40 2.7 No
25 7.6 30 9.1 14.0
(200)
Upright/pendent 50 3.4 No
16.8
(240)
Upright/pendent 35 2.4 No
22.4
(320)
Pendent 25 1.7 No
25.2
(360)
Pendent 15 1.0 No
32 10 14.0
(200)
Upright/pendent 60 4.1 No
16.8
(240)
Upright/pendent 42 2.9 No
35 11 14.0
(200)
Upright/pendent 75 5.2 No
16.8
(240)
Upright/pendent 52 3.6 No
22.4
(320)
Pendent 35 2.4 No
25.2
(360)
Pendent 20 1.4 No
40 12 16.8
(240)
Pendent 52 3.6 No
22.4
(320)
Pendent 40 2.7 No
25.2
(360)
Pendent 25 1.7 No
45 14 14.0
(200)
Pendent 90 6.2 Yes
16.8
(240)
Pendent 63 4.3 Yes
22.4
(320)
Pendent 40 2.7 No
25.2
(360)
Pendent 40 2.7 No
Exposed nonexpanded 20 6.1 25 7.6 14.0
(200)
Pendent 50 3.4 No
16.8
(240)
Pendent 35 2.4 No
30 9.1 14.0
(200)
Pendent 50 3.4 No
16.8
(240)
Pendent 35 2.4 No
35 11 14.0
(200)
Pendent 75 5.2 No
16.8
(240)
Pendent 52 3.6 No
40 12 16.8
(240)
Pendent 52 3.6 No
45 14 14.0
(200)
Pendent 90 6.2 Yes
16.8
(240)
Pendent 63 4.3 Yes
25 7.6 30 9.1 14.0
(200)
Pendent 50 3.4 No
16.8
(240)
Pendent 35 2.4 No
32 10 14.0
(200)
Pendent 60 4.1 No
16.8
(240)
Pendent 42 2.9 No
35 11 14.0
(200)
Pendent 75 5.2 No
16.8
(240)
Pendent 52 3.6 No
40 12 16.8
(240)
Pendent 52 3.6 No
22.4
(320)
Pendent 50 3.4 No
25.2
(360)
Pendent 50 3.4 No
45 14 14.0
(200)
Pendent 90 6.2 Yes
16.8
(240)
Pendent 63 4.3 Yes
Cartoned expanded 20 6.1 25 7.6 14.0
(200)
Upright/pendent 50 3.4 No
16.8
(240)
Upright/pendent 35 2.4 No
30 9.1 14.0
(200)
Upright/pendent 50 3.4 No
16.8
(240)
Upright/pendent 35 2.4 No
25 7.6 30 9.1 14.0
(200)
Upright/pendent 50 3.4 No
16.8
(240)
Upright/pendent 35 2.4 No
32 10 14.0
(200)
Pendent 60 4.1 No
16.8
(240)
Upright/pendent 42 2.9 No
ESFR protection as defined shall not apply to the following:
  1. Rack storage involving solid shelves, except as permitted by 17.2.3.1.2
  2. Rack storage involving open-top cartons or containers
ESFR sprinklers shall not be permitted to protect storage on solid shelf racks unless the solid shelf racks are protected with in-rack sprinklers in accordance with 17.1.5.
Where solid shelves are used, in-rack sprinklers shall be installed in every level below the highest solid shelf.
ESFR sprinkler systems shall be designed such that the minimum operating pressure is not less than that indicated in Table 17.2.3.1 for type of storage, commodity, storage height, and building height involved.
The design area shall consist of the most hydraulically demanding area of 12 sprinklers, consisting of four sprinklers on each of three branch lines.
Where required by Table 17.2.3.1, in-rack sprinklers shall be installed at the first tier level at or above one-half of the storage height.
In-rack sprinklers shall be K-8.0 (115) or K-11.2 (160) quick-response, ordinary-temperature sprinklers.
The minimum of 6 in. (150 mm) vertical clear space shall be maintained between the sprinkler deflectors and the top of a tier of storage.

(A) Sprinkler discharge shall not be obstructed by horizontal rack members.

The maximum horizontal distance between in-rack sprinklers shall be 5 ft (1.5 m).
In-rack sprinklers shall be located at an intersection of transverse and longitudinal flues while not exceeding the maximum spacing rules.
Where distances between transverse flues exceed the maximum allowable distances, sprinklers shall be installed at the intersection of the transverse and longitudinal flues, and additional sprinklers shall be installed between transverse flues to meet the maximum distance rules.
Where no transverse flues exist, in-rack sprinklers shall not exceed the maximum spacing rules.
The water demand for sprinklers installed in racks shall be based on simultaneous operation of the most hydraulically remote eight sprinklers.
Each of the in-rack sprinklers described in 17.2.3.4.8 shall discharge at a minimum of 60 gpm (227 L/min).
Protection of single-, double-, and multiple-row rack storage of exposed expanded Group A plastics shall be permitted to be in accordance with 17.2.3.5.2 through 17.2.3.5.8.
The maximum storage height shall be 25 ft (9.1 m).
The maximum ceiling height shall be 40 ft (12.2 m).
Sprinklers shall be intermediate temperature-rated ESFR pendent sprinklers with a nominal K-factor of K-25.2 (360).
The design area shall consist of the most hydraulically demanding area of 12 sprinklers.
Subsection 17.2.3.5.6 was revised by a tentative interim amendment (TIA). See page 1.
The minimum operating pressure shall be either 30 psi (2.0 bar) or 60 psi (4.1 bar) based upon the applicable storage and ceiling height for the installation as follows:
  1. 30 psi (2.0 bar) for storage heights up to 25 ft (7.6 m) with a maximum ceiling height of 30 ft (9.1 m)
  2. 60 psi (4.1 bar) for storage heights up to 25 ft (7.6 m) with a maximum ceiling height of 40 ft (12.2 m)
The minimum aisle width shall be 8 ft (2.4 m).
The rack shall have a solid vertical barrier of 3/8 in. (9.5 mm) plywood or particleboard, 22 gauge sheet metal, or equivalent, from face of rack to face of rack, spaced at a maximum of 16.5 ft (5.0 m) intervals.
The vertical barrier shall extend from a maximum of 4 in. (102 mm) above the floor to the maximum storage height.
The plan area of storage between vertical barriers and aisles shall not exceed 124 ft2 (11.52 m2).
The vertical barrier shall extend across the longitudinal flue.
Commodity shall be permitted to extend a nominal 4 in. (102 mm) beyond the vertical barrier at the aisle.
Slatted rack shelves shall be considered equivalent to solid rack shelves where the shelving is not considered open rack shelving or where the requirements of 17.2.4.1 are not met. (See Section C.20.)
A wet pipe system that is designed to provide a minimum of 0.6 gpm/ft2 (24.4 mm/min) density over a minimum area of 2000 ft2 (186 m2) or K-14.0 (200) ESFR sprinklers operating at a minimum of 50 psi (3.4 bar), K-16.8 (240) sprinklers operating at a minimum of 32 psi (2.2 bar), or K-25.2 (360) ESFR sprinklers operating at a minimum of 15 psi (1.0 bar) shall be permitted to protect single- and double-row racks with slatted rack shelving racks where all of the following conditions are met:
  1. Sprinklers shall be K-l1.2 (160), K-14.0 (200), or K-16.8 (240) orifice spray sprinklers with a temperature rating of ordinary, intermediate, or high and shall be listed for storage occupancies or shall be K-14.0 (200), K-16.8 (240), or K-25.2 (360) ESFR.
  2. The protected commodities shall be limited to Class I through Class IV, Group B plastics, Group C plastics, cartoned (expanded and unexpanded) Group A plastics, and exposed (unexpanded) Group A plastics.
  3. Slats in slatted rack shelving shall be a minimum nominal 2 in. (50 mm) thick by maximum nominal 6 in. (150 mm) wide with the slats held in place by spacers that maintain a minimum 2 in. (50 mm) opening between each slat.
  4. Where K-l1.2 (160), K-14.0 (200), or K-16.8 (240) orifice sprinklers are used, there shall be no slatted shelf levels in the rack above 12 ft (3.7 m). Open rack shelving using wire mesh shall be permitted for shelf levels above 12 ft (3.7 m).
  5. Transverse flue spaces at least 3 in. (75 mm) wide shall be provided at least every 10 ft (3.0 m) horizontally.
  6. Longitudinal flue spaces at least 6 in. (150 mm) wide shall be provided for double-row racks. Longitudinal flue spaces shall not be required when ESFR sprinklers are used.
  7. The aisle widths shall be at least 71/2 ft (2.3 m).
  8. The maximum roof height shall be 27 ft (8.2 m) or 30 ft (9.1 m) where ESFR sprinklers are used.
  9. The maximum storage height shall be 20 ft (6.1 m).
  10. Solid plywood or similar materials shall not be placed on the slatted shelves so that they block the 2 in. (50 mm) spaces between slats, nor shall they be placed on the wire mesh shelves.
Protection of Group A plastics in cartons, expanded or unexpanded, whether encapsulated or nonencapsulated and with a clearance to ceiling up to and including 10 ft (3.1 m), shall be permitted using control mode density/area sprinklers in accordance with 17.3.1.
Protection of Group A plastics that are exposed and unexpanded, whether encapsulated or nonencapsulated racks and with a clearance to ceiling up to and including 10 ft (3.1 m), shall be permitted only using in-rack sprinkler arrangements that are specifically permitted to be used with exposed unexpanded plastics.
Ceiling Sprinkler Water Demand. For Group A plastic commodities, encapsulated or nonencapsulated, ceiling sprinkler water demand in terms of density [gpm/ft2 (mm/ min) ] and area of operation [ft2 (m2) ] shall be selected from Table 17.3.1.3.

Table 17.3.1.3 Control Mode Density/Area Sprinkler Discharge Criteria for Single-, Double-, and Multiple-Row Racks of Group A Plastic Commodities with Storage Over 25 ft (7.6 m) in Height

Storage Height Above Top Level In-Rack Sprinklers Ceiling Sprinklers Density
ft m gpm/ft2 over ft2 mm/min over m2
5 or less 1.5 or less 0.30/2000 12.2/186
Over 5 up to 10 Over 1.5 up to 3.0 0.45/2000 18.3/186
For protection of cartoned storage of Group A plastics, expanded or unexpanded, whether encapsulated or nonencapsulated, on single-row racks, in-rack sprinklers shall be arranged in accordance with one of the options in Figure 17.3.1.4(a) through Figure 17.3.1.4(c) or Figure 17.3.1.7. The highest level of in-rack sprinklers shall be not more than 10 ft (3.0 m) below the top of storage.

Note: Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately 18 in. (450 mm) up to 10 ft (3.0 m). Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.0 m) apart vertically.

FIGURE 17.3.1.4(a) In-Rack Sprinkler Arrangement, Group A Plastic Commodities, Single-Row Racks, Storage Height Over 25 ft (7.6 m) — Option 1.

Note: Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately 18 in. (450 mm) up to 10 ft (3.0 m). Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.0 m) apart vertically.

FIGURE 17.3.1.4(b) In-Rack Sprinkler Arrangement, Group A Plastic Commodities, Single-Row Racks, Storage Height Over 25 ft (7.6 m) — Option 2.

Note: Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately 18 in. (450 mm) up to 10 ft (3.0 m). Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.0 m) apart vertically.

FIGURE 17.3.1.4(c) In-Rack Sprinkler Arrangement, Group A Plastic Commodities, Single-Row Racks, Storage Height Over 25 ft (7.6 m) — Option 3.

For protection of cartoned storage of Group A plastics, expanded or unexpanded, whether encapsulated or nonencapsulated, on double-row racks, in-rack sprinklers shall be arranged in accordance with one of the double-row rack options in Figure 17.3.1.5(a), Figure 17.3.1.5(b), or Figure 17.3.1.7. The highest level of in-rack sprinklers shall be not more than 10 ft (3.0 m) below the top of storage.

Notes:

  1. Sprinklers and barriers labeled 1 shall be required where loads labeled A or B represent top of storage.
  2. Sprinklers labeled 1 and 2 and barriers labeled 1 shall be required where loads labeled C represent top of storage.
  3. Sprinklers and barriers labeled 1 and 3 shall be required where loads labeled D or E represent top of storage.
  4. For storage higher than represented by loads labeled E, the cycle defined by Notes 2 and 3 is repeated.
  5. Symbol Δ or × indicates face sprinklers on vertical or horizontal stagger.
  6. Symbol o indicates longitudinal flue space sprinklers.
  7. Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately 18 in. (450 mm) up to 10 ft (3.0 m). Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.0 m) apart vertically.

FIGURE 17.3.1.5(a) In-Rack Sprinkler Arrangement, Group A Plastic Commodities, Storage Height Over 25 ft (7.6 m) — Option 1.

Notes:

  1. Sprinklers labeled 1 shall be required where loads labeled A or B represent top of storage.
  2. Sprinklers labeled 1 and 2 shall be required where loads labeled C represent top of storage.
  3. Sprinklers labeled 1 and 3 shall be required where loads labeled D or E represent top of storage.
  4. For storage higher than loads labeled F, the cycle defined by Notes 2 and 3 is repeated.
  5. Symbol × indicates face and in-rack sprinklers.
  6. Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately 18 in. (450 mm) up to 10 ft (3.0 m). Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.0 m) apart vertically.

FIGURE 17.3.1.5(b) In-Rack Sprinkler Arrangement, Group A Plastic Commodities, Storage Height Over 25 ft (7.6 m) — Option 2.

Where a single-row rack of cartoned Group A plastic storage is mixed with double-row racks of cartoned Group A plastic storage, either Figure 17.3.1.5(a) or Figure 17.3.1.5(b) shall be permitted to be used in accordance with the corresponding storage height. The highest level of in-rack sprinklers shall be not more than 10 ft (3.0 m) below the top of storage.
For protection of storage of exposed unexpanded Group A plastics, whether encapsulated or nonencapsulated, on single- racks or double-row racks, in-rack sprinklers shall be arranged in accordance with Figure 17.3.1.7. The highest level of in-rack sprinklers shall be not more than 10 ft (3.0 m) below the top of storage. Where this figure is used, aisles shall be at least 4 ft (1.2 m) wide and the ceiling sprinklers shall be designed for a minimum discharge density of 0.45 gpm/ft2 over 2000 ft2 (18.3 mm/min over 186 m2).

FIGURE 17.3.1.7 In-Rack Sprinkler Arrangement, Cartoned Expanded and Nonexpanded Group A Plastic and Exposed Non- expanded Group A Plastic Commodities, Single- and Double-Row Racks, Storage Height Over 25 ft (7.6 m).

For protection of storage of exposed unexpanded Group A plastics, whether encapsulated or nonencapsulated, or cartoned Group A plastics, expanded or unexpanded, whether encapsulated or nonencapsulated, on multiple-row racks, in-rack sprinklers shall be arranged in accordance with one of the options in Figure 17.3.1.8(a) through Figure 17.3.1.8(f). The highest level of in-rack sprinklers shall be not more than 10 ft (3.0 m) below the top of storage.

Note: Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately 18 in. (450 mm) up to 10 ft (3.0 m). Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.0 m) apart vertically.

FIGURE 17.3.1.8(a) In-Rack Sprinkler Arrangement, Cartoned Group A Plastic and Exposed Nonexpanded Group A Plastic, Multiple-Row Racks, Storage Height Over 25 ft (7.6 m) — Option 1 [10 ft (3.0 m) Maximum Spacing].

Note: Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately 18 in. (450 mm) up to 10 ft (3.0 m). Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.0 m) apart vertically.

FIGURE 17.3.1.8(b) In-Rack Sprinkler Arrangement, Cartoned Group A Plastic and Exposed Nonexpanded Group A Plastic, Multiple-Row Racks, Storage Height Over 25 ft (7.6 m) — Option 2 [10 ft (3.0) m) Maximum Spacing].

Note: Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately 18 in. (450 mm) up to 10 ft (3.0 m). Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.0 m) apart vertically.

FIGURE 17.3.1.8(c) In-Rack Sprinkler Arrangement, Cartoned Group A Plastic and Exposed Nonexpanded Group A Plastic, Multiple-Row Racks, Storage Height Over 25 ft (7.6 m) — Option 1 [5 ft (1.5 m) Maximum Spacing].

Note: Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately 18 in. (450 mm) up to 10 ft (3.0 m). Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.0 m) apart vertically.

FIGURE 17.3.1.8(d) In-Rack Sprinkler Arrangement, Cartoned Group A Plastic and Uncartoned Unexpanded Group A Plastic, Multiple-Row Racks, Storage Height Over 25 ft (7.6 m) — Option 2 [5 ft (1.5 m) Maximum Spacing].

Note: Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately 18 in. (450 mm) up to 10 ft (3.0 m). Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.0 m) apart vertically.

FIGURE 17.3.1.8(e) In-Rack Sprinkler Arrangement, Cartoned Group A Plastic and Exposed Nonexpanded Group A Plastic, Multiple-Row Racks, Storage Height Over 25 ft (7.6 m) — Option 3 [5 ft (1.5 m) Maximum Spacing].

Note: Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately 18 in. (450 mm) up to 10 ft (3.0 m). Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.0 m) apart vertically.

FIGURE 17.3.1.8(f) In-Rack Sprinkler Arrangement, Cartoned Group A Plastic and Exposed Nonexpanded Group A Plastic, Multiple-Row Racks, Storage Height Over 25 ft (7.6 m) — Option 4 [5 ft (1.5 m) Maximum Spacing].

The minimum of 6 in. (150 mm) vertical clear space shall be maintained between the in-rack sprinkler deflectors and the top of a tier of storage.

(A) Sprinkler discharge shall not be obstructed by horizontal rack members.

In-rack sprinklers shall be located at an intersection of transverse and longitudinal flues while not exceeding the maximum spacing rules.
Where distances between transverse flues exceed the maximum allowable distances, sprinklers shall be installed at the intersection of the transverse and longitudinal flues, and additional sprinklers shall be installed between transverse flues to meet the maximum distance rules.
Where no transverse flues exist, in-rack sprinklers shall not exceed the maximum spacing rules.
In-rack sprinklers shall be a minimum of 3 in. (76 mm) radially from the side of the rack uprights.
Face sprinklers in such racks shall be located within the rack a minimum of 3 in. (75 mm) from rack uprights and no more than 18 in. (450 mm) from the aisle face of storage.
The water demand for sprinklers installed in racks shall be based on simultaneous operation of the most hydraulically remote sprinklers as follows:
  1. Eight sprinklers where only one level is installed in racks
  2. Fourteen sprinklers (seven on each top two levels) where more than one level is installed in racks
Sprinklers in racks shall discharge at not less than 30 gpm (115 L/min).
The minimum water supply requirements for a hydraulically designed occupancy hazard fire control sprinkler system shall be determined by adding the hose stream allowance from Table 17.3.1.17 to the water supply for sprinklers determined in Section 17.3.

Table 17.3.1.17 Hose Stream Allowance and Water Supply Duration Requirements for Rack Storage of Group A Plastics Commodities Stored Over 25 ft (7.6 m) in Height

Commodity Classification Storage Height Inside Hose Total Combined Inside and Outside Hose Duration (minutes)
ft m gpm L/min gpm L/min
Plastic >25 >7.6 0, 50, or 100 0, 190, or 380 500 1900 120
Protection of single-, double-, and multiple-row rack storage for cartoned, unexpanded Group A plastic commodities shall be in accordance with Table 17.3.2.1.

Table 17.3.2.1 CMSA Sprinkler Design Criteria for Single-, Double-, and Multiple-Row Racks of Group A Plastics Commodities Stored Over 25 ft (7.6 m) in Height

Storage Arrangement Commodity Class Maximum Storage Height Maximum Ceiling/Roof Height K-Factor/Orientation Type of System Number of Design Sprinklers Minimum Operating Pressure
ft m ft m psi bar
Single-, double-, and multiple-row racks (no open-top containers) Cartoned, unexpanded plastics 30 9.1 35 11 19.6 (280) Pendent Wet 15 25 1.7
35 10.6 40 12 19.6 (280) Pendent Wet 15 30 2.1
CMSA sprinklers shall not be permitted to protect storage on solid shelf racks unless the solid shelf racks are protected with in-rack sprinklers in accordance with 17.1.5.
Where solid shelves are used, in-rack sprinklers shall be installed in every level below the highest solid shelf.
Protection shall be provided as specified in Table 17.3.2.1 or appropriate NFPA standards in terms of minimum operating pressure and the number of sprinklers to be included in the design area.
The design area shall be a rectangular area having a dimension parallel to the branch lines at least 1.2 times the square root of the area protected by the number of sprinklers to be included in the design area. Any fractional sprinkler shall be included in the design area.
Building steel shall not require special protection where Table 17.3.2.1 is applied as appropriate for the storage configuration.
Protection of single-, double-, and multiple-row rack storage of cartoned or exposed, unexpanded Group A plastic shall be in accordance with Table 17.3.3.1.

Table 17.3.3.1 ESFR Protection of Rack Storage of Group A Plastic Commodities Stored Over 25 ft (7.6 m) in Height

Storage Arrangement Commodity Maximum Storage Height Maximum Ceiling/Roof Height Nominal K-Factor Orientation Minimum Operating Pressure In-Rack Sprinkler Requirements
ft m ft m psi bar
Single-, double-, and multiple-row racks (no open-top containers) Cartoned unexpanded 30 9.1 35 11 14.0 (200) Upright/pendent 75 5.2 No
16.8 (240) Upright/pendent 52 3.6 No
22.4 (320) Pendent 35 2.4 No
25.2 (360) Pendent 20 1.4 No
40 12 16.8 (240) Pendent 52 3.6 No
22.4 (320) Pendent 40 2.7 No
25.2 (360) Pendent 25 1.7 No
45 14 14.0 (200) Pendent 90 6.2 Yes
16.8 (240) Pendent 63 4.3 Yes
22.4 (320) Pendent 40 2.7 No
25.2 (360) Pendent 40 2.7 No
35 11 40 12 16.8 (240) Pendent 52 3.6 No
25.2 (360) Pendent 25 1.7 No
45 14 14.0 (200) Pendent 90 6.2 Yes
16.8 (240) Pendent 63 4.3 Yes
22.4 (320) Pendent 40 2.7 No
25.2 (320) Pendent 40 2.7 No
40 12 45 14 14.0 (200) Pendent 90 6.2 Yes
16.8 (240) Pendent 63 4.3 Yes
22.4 (320) Pendent 40 2.7 No
25.2 (320) Pendent 40 2.7 No
Exposed unexpanded 30 9.1 35 10.7 14.0 (200) Pendent 75 5.2 No
16.8 (240) Pendent 52 3.6 No
40 11 16.8 (240) Pendent 52 3.6 No
22.4 (320) Pendent 50 3.4 No
25.2 (320) Pendent 50 3.4 No
45 12 14.0 (200) Pendent 90 6.2 Yes
16.8 (240) Pendent 63 4.3 Yes
35 11 40 12 16.8 (240) Pendent 52 3.6 No
22.4 (320) Pendent 50 3.4 No
25.2 (360) Pendent 50 3.4 No
45 14 14.0 (200) Pendent 90 6.2 Yes
16.8 (240) Pendent 63 4.3 Yes
40 12 45 14 14.0 (200) Pendent 90 6.2 Yes
16.8 (240) Pendent 63 4.3 Yes
ESFR sprinklers shall not be permitted to protect storage on solid shelf racks unless the solid shelf racks are protected with in-rack sprinklers in accordance with 17.1.5.
Where solid shelves are used, in-rack sprinklers shall be installed in every level below the highest solid shelf.
ESFR sprinklers shall not be permitted to protect storage with open-top containers.
ESFR sprinkler systems shall be designed such that the minimum operating pressure is not less than that indicated in Table 17.3.3.1 for type of storage, commodity, storage height, and building height involved.
The design area shall consist of the most hydraulically demanding area of 12 sprinklers, consisting of four sprinklers on each of three branch lines.
Where required by Table 17.3.3.1, one level of K-8.0 (115) or K-11.2 (160) quick-response, ordinary-temperature in-rack sprinklers shall be installed at the tier level closest to but not exceeding one-half of the maximum storage height.
In-rack sprinkler hydraulic design criteria shall be the most hydraulically remote eight sprinklers at 60 gpm (230 L/min).
In-rack sprinklers shall be located at the intersection of the longitudinal and transverse flue space.
Horizontal spacing shall not be permitted to exceed 5 ft (1.5 m) intervals.
The minimum of 6 in. (150 mm) vertical clear space shall be maintained between the sprinkler deflectors and the top of a tier of storage.

(A) Sprinkler discharge shall not be obstructed by horizontal rack members.

In-rack sprinklers shall be located at an intersection of transverse and longitudinal flues while not exceeding the maximum spacing rules.
Where distances between transverse flues exceed the maximum allowable distances, sprinklers shall be installed at the intersection of the transverse and longitudinal flues, and additional sprinklers shall be installed between transverse flues to meet the maximum distance rules.
Where no transverse flues exist, in-rack sprinklers shall not exceed the maximum spacing rules.
In-rack sprinklers shall be a minimum of 3 in. (76 mm) radially from the side of the rack uprights.
Face sprinklers in such racks shall be located within the rack a minimum of 3 in. (75 mm) from rack uprights and no more than 18 in. (450 mm) from the aisle face of storage.
Protection of single-, double-, and multiple-row rack storage of exposed expanded Group A plastics shall be permitted to be in accordance with 17.3.3.5.2 through 17.3.3.5.8.
The maximum storage height shall be 35 ft (11 m).
The maximum ceiling height shall be 40 ft (12 m).
Sprinklers shall be intermediate temperature-rated ESFR pendent sprinklers with a nominal K-factor of K-25.2 (360).
The design area shall consist of the most hydraulically demanding area of 12 sprinklers.
The minimum operating pressure shall be 60 psi (4.1 bar).
The minimum aisle width shall be 8 ft (2.4 m).
The rack shall have a solid vertical barrier of 3/8 in. (9.5 mm) plywood or particleboard, 22 gauge sheet metal, or equivalent, from face of rack to face of rack, spaced at a maximum 16.5 ft (5.0 m) interval.
The vertical barrier shall extend from a maximum of 4 in. (102 mm) above the floor to the maximum storage height.
The plan area of storage between vertical barriers and aisles shall not exceed 124 ft2 (11.5 m2).
The vertical barrier shall extend across the longitudinal flue.
Commodity shall be permitted to extend a nominal 4 in. (100 mm) beyond the vertical barrier at the aisle.
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