The following words and terms shall, for the purposes of this chapter and as used elsewhere in this code, have the meanings shown herein.
In roofing, crushed stone, crushed slag or water-worn gravel used for surfacing for .roof coverings.
In roofing, .ballast comes in the form of large stones or paver systems or light-weight interlocking paver systems and is used to provide uplift resistance for roofing systems that are not adhered or mechanically attached to the roof deck.
A roofing product consisting of electricity generating photovoltaic component integrated into a .roof covering.
Two or more layers of felt cemented together and surfaced with a cap sheet, mineral .aggregate, smooth coating or similar surfacing material.
A layer of felt or nonbituminous saturated felt not less than 18 inches (457 mm) wide, shingled between each course of a wood-shake .roof covering.
A partially enclosed .rooftop structure used to aesthetically conceal heating, ventilating and air conditioning (HVAC) electrical or mechanical equipment from view.
An interlocking metal sheet having a minimum installed weather exposure of 3 square feet (0.279 m2) per sheet. .
An interlocking metal sheet having an installed weather exposure less than 3 square feet (0.279 m2) per sheet. .
One or more layers of polymer-modified asphalt sheets. The sheet materials shall be fully adhered or mechanically attached to the substrate or held in place with an .approved ballast layer.
An enclosed, unoccupied structure above the roof of a building, other than a tank, tower, spire, dome cupola or bulkhead. .
A complete, environmentally protected unit consisting of solar .cells, optics and other components, exclusive of tracker, designed to generate DC power when exposed to sunlight.
A collection of modules mechanically fastened together, wired and designed to provide a field-installable unit. .
The drainage condition in which consideration has been made for all loading deflections of the .roof deck, and additional slope has been provided to ensure drainage of the roof within 48 hours of precipitation.
A material having a low-emittance surface of 0.1 or less installed in building assemblies. .
A system designed to provide weather protection and resistance to design .loads. The system consists of a roof covering and roof deck or a single component serving as both the roof covering and the roof deck. A roof assembly includes the roof deck, vapor retarder, substrate or thermal barrier, insulation and roof covering.
The covering applied to the .roof deck for weather resistance, fire classification or appearance.
See “ .Roof assembly.”
The flat or sloped surface not including its supporting members or vertical supports. .
Reconstruction or renewal of any part of an .existing roof for the purposes of its maintenance.
A separation or division of a roof area by .existing joints, parapet walls, flashing (excluding valleys), difference of elevation (excluding hips and ridges), roof type or legal description; not including the roof area required for a proper tie-off with an existing system.
The natural or mechanical process of supplying conditioned or unconditioned air to, or removing such air from, .attics, cathedral ceilings or other enclosed spaces over which a roof assembly is installed.
An enclosed structure on or above the roof of any part of a building. .
An opening in a wall or parapet that allows water to drain from a roof. .
An assembly of interacting components designed to waterproof and normally insulate a building’s top surface that includes, by design, vegetation and related landscape elements. .
Flashing shall be used to seal roofing systems, where the system is interrupted or terminated and shall be installed in such a manner so as to prevent moisture entering the wall and roof through joints in copings, through moisture-permeable materials and at intersections with parapet walls and other penetrations through the roof plane.
METAL FLASHING MATERIAL
(LBS PER SQ FT)
|Copper||1 (16 oz)|
|0.0179||26 (zinc |
|Aluminum Zinc |
|0.0179||26 (AZ50 |
|Lead||2.5 (40 oz)|
|Painted Terne||1.25 (20 oz)|
Flashing shall be installed at wall and roof intersections, at gutters, wherever there is a change in roof slope or direction and around roof openings. Where flashing is of metal, the metal shall be corrosion resistant with a thickness of not less than provided in Table 1503.2 or in compliance with RAS 111.
Exception: This requirement does not apply to hip and ridge junctions.
A cricket or saddle shall be installed on the ridge side of any chimney or penetration greater than 30 inches (762 mm) wide as measured perpendicular to the slope. Cricket or saddle coverings shall be sheet metal or of the same material as the roof covering.
Exceptions: Metal roofs constructed of cold-formed steel, where the roof deck acts as the roof covering and provides both weather protection and support for structural loads, shall be permitted to be designed and tested in accordance with the applicable referenced structural design standard in Section 2210.1.
Aggregate shall be permitted as roof surfacing when installed on slopes of 3:12 or less, not less than 400 pound (182 kg) of roofing gravel or 300 pounds (145 kg) of slag per square shall be applied. A minimum of 50 percent of the total aggregate shall be embedded in the flood coat of bitumen or installed in accordance with its product approval. Aggregate shall be dry and free from dirt and shall be in compliance with the sizing requirements set forth in ASTM D1863. A building official may request a test to confirm compliance with these requirements.
Table1504.8 Maximum Allowable Mean Roof Height Permitted for Buildings with Aggregate on the Roof in Areas Outside A Hurricane-Prone Region.
A margin of safety of 2:1 shall be applied to all wind-uplift resistance-test results except when a margin of safety is specified in the test standard.
Exception: Asphalt shingles testing resulting in a miles per hour rating as required in Section 1507.2.7.
Roof assemblies shall be divided into the classes defined below. Class A, B and C roof assemblies and roof coverings required to be listed by this section shall be tested in accordance with ASTM E108 or UL 790. In addition, fire-retardant-treated wood roof coverings shall be tested in accordance with ASTM D2898. The minimum roof coverings installed on buildings shall comply with Table 1505.1 based on the type of construction of the building.
TABLE 1505.1a, b
MINIMUM ROOF COVERING CLASSIFICATION FOR TYPES OF CONSTRUCTION
For SI: 1 foot = 304.8 mm, 1 square foot = 0.0929 m2.
- Unless otherwise required in accordance with the International Wildland-Urban Interface Code or due to the location of the building within a fire district in accordance with Appendix D.
- Nonclassified roof coverings shall be permitted on buildings of Group R-3 and Group U occupancies, where there is a minimum fire-separation distance of 6 feet measured from the leading edge of the roof.
- Buildings that are not more than two stories above grade plane and having not more than 6,000 square feet of projected roof area and where there is a minimum 10-foot fire-separation distance from the leading edge of the roof to a lot line on all sides of the building, except for street fronts or public ways, shall be permitted to have roofs of No. 1 cedar or redwood shakes and No. 1 shingles constructed in accordance with Section 1505.7.
Class A roof assemblies are those that are effective against severe fire test exposure. Class A roof assemblies and roof coverings shall be listed and identified as Class A by an approved testing agency. Class A roof assemblies shall be permitted for use in buildings or structures of all types of construction.
- Class A roof assemblies include those with coverings of brick, masonry or an exposed concrete roof deck.
- Class A roof assemblies also include ferrous or copper shingles or sheets, metal sheets and shingles, clay or concrete roof tile or slate installed on noncombustible decks or ferrous, copper or metal sheets installed without a roof deck on noncombustible framing.
- Class A roof assemblies include minimum 16 ounce per square foot (0.0416 kg/m2) copper sheets installed over combustible decks.
Wood screws conform to ANSI/ASME B18.6.1. Screws shall be corrosion resistant by coating, galvanization, stainless steel, nonferrous metal or other suitable corrosion-resistant material. The corrosion resistance shall be demonstrated through one of the following methods:
Unless otherwise noted, underlayment for asphalt shingles, metal roof panels, metal roof shingles, mineral surfaced roll roofing, slate shingles, wood shingles, and wood shakes shall conform to the applicable standards listed in this chapter. Underlayment materials required to comply with ASTM D226, D1970, D4869 and D6757 shall bear a label indicating compliance to the standard designation and, if applicable, type classification indicated in Table 1507.1.1. Underlayment shall be applied and attached in accordance with Table 1507.1.1.
Exception: A reinforced synthetic underlayment that is approved as an alternative to underlayment complying with ASTM D226 Type II and having a minimum tear strength per ASTM D1970 or ASTM D4533 of 20 pounds (9.1 kg) shall be permitted. This underlayment shall be installed and attached in accordance with the underlayment attachment methods of Table 1507.1.1 for the applicable roof covering and slope, except metal cap nails shall be required where the ultimate design wind speed, Vult, equals or exceeds 150 mph.
|Roof Covering Section||Roof Slope 2:12 and Less Than 4:12||Underlayment |
|Roof Slope 4:12 and Greater||Underlayment |
|Asphalt shingles||ASTM D226 Type I or II ASTM D6757||1||ASTM D226 Type II ASTM D6757||2|
|ASTM D1970||3||ASTM D1970||3|
|Concrete and Clay Tile||See Section 1507.3.3|
|Metal roof panels||ASTM D226 Type I or II ASTM D6757||1||ASTM D226 Type II ASTM D6757||2|
|ASTM D1970||3||ASTM D1970||3|
|Metal roof shingles |
|ASTM D226 Type I or II ASTM D6757||1||ASTM D226 Type II ASTM D6757||2|
|ASTM D1970||3||ASTM D1970||3|
|Mineral-surfaced roll |
|ASTM D226 Type I or II ASTM D6757||1||ASTM D226 Type II ASTM D6757||2|
|ASTM D1970||3||ASTM D1970||3|
|Slate shingles||ASTM D226 Type I or II ASTM D6757||1||ASTM D226 Type II ASTM D6757||2|
|ASTM D1970||3||ASTM D1970||3|
|Wood shingles||ASTM D226 Type I or II||1||ASTM D226 Type II||2|
|Wood shakes||Limited to roof slopes |
4:12 and Greater
|ASTM D226 Type II||2|
|Photovoltaic Shingles||ASTM D226 Type I or II ASTM D6757||1||ASTM D226 Type II ASTM D6757||2|
|ASTM D1970||3||ASTM D1970||3|
- Roof slopes from two units vertical in 12 units horizontal (17-percent slope), and less than four units vertical in 12 units horizontal (33-percent slope). Apply a 19-inch (483 mm) strip of underlayment felt parallel to and starting at the eaves, fastened sufficiently to hold in place. Starting at the eave, apply 36-inchwide (914 mm) sheets of underlayment, overlapping successive sheets 19 inches (483 mm), end laps shall be 6 inches and shall be offset by 6 feet. The underlayment shall be attached to a nailable deck with corrosion-resistant fasteners with one row centered in the field of the sheet with a maximum fastener spacing of 12 inches (305 mm) o.c., and one row at the end and side laps fastened 6 inches (152 mm) o.c. Underlayment shall be attached using metal or plastic cap nails with a nominal cap diameter of not less than 1 inch. Metal caps shall have a thickness of not less than 32-gage sheet metal. Power-driven metal caps shall have a minimum thickness of 0.010 inch. Minimum thickness of the outside edge of plastic caps shall be 0.035 inch. The cap nail shank shall be not less than 0.083 inch for ring shank cap nails and 0.091 inch for smooth shank cap nails. Cap nail shank shall have a length sufficient to penetrate through the roof sheathing or not less than 3/4 inch into the roof sheathing.
- Roof slopes of four units vertical in 12 units horizontal (33-percent slope) or greater. Underlayment shall be applied shingle fashion, parallel to and starting from the eave and lapped 4 inches (51 mm), end laps shall be 6 inches and shall be offset by 6 feet. The underlayment shall be attached to a nailable deck with two staggered rows in the field of the sheet with a maximum fastener spacing of 12 inches (305 mm) o.c., and one row at the end and side laps fastened 6 inches (152 mm) o.c. Underlayment shall be attached using metal or plastic cap nails with a nominal cap diameter of not less than 1 inch. Metal caps shall have a thickness of not less than 32-gage sheet metal. Power-driven metal caps shall have a minimum thickness of 0.010 inch. Minimum thickness of the outside edge of plastic caps shall be 0.035 inch. The cap nail shank shall be not less than 0.083 inch for ring shank cap nails and 0.091 inch for smooth shank cap nails. Cap nail shank shall have a length sufficient to penetrate through the roof sheathing or not less than 3/4 inch into the roof sheathing.
Asphalt shingles shall be classified in accordance with ASTM D3161, ASTM D7158 or TAS 107. Shingles classified as ASTM D3161 Class D or ASTM D7158 Class G are acceptable for use where Vasd is equal to or less than 100 mph. Shingles classified as ASTM D3161 Class F, ASTM D7158 Class H or TAS 107 are acceptable for use for all wind speeds. Asphalt shingle wrappers shall indicate compliance with one of the required classifications, as shown in Table 1507.2.7.1.
Base and counter flashing shall be installed as follows:
- In accordance with manufacturer’s installation instructions, or
- In compliance with RAS-111, or
- A continuous metal minimum 4 inches by 4 inches “L” flashing shall be set in approved flashing cement and set flush to the base of the wall and over the underlayment. Both horizontal and vertical metal flanges shall be fastened 6 inches (152 mm) on center with approved fasteners. All laps shall be a minimum of 4 inches (102 mm) fully sealed in approved flashing cement. Flashing shall start at the lower portion of roof to insure water-shedding capabilities of all metal laps. The entire edge of the horizontal flange shall be sealed covering all nail penetrations with approved flashing cement and membrane. Shingles will overlap the horizontal flange and shall be set in approved flashing cement.
Base flashing shall be of either corrosion-resistant metal with a minimum thickness provided in Table 1503.2 or mineral surface roll roofing weighing a minimum of 77 pounds per 100 square feet (3.76 kg/ m2). Counter flashing shall be corrosion-resistant metal with a minimum thickness provided in Table 1503.2.
Valley linings shall be installed in accordance with the manufacturer’s instructions before applying shingles. Valley linings of the following types shall be permitted:
- For open valleys (valley lining exposed) lined with metal, the valley lining shall be at least 16 inches (406 mm) wide and of any of the corrosion-resistant metals in Table 1503.2.
- For open valleys, valley lining of two plies of mineral-surfaced roll roofing complying with ASTM D3909 or ASTM D6380 Class M-03 shall be permitted. The bottom layer shall be 18 inches (457 mm) and the top layer a minimum of 36 inches (914 mm) wide.
- For closed valleys (valleys covered with shingles), valley lining of one ply of smooth roll roofing complying with ASTM D6380 Class S-03, and at least 36 inches (914 mm) wide or types as described in Item 1 or 2 above shall be permitted. Self-adhering polymer modified bitumen underlayment complying with ASTM D1970 shall be permitted in lieu of the lining material.
Table1507.2.9.2 Valley Lining Material.
Clay and concrete roof tiles shall be fastened in accordance with Section 1609 or in accordance with FRSA/TRI Florida High Wind Concrete and Clay Roof Tile Installation Manual, Fifth Edition where the basic wind speed, Vasd, is determined in accordance with Section 1609.3.1.
Table 1507.3.7 Clay and Concrete Tile Attachment.
- The minimum slope for lapped, nonsoldered seam metal roof panels without applied lap sealant shall be three units vertical in 12 units horizontal (25-percent slope).
- The minimum slope for lapped, nonsoldered seam metal roof panels with applied lap sealant shall be one-half unit vertical in 12 units horizontal (4-percent slope). Lap sealants shall be applied in accordance with the approved manufacturer’s installation instructions.
- The minimum slope for standing-seam metal roof panel systems shall be one-quarter unit vertical in 12 units horizontal (2-percent slope).
Metal-sheet roof covering systems that incorporate supporting structural members shall be designed in accordance with Chapter 22. Metal-sheet roof coverings installed over structural decking shall comply with Table 1507.4.3(1). The materials used for metal-sheet roof coverings shall be naturally corrosion resistant or provided with corrosion resistance in accordance with the standards and minimum thicknesses shown in Table 1507.4.3(2).
METAL ROOF COVERINGS
|ROOF COVERING |
|STANDARD APPLICATION |
|Aluminum||ASTM B209, 0.024 inch minimum thickness |
for roll-formed panels and 0.019 inch minimumthickness for press-formed shingles.
alloy coated steel
|ASTM A792 AZ 50|
|Cold-rolled copper||ASTM B370 minimum 16 oz./sq. ft. and 12 |
oz./sq. ft. high yield copper for metal-sheetroof covering systems: 12 oz./sq. ft. for preformed
metal shingle systems.
|Copper||16 oz./sq. ft. for metal-sheet roof-covering |
systems; 12 oz./sq. ft. for preformed metalshingle systems.
|Galvanized steel||ASTM A653 G-90 zinc-coateda.|
|Hard lead||2 lbs./sq. ft.|
|Lead-coated copper||ASTM B101|
|Prepainted steel||ASTM A755|
|Soft lead||3 lbs./sq. ft.|
|Stainless steel||ASTM A240/A204M, 300 Series Alloys|
|Terne and terne-|
|Terne coating of 40 lbs. per double base box, |
field painted where applicable in accordancewith manufacturer’s installation instructions.
|Zinc||0.027 inch minimum thickness; 99.995% |
electrolytic high grade zinc with alloy additivesof copper (0.08% - 0.20%), titanium
(0.07% - 0.12%) and aluminum (0.015%).
For SI: 1 ounce per square foot = 0.305 kg/m2,
1 pound per square foot = 4.882 kg/m2,
1 inch = 25.4 mm, 1 pound = 0.454 kg.
- For Group U buildings, the minimum coating thickness for ASTM A653 galvanized steel roofing shall be G-60.
MINIMUM CORROSION RESISTANCE
|55% Aluminum-zinc alloy coated steel||ASTM A792 AZ 50|
|5% Aluminum alloy-coated steel||ASTM A875 GF60|
|Aluminum-coated steel||ASTM A463 T2 65|
|Galvanized steel||ASTM A653 G-90|
|Prepainted steel||ASTM A755a|
Metal roof panels shall be secured to the supports in accordance with the approved manufacturer’s fasteners. In the absence of manufacturer recommendations, the following fasteners shall be used:
- Galvanized fasteners shall be used for steel roofs.
- Copper, brass, bronze, copper alloy or 300 series stainless-steel fasteners shall be used for copper roofs.
- Stainless-steel fasteners are acceptable for all types of metal roofs.
- Aluminum fasteners are acceptable for aluminum roofs attached to aluminum supports.
All wood shingles shall be installed in accordance with this chapter and the manufacturer’s installation instructions, the Cedar Shake and Shingle Bureau New Roof Construction Manual or RAS 130. The product approval shall state the allowable uplift resistance for the attachment system. The installation of wood shingles shall be limited to roofs where the allowable uplift resistance is equal to or greater than the design uplift pressure for the roof in compliance with Section 1504.1.
Table 1507.8 Wood Shingle and Shake Installation.
Wood shakes shall comply with the requirements of Table 1507.9.6.
WOOD SHAKE MATERIAL REQUIREMENTS
|Wood shakes of naturally durable wood||1||CSSB|
|Taper sawn shakes of naturally durable |
|1 or 2||CSSB|
|Preservative-treated shakes and shingles of||1||CSSB|
|Fire-retardant-treated shakes and shingles||1||CSSB|
|Preservative-treated taper sawn shakes of |
Southern pine treated in accordance withAWPA U1 (Commodity Specification A,
Use Category 3B and Section 5.6)
|1 or 2||TFS|
CSSB = Cedar Shake and Shingle Bureau.
TFS = Forest Products Laboratory of the Texas Forest Services.
Built-up roof covering materials shall comply with the standards in Table 1507.10.2 or UL 55A.
BUILT-UP ROOFING MATERIAL STANDARDS
|Acrylic coatings used in roofing||ASTM D6083|
|Aggregate surfacing||ASTM D1863|
|Asphalt adhesive used in roofing||ASTM D3747|
|Asphalt cements used in roofing||ASTM D3019; D2822; |
|Asphalt-coated glass fiber base sheet||ASTM D4601|
|Asphalt coatings used in roofing||ASTM D1227; D2823; |
|Asphalt glass felt||ASTM D2178|
|Asphalt primer used in roofing||ASTM D41|
|Asphalt-saturated and asphalt-coated |
organic felt base sheet
|Asphalt-saturated organic felt (perforated)||ASTM D226|
|Asphalt used in roofing||ASTM D312|
|Coal-tar cements used in roofing||ASTM D4022; D5643|
|Coal-tar saturated organic felt||ASTM D227|
|Coal-tar pitch used in roofing||ASTM D450; Type I or II|
|Coal-tar primer used in roofing, |
dampproofing and waterproofing
|Glass mat, coal tar||ASTM D4990|
|Glass mat, venting type||ASTM D4897|
|Mineral-surfaced inorganic cap sheet||ASTM D3909|
|Thermoplastic fabrics used in roofing||ASTM D5665, D5726|
Foamed-in-place roof insulation shall be installed in accordance with the manufacturer’s instructions. A liquid-applied protective coating that complies with Table 1507.14.3 shall be applied no less than 2 hours nor more than 72 hours following the application of the foam.
The use of above-deck thermal insulation shall be permitted provided such insulation is covered with an approved roof covering and passes the tests of NFPA 276 or UL 1256 when tested as an assembly.
Above-deck thermal insulation board shall comply with the standards in Table 1508.2.
[BF] TABLE 1508.2
MATERIAL STANDARDS FOR ROOF INSULATION
|Cellular glass board||ASTM C552|
|Composite boards||ASTM C1289, Type III, IV, V or VI|
|Expanded polystyrene||ASTM C578|
|Extruded polystyrene||ASTM C578|
|Fiber-reinforced gypsum board||ASTM C1278|
|Glass-faced gypsum board||ASTM C1177|
|Lightweight insulating||ASTM C495, ASTM C513,|
|Mineral fiber insulation board||ASTM C726|
|Perlite board||ASTM C728|
|Polyisocyanurate board||ASTM C1289, Type I or II|
|Wood fiberboard||ASTM C208|
- On buildings of Type I construction, the exterior walls and roofs of penthouses with a fire separation distance greater than 5 feet (1524 mm) and less than 20 feet (6096 mm) shall be permitted to have not less than a 1-hour fire-resistance rating. The exterior walls and roofs of penthouses with a fire separation distance of 20 feet (6096 mm) or greater shall not be required to have a fire-resistance rating.
- On buildings of Type I construction two stories or less in height above grade plane or of Type II construction, the exterior walls and roofs of penthouses with a fire separation distance greater than 5 feet (1524 mm) and less than 20 feet (6096 mm) shall be permitted to have not less than a 1-hour fire-resistance rating or a lesser fire-resistance rating as required by Table 602 and be constructed of fire-retardant-treated wood. The exterior walls and roofs of penthouses with a fire separation distance of 20 feet (6096 mm) or greater shall be permitted to be constructed of fire-retardant-treated wood and shall not be required to have a fire-resistance rating. Interior framing and walls shall be permitted to be constructed of fire-retardant-treated wood.
- On buildings of Type III, IV or V construction, the exterior walls of penthouses with a fire separation distance greater than 5 feet (1524 mm) and less than 20 feet (6096 mm) shall be permitted to have not less than a 1-hour fire-resistance rating or a lesser fire-resistance rating as required by Table 602. On buildings of Type III, IV or VA construction, the exterior walls of penthouses with a fire separation distance of 20 feet (6096 mm) or greater shall be permitted to be of Type IV or noncombustible construction or fire-retardant-treated wood and shall not be required to have a fire-resistance rating.
Cooling towers located on the roof deck of a building and greater than 250 square feet (23.2 m2) in base area or greater than 15 feet (4572 mm) in height above the roof deck, as measured to the highest point on the cooling tower, where the roof is greater than 50 feet (15 240 mm) in height above grade plane shall be constructed of noncombustible materials. The base area of cooling towers shall not exceed one-third the area of the supporting roof deck.
Exception: Drip boards and the enclosing construction shall be permitted to be of wood not less than 1 inch (25 mm) nominal thickness, provided the wood is covered on the exterior of the tower with noncombustible material.
Regardless of the requirements in Section 1510.6, mechanical equipment screens that are located on the roof decks of buildings of Type I, II, III or IV construction shall be permitted to be constructed of combustible materials in accordance with any one of the following limitations:
- The fire separation distance shall be not less than 20 feet (6096 mm) and the height of the mechanical equipment screen above the roof deck shall not exceed 4 feet (1219 mm) as measured to the highest point on the mechanical equipment screen.
- The fire separation distance shall be not less than 20 feet (6096 mm) and the mechanical equipment screen shall be constructed of fire-retardant-treated wood complying with Section 2303.2 for exterior installation.
- Where exterior wall covering panels are used, the panels shall have a flame spread index of 25 or less when tested in the minimum and maximum thicknesses intended for use, with each face tested independently in accordance with ASTM E84 or UL 723. The panels shall be tested in the minimum and maximum thicknesses intended for use in accordance with, and shall comply with the acceptance criteria of, NFPA 285 and shall be installed as tested. Where the panels are tested as part of an exterior wall assembly in accordance with NFPA 285, the panels shall be installed on the face of the mechanical equipment screen supporting structure in the same manner as they were installed on the tested exterior wall assembly.
The height of mechanical equipment screens located on the roof decks of buildings of Type V construction, as measured from grade plane to the highest point on the mechanical equipment screen, shall be permitted to exceed the maximum building height allowed for the building by other provisions of this code where complying with any one of the following limitations, provided the fire separation distance is greater than 5 feet (1524 mm):
- Where the fire separation distance is not less than 20 feet (6096 mm), the height above grade plane of the mechanical equipment screen shall not exceed 4 feet (1219 mm) more than the maximum building height allowed;
- The mechanical equipment screen shall be constructed of noncombustible materials;
- The mechanical equipment screen shall be constructed of fire-retardant-treated wood complying with Section 2303.2 for exterior installation; or
- Where the fire separation distance is not less than 20 feet (6096 mm), the mechanical equipment screen shall be constructed of materials having a flame spread index of 25 or less when tested in the minimum and maximum thicknesses intended for use with each face tested independently in accordance with ASTM E84 or UL 723.
Aerial supports shall be constructed of noncombustible materials.
Exception: Aerial supports not greater than 12 feet (3658 mm) in height as measured from the roof deck to the highest point on the aerial supports shall be permitted to be constructed of combustible materials.
Roof mounted mechanical units shall be mounted on curbs raised a minimum of 8 inches (203 mm) above the roof surface, or where roofing materials extend beneath the unit, on raised equipment supports providing a minimum clearance height in accordance with Table 1510.10.
Exception: In buildings where the existing rooftop equipment, in the opinion of the building official, provides sufficient clearance to repair, recover, replace and/or maintain the roofing system or any of its components, such existing equipment need not comply with Table 1510.10.
CLEARANCE BELOW RAISED ROOF
MOUNTED MECHANICAL UNITS
|WIDTH OF MECHANICAL UNIT |
|MINIMUM CLEARANCE ABOVE |
|24 < 36||18|
|36 < 48||24|
|48 < 60||30|
For SI: 1 inch = 25.4mm.
Exception: Reroofing shall not be required to meet the minimum design slope requirement of one-quarter unit vertical in 12 units horizontal (2-percent slope) in Section 1507 for roofs that provide positive roof drainage.
- Where the existing roof or roof covering is water soaked or has deteriorated to the point that the existing roof or roof covering is not adequate as a base for additional roofing.
- Where the existing roof covering is wood shake, slate, clay, cement or asbestos-cement tile.
- Where the existing roof has two or more applications of any type of roof covering.
- When blisters exist in any roofing, unless blisters are cut or scraped open and remaining materials secured down before applying additional roofing.
- Complete and separate roofing systems, such as standing-seam metal roof systems, that are designed to transmit the roof loads directly to the building’s structural system and that do not rely on existing roofs and roof coverings for support, shall not require the removal of existing roof coverings.
- The application of a new protective coating over an existing spray polyurethane foam roofing system shall be permitted without tear-off of existing roof coverings.
- Where the existing roof assembly includes an ice barrier membrane that is adhered to the roof deck, the existing ice barrier membrane shall be permitted to remain in place and covered with an additional layer of ice barrier membrane in accordance with Section 1507.
For definitions outside Sections 1512 through 1525 and accompanied RAS and TAS, see Chapter 2. For the purposes of Sections 1512 through 1525, accompanying RAS, TAS and roofing products approval, roofing terms shall be defined in compliance with ASTM D1079, unless otherwise defined below. The definitions listed below shall take preference. Other terms used herein shall be defined as set forth in Chapter 2 of this code.
A .roofing system consisting of a prepared roof covering over an approved underlayment on a sloped roof. The components within the prepared roof covering are discontinuously laid and small, with unsealed side and head laps. Air permeable roofing systems shall be applied over sheathed decks with either mechanical attachment or a mortar/adhesive bond. Any roofing system with sealed side or head laps shall not be defined as an air permeable roofing system. The authority having jurisdiction may require testing in compliance with TAS 116, to determine whether a roofing system is air permeable.
A roofing felt mechanically attached to a nailable deck with approved fasteners to which insulation is then installed in a .solid mopping of asphalt. The roofing membrane is then installed to the insulation in the usual manner.
ASTM International). A scientific and technical organization that is responsible for the development of standards on characteristics and performance of materials, products, systems, as adopted for the high-velocity hurricane (zone.
The gross area of the smallest plane area of the ventilating device reduced by the percentage of physical obstruction to the plane area. (NFVA).
A roofing product consisting of electricity generating photovoltaic component integrated into a .roof covering.
“CLASS A” ROOFING ASSEMBLY. A roofing assembly that, in combination with the roof slope, has been classified by an approved testing agency, with a listing and follow-up service, as “Class A” in compliance with ASTM E108 or UL 790.
“CLASS B” ROOFING ASSEMBLY. A roofing assembly that, in combination with the roof slope, has been classified by an approved testing agency, with a listing and follow-up service, as “Class B” in compliance with ASTM E108 or UL 790.
“CLASS C” ROOFING ASSEMBLY. A roofing assembly that, in combination with the roof slope, has been classified by an approved testing agency, with a listing and follow-up service, as “Class C” in compliance with ASTM E108 or UL 790.
Any component that passes FM Global Test Standard 4470’s Appendix, as modified, and set forth in TAS .114.
Vertical wood strips installed on sloped roofs over which horizontal battens are secured. The primary .roof covering is attached or secured to these horizontal battens.
A .roofing system with unsealed overlapping components, where the combined roofing system has openings at the point of overlap, applied to a sloped surface with a pitch of 2:12, or greater. Discontinuous roofing systems include asphalt shingles; concrete, clay or metal tile; wood shingles or shakes; and cement fiber roofing systems.
The process of applying the first layer of felt in a .roofing system.
A research and testing organization that is responsible for examination and testing of construction and other products on behalf of member insurance companies. .
A static pullout test of mechanical fasteners, which are used to anchor any .roofing component, to determine the force required to withdraw a fastener from the substrate. Testing shall be in compliance with the test procedure detailed in TAS 105.
LAP. See NRCA Manual, 4th edition.
A force or pressure which is representative of data from withdrawal resistance testing; static uplift testing; and/ or wind uplift testing after the data has been statistically analyzed to a 95-percent level of precision. .
An interlocking metal sheet having an installed weather exposure equal or greater than 3 square feet (0.3 m2) per sheet. .
An interlocking metal sheet having an installed weather exposure less than 3 square feet (0.3 m2) per sheet. .
A quantity that represents the effect of a force applied at a particular point in relation to a specific point or axis. .
RAS. Roofing Application Standards.
A type of roofing product as described in .Section 1517.6 of this code.
ROOFING COATINGS, ADHESIVES AND MASTICS. Any and all liquid materials applied to the roofing membrane layer to enhance ultraviolet light resistance; increase resistance to fire; increase reflectivity of the roofing assembly; or, in some way, enhance the performance of the roofing assembly. Roofing coatings, adhesives or mastics shall not contain asbestos materials.
A roofing product that is incorporated into various .roofing assemblies.
.Solid or spaced sheathing to which the roofing or waterproofing system is applied.
The work of extending the longevity of a .roofing system through preventative care, such as refilling pitch pans, applying coatings, regraveling, resurfacing and recaulking.
A separation or division of a roof area by .existing expansion joints, parapet walls, flashing (excluding valleys), difference of elevation (excluding hips and ridges), roof type or legal description; not including the roof area required for a proper tie-off with an existing system.
A system of interacting .roofing components, generally consisting of membrane or primary roof covering and insulation (not including the roof deck) designed to weatherproof, and sometimes to improve, the building’s thermal resistance.
Those tiles having a riseto-width ratio greater than 0.20. .
Those tiles having a rise-towidth ratio less or equal than 0.20; except those tiles meeting the flat profile definition. .
Those tiles with less than 1/2-inch (12.7 mm) rise. .
TAS. Testing Application Standard.
One or more water-shedding layers applied to a sloped roof prior to the application of a .prepared roof covering. The primary purpose of an underlayment is defined as a water shedding layer to function in combination with a prepared roof covering.
Tapered or straight pieces of red cedar, or other wood types, of widths ranging from 3 inches to 14 inches (76 mm to 356 mm) ranging in lengths from 18 inches to 32 inches (457 mm to 813 mm) applied to a sloped roof, in conjunction with an approved .underlayment, forming a discontinuous prepared roof system.
Tapered pieces of red cedar, or other wood types, sawn on both faces, of widths ranging from 3 inches to 14 inches (76 mm to 356 mm) and lengths of 16 inches (406 mm), 18 inches (457 mm), and 24 inches (610 mm) applied to a sloped roof forming a discontinuous prepared roof system. .
Zero feet to 20 feet (0 to 6.1 m) distance separation measured horizontally from the closest point of any building edge to the nearest point to an adjoining structure, and all buildings with occupation greater than 300 persons.