ICC Subscriptions
 
SECTION 1507 REQUIREMENTS FOR ROOF COVERINGS

1507.1 Scope.
Roof coverings shall be applied in accordance with the applicable provisions of this section and the manufacturer's installation instructions.

1507.2 Asphalt shingles.
The installation of asphalt shingles shall comply with the provisions of this section.

1507.2.1 Deck requirements. Asphalt shingles shall be fastened to solidly sheathed decks.
1507.2.2 Slope. Asphalt shingles shall only be used on roof slopes of two units vertical in 12 units horizontal (17-percent slope) or greater. For roof slopes from two units vertical in 12 units horizontal (17-percent slope) up to four units vertical in 12 units horizontal (33-percent slope), double underlayment application is required in accordance with Section 1507.2.8.
1507.2.3 Underlayment. Unless otherwise noted, required underlayment shall conform to ASTM D 226, Type I, ASTM D 4869, Type I, or ASTM D 6757.
1507.2.4 Self-adhering polymer modified bitumen sheet. Self-adhering polymer modified bitumen sheet shall comply with ASTM D 1970.
1507.2.5 Asphalt shingles. Asphalt shingles shall comply with ASTM D 225 or ASTM D 3462.
1507.2.6 Fasteners. Fasteners for asphalt shingles shall be galvanized, stainless steel, aluminum or copper roofing nails, minimum 12 gage [0.105 inch (2.67 mm)] shank with a minimum 3/8 inch-diameter (9.5 mm) head, of a length to penetrate through the roofing materials and a minimum of 3/4 inch (19.1 mm) into the roof sheathing. Where the roof sheathing is less than 3/4 inch (19.1 mm) thick, the nails shall penetrate through the sheathing. Fasteners shall comply with ASTM F 1667.
1507.2.7 Attachment. Asphalt shingles shall have the minimum number of fasteners required by the manufacturer, but not less than four fasteners per strip shingle or two fasteners per individual shingle. Where the roof slope exceeds 21 units vertical in 12 units horizontal (21:12), shingles shall be installed as required by the manufacturer.
1507.2.7.1 Wind resistance. Asphalt shingles shall be tested in accordance with ASTM D 7158. Asphalt shingles shall meet the classification requirements of Table 1507.2.7.1(1) for the appropriate maximum basic wind speed. Asphalt shingle packaging shall bear a label to indicate compliance with ASTM D 7158 and the required classification in Table 1507.2.7.1(1).

Exception:
Asphalt shingles not included in the scope of ASTM D 7158 shall be tested and labeled to indicate compliance with ASTM D 3161 and the required classification in Table 1507.2.7.1(2).

TABLE 1507.2.7.1(1) CLASSIFICATION OF ASPHALT ROOF SHINGLES PER ASTM D 7158a


MAXIMUM BASIC WIND SPEED (mph) FROM FIGURE 1609
CLASSIFICATION
REQUIREMENT
85
D, G or H
90
D, G or H
100
G or H
110
G or H
120
G or H
130
H
140
H
150
H


For SI: 1 foot = 304.8 mm, 1 mile per hour = 0.447 m/s.


a. The standard calculations contained in ASTM D 7158 assume exposure category B or C and building height of 60 feet (18 288 mm) or less. Additional calculations are required for conditions outside of these assumptions.



TABLE 1507.2.7.1(2) CLASSIFICATION OF ASPHALT SHINGLES PER ASTM D 3161


MAXIMUM BASIC WIND SPEED (mph) FROM FIGURE 1609

CLASSIFICATION
 REQUIREMENT

85
A, D or F
90
A, D or F
100
A, D or F
110
F
120
F
130
F
140
F
150
F


For SI: 1 mile per hour = 0.447 m/s.
1507.2.8 Underlayment application. For roof slopes from two units vertical in 12 units horizontal (17-percent slope) and up to four units vertical in 12 units horizontal (33-percent slope), underlayment shall be two layers applied in the following manner. Apply a minimum 19-inch-wide (483 mm) strip of underlayment felt parallel with and starting at the eaves, fastened sufficiently to hold in place. Starting at the eave, apply 36-inch-wide (914 mm) sheets of underlayment overlapping successive sheets 19 inches (483 mm), by fastened sufficiently to hold in place. Distortions in the underlayment shall not interfere with the ability of the shingles to seal. For roof slopes of four units vertical in 12 units horizontal (33-percent slope) or greater, underlayment shall be one layer applied in the following manner. Underlayment shall be applied shingle fashion, parallel to and starting from the eave and lapped 2 inches (51 mm), fastened sufficiently to hold in place. Distortions in the underlayment shall not interfere with the ability of the shingles to seal.
1507.2.8.1 High wind attachment. Underlayment applied in areas subject to high winds [greater than 110 mph (49.2 m/s) in accordance with Figure 1609] shall be applied with corrosion-resistant fasteners in accordance with the manufacturer's instructions. Fasteners are to be applied along the overlap at a maximum spacing of 36 inches (914 mm) on center.
1507.2.8.2 Ice barrier. In areas where there has been a history of ice forming along the eaves causing a backup of water, an ice barrier that consists of at least two layers of underlayment cemented together or of a self-adhering polymer modified bitumen sheet shall be used in lieu of normal underlayment and extend from the lowest edges of all roof surfaces to a point at least 24 inches (610 mm) inside the exterior wall line of the building.

Exception:
Detached accessory structures that contain no conditioned floor area.
1507.2.9 Flashings. Flashing for asphalt shingles shall comply with this section. Flashing shall be applied in accordance with this section and the asphalt shingle manufacturer's printed instructions.
1507.2.9.1 Base and cap flashing. Base and cap flashing shall be installed in accordance with the manufacturer's instructions. Base flashing shall be of either corrosion-resistant metal of minimum nominal 0.019-inch (0.483 mm) thickness or mineral-surfaced roll roofing weighing a minimum of 77 pounds per 100 square feet (3.76 kg/m2). Cap flashing shall be corrosion-resistant metal of minimum nominal 0.019-inch (0.483 mm) thickness.
1507.2.9.2 Valleys. Valley linings shall be installed in accordance with the manufacturer's instructions before applying shingles. Valley linings of the following types shall be permitted:
1. For open valleys (valley lining exposed) lined with metal, the valley lining shall be at least 24 inches (610 mm) wide and of any of the corrosion-resistant metals in Table 1507.2.9.2.
2. For open valleys, valley lining of two plies of mineral-surfaced roll roofing complying with ASTM D 3909 or ASTM D 6380 shall be permitted. The bottom layer shall be 18 inches (457 mm) and the top layer a minimum of 36 inches (914 mm) wide.
3. For closed valleys (valleys covered with shingles), valley lining of one ply of smooth roll roofing complying with ASTM D 6380, 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 D 1970 shall be permitted in lieu of the lining material.

TABLE 1507.2.9.2 VALLEY LINING MATERIAL


MATERIAL
MINIMUM THICKNESS
GAGE
WEIGHT
Aluminum
0.024 in.
-
-
Cold-rolled copper
0.0216 in.
-
ASTM B 370, 16 oz. per square ft.
Copper
-
-
16 oz
Galvanized steel
0.0179 in.
26 (zinc-coated G90)
-
High-yield copper
0.0162 in.
-
ASTM B 370, 12 oz. per square ft.
Lead
-
-
2.5 pounds
Lead-coated copper
0.0216 in.
-
ASTM B 101, 16 oz. per square ft.
Lead-coated high-yield copper
0.0162 in.
-
ASTM B 101, 12 oz. per square ft.
Painted terne
-
-
20 pounds
Stainless steel
-
28
-
Zinc alloy
0.027 in.
-
-


For SI: 1 inch = 25.4 mm, 1 pound = 0.454 kg, 1 ounce = 28.35 g, 1 ounce per square foot = 305.15 g/m2.
1507.2.9.3 Drip edge. Provide drip edge at eaves and gables of shingle roofs. Overlap to be a minimum of 2 inches (51 mm). Eave drip edges shall extend 1/4 inch (6.4 mm) below sheathing and extend back on the roof a minimum of 2 inches (51 mm). Drip edge shall be mechanically fastened a maximum of 12 inches (305 mm) o.c.
1507.3 Clay and concrete tile. The installation of clay and concrete tile shall comply with the provisions of this section.

1507.3.1 Deck requirements. Concrete and clay tile shall be installed only over solid sheathing or spaced structural sheathing boards.
1507.3.2 Deck slope. Clay and concrete roof tile shall be installed on roof slopes of 21/2 units vertical in 12 units horizontal (21-percent slope) or greater. For roof slopes from 21/2 units vertical in 12 units horizontal (21-percent slope) to four units vertical in 12 units horizontal (33-percent slope), double underlayment application is required in accordance with Section 1507.3.3.
1507.3.3 Underlayment. Unless otherwise noted, required underlayment shall conform to: ASTM D 226, Type II; ASTM D 2626 or ASTM D 6380, Class M mineral-surfaced roll roofing.
1507.3.3.1 Low-slope roofs. For roof slopes from 21/2 units vertical in 12 units horizontal (21-percent slope), up to four units vertical in 12 units horizontal (33-percent slope), underlayment shall be a minimum of two layers applied as follows:
1. Starting at the eave, a 19-inch (483 mm) strip of underlayment shall be applied parallel with the eave and fastened sufficiently in place.
2. Starting at the eave, 36-inch-wide (914 mm) strips of underlayment felt shall be applied overlapping successive sheets 19 inches (483 mm) and fastened sufficiently in place.
1507.3.3.2 High-slope roofs. For roof slopes of four units vertical in 12 units horizontal (33-percent slope) or greater, underlayment shall be a minimum of one layer of underlayment felt applied shingle fashion, parallel to, and starting from the eaves and lapped 2 inches (51 mm), fastened only as necessary to hold in place.
1507.3.4 Clay tile. Clay roof tile shall comply with ASTM C 1167.
1507.3.5 Concrete tile. Concrete roof tile shall comply with ASTM C 1492.
1507.3.6 Fasteners. Tile fasteners shall be corrosion resistant and not less than 11 gage, 5/16-inch (8.0 mm) head, and of sufficient length to penetrate the deck a minimum of 3/4 inch (19.1 mm) or through the thickness of the deck, whichever is less. Attaching wire for clay or concrete tile shall not be smaller than 0.083 inch (2.1 mm). Perimeter fastening areas include three tile courses but not less than 36 inches (914 mm) from either side of hips or ridges and edges of eaves and gable rakes.
1507.3.7 Attachment. Clay and concrete roof tiles shall be fastened in accordance with Table 1507.3.7.

TABLE 1507.3.7 CLAY AND CONCRETE TILE ATTACHMENTa,b,c


GENERAL-CLAY OR CONCRETE ROOF TILE
Maximum basic
wind speed
(mph)
Mean roof
height
(feet)
Roof slope up to < 3:12
Roof slope 3:12 and over
85
0-60
One fastener per tile. Flat tile without vertical laps, two fasteners per tile. Two fasteners per tile. Only one fastener on slopes of 7:12 and less for tiles with installed weight exceeding 7.5 lbs./sq. ft. having a width no greater than 16 inches.
100
0-40
100
> 40-60
The head of all tiles shall be nailed. The nose of all eave tiles shall be fastened with approved clips. All rake tiles shall be nailed with two nails. The nose of all ridge, hip and rake tiles shall be set in a bead of roofer's mastic.
110
0-60
The fastening system shall resist the wind forces in Section 1609.5.3.
120
0-60
The fastening system shall resist the wind forces in Section 1609.5.3.
130
0-60
The fastening system shall resist the wind forces in Section 1609.5.3.
All
> 60
The fastening system shall resist the wind forces in Section 1609.5.3.
INTERLOCKING CLAY OR CONCRETE ROOF TILE WITH PROJECTING ANCHOR LUGSd,e
(Installations on spaced/solid sheathing with battens or spaced sheathing)
Maximum basic
wind speed
(mph)
Mean roof
height
(feet)
Roof slope up to < 5:12
Roof slope 5:12 < 12:12
Roof slope 12:12 and over
85
0-60
Fasteners are not required. Tiles with installed weight less than 9 lbs./sq. ft. require a minimum of one fastener per tile. One fastener per tile every other row. All perimeter tiles require
one fastener. Tiles with installed weight less than 9 lbs./sq. ft. require a minimum of one
fastener per tile.
One fastener required for
every tile. Tiles with installed weight less than 9 lbs./sq. ft. require a minimum of one fastener per tile.
100
0-40
100
> 40-60
The head of all tiles shall be nailed. The nose of all eave tiles shall be fastened with approved clips. All rake tiles shall be nailed with two nails The nose of all ridge, hip and rake tiles shall be set in a bead of roofer's mastic.
110
0-60
The fastening system shall resist the wind forces in Section 1609.5.3.
120
0-60
The fastening system shall resist the wind forces in Section 1609.5.3.
130
0-60
The fastening system shall resist the wind forces in Section 1609.5.3.
All
> 60
The fastening system shall resist the wind forces in Section 1609.5.3.
INTERLOCKING CLAY OR CONCRETE ROOF TILE WITH PROJECTING ANCHOR LUGS
(Installations on solid sheathing without battens)
Maximum basic
wind speed
(mph)
Mean roof
height
(feet)
All roof slopes
85
0-60
One fastener per tile.
100
0-40
One fastener per tile.
100
> 40-60
The head of all tiles shall be nailed. The nose of all eave tiles shall be fastened with approved clips. All rake tiles shall be nailed with two nails The nose of all ridge, hip and rake tiles shall be set in a bead of roofer's mastic.
110
0-60
The fastening system shall resist the wind forces in Section 1609.5.3.
120
0-60
The fastening system shall resist the wind forces in Section 1609.5.3.
130
0-60
The fastening system shall resist the wind forces in Section 1609.5.3.
All
> 60
The fastening system shall resist the wind forces in Section 1609.5.3.


For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 mile per hour = 0.447 m/s, 1 pound per square foot = 4.882 kg/m2.


a. Minimum fastener size. Corrosion-resistant nails not less than No. 11 gage with 5/16-inch head. Fasteners shall be long enough to penetrate into the sheathing 3/4 inch or through the thickness of the sheathing, whichever is less. Attaching wire for clay and concrete tile shall not be smaller than 0.083 inch.


b. Snow areas. A minimum of two fasteners per tile are required or battens and one fastener.


c. Roof slopes greater than 24:12. The nose of all tiles shall be securely fastened.


d. Horizontal battens. Battens shall be not less than 1 inch by 2 inch nominal. Provisions shall be made for drainage by a minimum of 1/8-inch riser at each nail or by 4-foot-long battens with at least a 1/2-inch separation between battens. Horizontal battens are required for slopes over 7:12.


e. Perimeter fastening areas include three tile courses but not less than 36 inches from either side of hips or ridges and edges of eaves and gable rakes.

1507.3.8 Application. Tile shall be applied according to the manufacturer's installation instructions, based on the following:
1. Climatic conditions.
2. Roof slope.
3. Underlayment system.
4. Type of tile being installed.
1507.3.9 Flashing. At the juncture of the roof vertical surfaces, flashing and counterflashing shall be provided in accordance with the manufacturer's installation instructions, and where of metal, shall not be less than 0.019-inch (0.48 mm) (No. 26 galvanized sheet gage) corrosion-resistant metal. The valley flashing shall extend at least 11 inches (279 mm) from the centerline each way and have a splash diverter rib not less than 1 inch (25 mm) high at the flow line formed as part of the flashing. Sections of flashing shall have an end lap of not less than 4 inches (102 mm). For roof slopes of three units vertical in 12 units horizontal (25-percent slope) and over, the valley flashing shall have a 36-inch-wide (914 mm) underlayment of either one layer of Type I underlayment running the full length of the valley, or a self-adhering polymer-modified bitumen sheet complying with ASTM D 1970, in addition to other required underlayment. In areas where the average daily temperature in January is 25°F (-4°C) or less or where there is a possibility of ice forming along the eaves causing a backup of water, the metal valley flashing underlayment shall be solid cemented to the roofing underlayment for slopes under seven units vertical in 12 units horizontal (58-percent slope) or self-adhering polymer-modified bitumen sheet shall be installed.
1507.4 Metal roof panels. The installation of metal roof panels shall comply with the provisions of this section.

1507.4.1 Deck requirements. Metal roof panel roof coverings shall be applied to a solid or closely fitted deck, except where the roof covering is specifically designed to be applied to spaced supports.
1507.4.2 Deck slope. Minimum slopes for metal roof panels shall comply with the following:
1. The minimum slope for lapped, nonsoldered seam metal roofs without applied lap sealant shall be three units vertical in 12 units horizontal (25-percent slope).
2. The minimum slope for lapped, nonsoldered seam metal roofs 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.
3. The minimum slope for standing seam of roof systems shall be one-quarter unit vertical in 12 units horizontal (2-percent slope).
1507.4.3 Material standards. 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).

TABLE 1507.4.3(1) METAL ROOF COVERINGS


ROOF COVERING TYPE STANDARD APPLICATION
RATE/THICKNESS
Aluminum ASTM B 209, 0.024 inch minimum thickness for roll-formed panels and 0.019 inch minimum thickness for press-formed shingles.
Aluminum-zinc alloy coated steel ASTM A 792 AZ 50
Cold-rolled copper ASTM B 370 minimum 16 oz./sq. ft. and
12 oz./sq. ft. high yield copper for
metal-sheet roof 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 metal shingle systems.
Galvanized steel ASTM A 653 G-90 zinc-coateda.
Hard lead 2 lbs./sq. ft.
Lead-coated copper ASTM B 101
Prepainted steel ASTM A 755
Soft lead 3 lbs./sq. ft.
Stainless steel ASTM A 240, 300 Series Alloys
Steel ASTM A 924
Terne and
terne-coated stainless
Terne coating of 40 lbs. per double base box, field painted where applicable in accordance with manufacturer's
installation instructions.
Zinc 0.027 inch minimum thickness; 99.995% electrolytic high grade zinc with alloy additives of 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.

a. For Group U buildings, the minimum coating thickness for ASTM A 653 galvanized steel roofing shall be G-60.


TABLE 1507.4.3(2) MINIMUM CORROSION RESISTANCE


55% Aluminum-zinc alloy coated steel ASTM A 792 AZ 50
5% Aluminum alloy-coated steel ASTM A 875 GF60
Aluminum-coated steel ASTM A 463 T2 65
Galvanized steel ASTM A 653 G-90
Prepainted steel ASTM A 755a


a. Paint systems in accordance with ASTM A 755 shall be applied over steel products with corrosion resistant coatings complying with ASTM A 463, ASTM A 653, ASTM A 792 or ASTM A 875.
1507.4.4 Attachment. 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:
1. Galvanized fasteners shall be used for steel roofs.
2. Copper, brass, bronze, copper alloy or 300 series stainless-steel fasteners shall be used for copper roofs.
3. Stainless-steel fasteners are acceptable for all types of metal roofs.
1507.5 Metal roof shingles. The installation of metal roof shingles shall comply with the provisions of this section.

1507.5.1 Deck requirements. Metal roof shingles shall be applied to a solid or closely fitted deck, except where the roof covering is specifically designed to be applied to spaced sheathing.
1507.5.2 Deck slope. Metal roof shingles shall not be installed on roof slopes below three units vertical in 12 units horizontal (25-percent slope).
1507.5.3 Underlayment. Underlayment shall comply with ASTM D 226, Type I or ASTM D 4869.
1507.5.4 Ice barrier. In areas where there has been a history of ice forming along the eaves causing a backup of water, an ice barrier that consists of at least two layers of underlayment cemented together or of a self-adhering polymer-modified bitumen sheet shall be used in lieu of normal underlayment and extend from the lowest edges of all roof surfaces to a point at least 24 inches (610 mm) inside the exterior wall line of the building.

Exception:
Detached accessory structures that contain no conditioned floor area.
1507.5.5 Material standards. Metal roof shingle roof coverings shall comply with Table 1507.4.3(1). The materials used for metal-roof shingle roof coverings shall be naturally corrosion resistant or provided with corrosion resistance in accordance with the standards and minimum thicknesses specified in the standards listed in Table 1507.4.3(2).
1507.5.6 Attachment. Metal roof shingles shall be secured to the roof in accordance with the approved manufacturer's installation instructions.
1507.5.7 Flashing. Roof valley flashing shall be of corrosion-resistant metal of the same material as the roof covering or shall comply with the standards in Table 1507.4.3(1). The valley flashing shall extend at least 8 inches (203 mm) from the centerline each way and shall have a splash diverter rib not less than 3/4 inch (19.1 mm) high at the flow line formed as part of the flashing. Sections of flashing shall have an end lap of not less than 4 inches (102 mm). In areas where the average daily temperature in January is 25°F (-4°C) or less or where there is a possibility of ice forming along the eaves causing a backup of water, the metal valley flashing shall have a 36-inch-wide (914 mm) underlayment directly under it consisting of either one layer of underlayment running the full length of the valley or a self-adhering polymer-modified bitumen sheet complying with ASTM D 1970, in addition to underlayment required for metal roof shingles. The metal valley flashing underlayment shall be solidly cemented to the roofing underlayment for roof slopes under seven units vertical in 12 units horizontal (58-percent slope) or self-adhering polymer-modified bitumen sheet shall be installed.
1507.6 Mineral-surfaced roll roofing. The installation of mineral-surfaced roll roofing shall comply with this section.

1507.6.1 Deck requirements. Mineral-surfaced roll roofing shall be fastened to solidly sheathed roofs.
1507.6.2 Deck slope. Mineral-surfaced roll roofing shall not be applied on roof slopes below one unit vertical in 12 units horizontal (8-percent slope).
1507.6.3 Underlayment. Underlayment shall comply with ASTM D 226, Type I or ASTM D 4869.
1507.6.4 Ice barrier. In areas where there has been a history of ice forming along the eaves causing a backup of water, an ice barrier that consists of at least two layers of underlayment cemented together or of a self-adhering polymer-modified bitumen sheet shall be used in lieu of normal underlayment and extend from the lowest edges of all roof surfaces to a point at least 24 inches (610 mm) inside the exterior wall line of the building.

Exception:
Detached accessory structures that contain no conditioned floor area.
1507.6.5 Material standards. Mineral-surfaced roll roofing shall conform to ASTM D 3909 or ASTM D 6380.
1507.7 Slate shingles. The installation of slate shingles shall comply with the provisions of this section.

1507.7.1 Deck requirements. Slate shingles shall be fastened to solidly sheathed roofs.
1507.7.2 Deck slope. Slate shingles shall only be used on slopes of four units vertical in 12 units horizontal (4:12) or greater.
1507.7.3 Underlayment. Underlayment shall comply with ASTM D 226, Type I or ASTM D 4869.
1507.7.4 Ice barrier. In areas where the average daily temperature in January is 25°F (-4°C) or less or where there is a possibility of ice forming along the eaves causing a backup of water, an ice barrier that consists of at least two layers of underlayment cemented together or of a self-adhering polymer-modified bitumen sheet shall extend from the lowest edges of all roof surfaces to a point at least 24 inches (610 mm) inside the exterior wall line of the building.

Exception:
Detached accessory structures that contain no conditioned floor area.
1507.7.5 Material standards. Slate shingles shall comply with ASTM C 406.
1507.7.6 Application. Minimum headlap for slate shingles shall be in accordance with Table 1507.7.6. Slate shingles shall be secured to the roof with two fasteners per slate.

TABLE 1507.7.6 SLATE SHINGLE HEADLAP


SLOPE
HEADLAP
(inches)
4:12 < slope < 8:12
4
8:12 < slope < 20:12
3
Slope ≥ 20:12
2


For SI: 1 inch = 25.4 mm.
1507.7.7 Flashing. Flashing and counterflashing shall be made with sheet metal. Valley flashing shall be a minimum of 15 inches (381 mm) wide. Valley and flashing metal shall be a minimum uncoated thickness of 0.0179-inch (0.455 mm) zinc-coated G90. Chimneys, stucco or brick walls shall have a minimum of two plies of felt for a cap flashing consisting of a 4-inch-wide (102 mm) strip of felt set in plastic cement and extending 1 inch (25 mm) above the first felt and a top coating of plastic cement. The felt shall extend over the base flashing 2 inches (51 mm).
1507.8 Wood shingles. The installation of wood shingles shall comply with the provisions of this section and Table 1507.8.

TABLE 1507.8 WOOD SHINGLE AND SHAKE INSTALLATION



ROOF ITEM
WOOD SHINGLES
WOOD SHAKES
1. Roof slope Wood shingles shall be installed on slopes of three units vertical in 12 units horizontal (3:12) or greater. Wood shakes shall be installed on slopes of four units vertical in 12 units horizontal (4:12) or greater.
2. Deck requirement  
Temperate climate Shingles shall be applied to roofs with solid or spaced sheathing. Where spaced sheathing is used, sheathing boards shall not be less than 1″ ×4″nominal dimensions and shall be spaced on center equal to the weather exposure to coincide with the placement of fasteners. Shakes shall be applied to roofs with solid or spaced sheathing. Where spaced sheathing is used, sheathing boards shall not be less than 1″ ×4″nominal dimensions and shall be spaced on center equal to the weather exposure to coincide with the placement of fasteners. When 1″ ×4″spaced sheathing is installed at 10 inches, boards must be installed between the sheathing boards.
In areas where the average daily temperature in January is 25°F or less or where there is a possibility of ice forming along the eaves causing a backup of water. Solid sheathing required. Solid sheathing is required.
3. Interlayment No requirements. Interlayment shall comply with ASTM D 226, Type 1.
4. Underlayment
  Temperate climate Underlayment shall comply with
ASTM D 226, Type 1.
Underlayment shall comply with
ASTM D 226, Type 1.
  In areas where there is a possibility of ice forming along the eaves causing a backup of water. An ice barrier that consists of at least two layers of underlayment cemented together or of a self-adhering polymer-modified bitumen sheet shall extend from the eave's edge to a point at least 24 inches inside the exterior wall line of the building. An ice barrier that consists of at least two layers of underlayment cemented together or of a self-adhering polymer-modified bitumen sheet shall extend from the lowest edges of all roof surfaces to a point at least 24 inches inside the exterior wall line of the building.
5. Application
  Attachment Fasteners for wood shingles shall be hot- dipped galvanized or Type 304 (Type 316 for coastal areas) stainless steel with a minimum penetration of 0.75 inch into the sheathing. For sheathing less than 0.5 inch thick, the fasteners shall extend through the sheathing. Fasteners for wood shakes shall be hot-dipped galvanized or Type 304 (Type 316 for coastal areas) with a minimum penetration of 0.75 inch into the sheathing. For sheathing less than 0.5 inch thick, the fasteners shall extend through the sheathing.
  No. of fasteners Two per shingle. Two per shake.
  Exposure Weather exposures shall not exceed those set forth in Table 1507.8.7. Weather exposures shall not exceed those set forth in Table 1507.9.8.
  Method Shingles shall be laid with a side lap of not less than 1.5 inches between joints in courses, and no two joints in any three adjacent courses shall be in direct alignment. Spacing between shingles shall be 0.25 to 0.375 inch. Shakes shall be laid with a side lap of not less than 1.5 inches between joints in adjacent courses. Spacing between shakes shall not be less than 0.375 inch or more than 0.625 inch for shakes and taper sawn shakes of naturally durable wood and shall be 0.25 to 0.375 inch for preservative-treated taper sawn shakes.
  Flashing In accordance with Section 1507.8.8. In accordance with Section 1507.9.9.


For SI: 1 inch = 25.4 mm, °C = [(°F) - 32]/1.8.


1507.8.1 Deck requirements. Wood shingles shall be installed on solid or spaced sheathing. Where spaced sheathing is used, sheathing boards shall not be less than 1-inch by 4-inch (25 mm by 102 mm) nominal dimensions and shall be spaced on centers equal to the weather exposure to coincide with the placement of fasteners.
1507.8.1.1 Solid sheathing required. Solid sheathing is required in areas where the average daily temperature in January is 25°F (-4°C) or less or where there is a possibility of ice forming along the eaves causing a backup of water.
1507.8.2 Deck slope. Wood shingles shall be installed on slopes of three units vertical in 12 units horizontal (25-percent slope) or greater.
1507.8.3 Underlayment. Underlayment shall comply with ASTM D 226, Type I or ASTM D 4869.
1507.8.4 Ice barrier. In areas where there has been a history of ice forming along the eaves causing a backup of water, an ice barrier that consists of at least two layers of underlayment cemented together or of a self-adhering polymer-modified bitumen sheet shall be used in lieu of normal underlayment and extend from the lowest edges of all roof surfaces to a point at least 24 inches (610 mm) inside the exterior wall line of the building.

Exception:
Detached accessory structures that contain no conditioned floor area.
1507.8.5 Material standards. Wood shingles shall be of naturally durable wood and comply with the requirements of Table 1507.8.5.

TABLE 1507.8.5 WOOD SHINGLE MATERIAL REQUIREMENTS
 



MATERIAL
APPLICABLE MINIMUM GRADES
GRADING RULES
Wood shingles of naturally durable wood
1, 2 or 3
CSSB


CSSB = Cedar Shake and Shingle Bureau
1507.8.6 Attachment. Fasteners for wood shingles shall be corrosion resistant with a minimum penetration of 3/4 inch (19.1 mm) into the sheathing. For sheathing less than 1/2 inch (12.7 mm) in thickness, the fasteners shall extend through the sheathing. Each shingle shall be attached with a minimum of two fasteners.
1507.8.7 Application. Wood shingles shall be laid with a side lap not less than 11/2 inches (38 mm) between joints in adjacent courses, and not be in direct alignment in alternate courses. Spacing between shingles shall be 1/4 to 3/8 inches (6.4 to 9.5 mm). Weather exposure for wood shingles shall not exceed that set in Table 1507.8.7.

TABLE 1507.8.7 WOOD SHINGLE WEATHER EXPOSURE AND ROOF SLOPE


ROOFING MATERIAL LENGTH
(inches)
GRADE EXPOSURE (inches)
3:12 pitch to < 4:12 4:12 pitch or steeper
Shingles of naturally durable wood
16
No. 1
No. 2
No. 3
3.75
3.5
3
5
4
3.5
18
No. 1
No. 2
No. 3
4.25
4
3.5
5.5
4.5
4
24
No. 1
No. 2
No. 3
5.75
5.5
5
7.5
6.5
5.5


For SI: 1 inch = 25.4 mm.
1507.8.8 Flashing. At the juncture of the roof and vertical surfaces, flashing and counterflashing shall be provided in accordance with the manufacturer's installation instructions, and where of metal, shall not be less than 0.019-inch (0.48 mm) (No. 26 galvanized sheet gage) corrosion-resistant metal. The valley flashing shall extend at least 11 inches (279 mm) from the centerline each way and have a splash diverter rib not less than 1 inch (25 mm) high at the flow line formed as part of the flashing. Sections of flashing shall have an end lap of not less than 4 inches (102 mm). For roof slopes of three units vertical in 12 units horizontal (25-percent slope) and over, the valley flashing shall have a 36-inch-wide (914 mm) underlayment of either one layer of Type I underlayment running the full length of the valley or a self-adhering polymer-modified bitumen sheet complying with ASTM D 1970, in addition to other required underlayment. In areas where the average daily temperature in January is 25°F (-4°C) or less or where there is a possibility of ice forming along the eaves causing a backup of water, the metal valley flashing underlayment shall be solidly cemented to the roofing underlayment for slopes under seven units vertical in 12 units horizontal (58-percent slope) or self-adhering polymer-modified bitumen sheet shall be installed.
1507.9 Wood shakes. The installation of wood shakes shall comply with the provisions of this section and Table 1507.8.

1507.9.1 Deck requirements. Wood shakes shall only be used on solid or spaced sheathing. Where spaced sheathing is used, sheathing boards shall not be less than 1-inch by 4-inch (25 mm by 102 mm) nominal dimensions and shall be spaced on centers equal to the weather exposure to coincide with the placement of fasteners. Where 1-inch by 4-inch (25 mm by 102 mm) spaced sheathing is installed at 10 inches (254 mm) o.c., additional 1-inch by 4-inch (25 mm by 102 mm) boards shall be installed between the sheathing boards.
1507.9.1.1 Solid sheathing required. Solid sheathing is required in areas where the average daily temperature in January is 25°F (-4°C) or less or where there is a possibility of ice forming along the eaves causing a backup of water.
1507.9.2 Deck slope. Wood shakes shall only be used on slopes of four units vertical in 12 units horizontal (33-percent slope) or greater.
1507.9.3 Underlayment. Underlayment shall comply with ASTM D 226, Type I or ASTM D 4869.
1507.9.4 Ice barrier. In areas where there has been a history of ice forming along the eaves causing a backup of water, an ice barrier that consists of at least two layers of underlayment cemented together or of a self-adhering polymer-modified bitumen sheet shall be used in lieu of normal underlayment and extend from the lowest edges of all roof surfaces to a point at least 24 inches (610 mm) inside the exterior wall line of the building.

Exception:
Detached accessory structures that contain no conditioned floor area.
1507.9.5 Interlayment. Interlayment shall comply with ASTM D 226, Type I.
1507.9.6 Material standards. Wood shakes shall comply with the requirements of Table 1507.9.6.

TABLE 1507.9.6 WOOD SHAKE MATERIAL REQUIREMENTS


MATERIAL
MINIMUM GRADES
APPLICABLE GRADING RULES
Wood shakes of naturally durable wood
1
CSSB
Taper sawn shakes of naturally durable wood
1 or 2
CSSB
Preservative-treated shakes and shingles of naturally durable wood
1
CSSB
Fire-retardant-treated shakes and shingles of naturally durable wood
1
CSSB
Preservative-treated taper sawn shakes of Southern pine treated in accordance with AWPA 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.
1507.9.7 Attachment. Fasteners for wood shakes shall be corrosion resistant with a minimum penetration of 3/4 inch (19.1 mm) into the sheathing. For sheathing less than 1/2 inch (12.7 mm) in thickness, the fasteners shall extend through the sheathing. Each shake shall be attached with a minimum of two fasteners.
1507.9.8 Application. Wood shakes shall be laid with a side lap not less than 11/2 inches (38 mm) between joints in adjacent courses. Spacing between shakes in the same course shall be 3/8 to 5/8 inches (9.5 to 15.9 mm) for shakes and taper sawn shakes of naturally durable wood and shall be 1/4 to 3/8 inch (6.4 to 9.5 mm) for preservative taper sawn shakes. Weather exposure for wood shakes shall not exceed those set in Table 1507.9.8.

TABLE 1507.9.8 WOOD SHAKE WEATHER EXPOSURE AND ROOF SLOPE


ROOFING MATERIAL
LENGTH
(inches)
GRADE
EXPOSURE (inches)
4:12 PITCH
OR STEEPER
Shakes of naturally
durable wood
18
24
No. 1
No. 1
7.5
10a
Preservative-treated taper sawn shakes of Southern yellow pine
18
24
No. 1
No. 1
7.5
10
18
24
No. 2
No. 2
5.5
7.5
Taper sawn shakes of naturally durable wood
18
24
No. 1
No. 1
7.5
10
18
24
No. 2
No. 2
5.5
7.5


For SI: 1 inch = 25.4 mm.

a. For 24-inch by 0.375-inch handsplit shakes, the maximum exposure is 7.5 inches.
1507.9.9 Flashing. At the juncture of the roof and vertical surfaces, flashing and counterflashing shall be provided in accordance with the manufacturer's installation instructions, and where of metal, shall not be less than 0.019-inch (0.48 mm) (No. 26 galvanized sheet gage) corrosion-resistant metal. The valley flashing shall extend at least 11 inches (279 mm) from the centerline each way and have a splash diverter rib not less than 1 inch (25 mm) high at the flow line formed as part of the flashing. Sections of flashing shall have an end lap of not less than 4 inches (102 mm). For roof slopes of three units vertical in 12 units horizontal (25-percent slope) and over, the valley flashing shall have a 36-inch-wide (914 mm) underlayment of either one layer of Type I underlayment running the full length of the valley or a self-adhering polymer-modified bitumen sheet complying with ASTM D 1970, in addition to other required underlayment. In areas where the average daily temperature in January is 25°F (-4°C) or less or where there is a possibility of ice forming along the eaves causing a backup of water, the metal valley flashing underlayment shall be solidly cemented to the roofing underlayment for slopes under seven units vertical in 12 units horizontal (58-percent slope) or self-adhering polymer-modified bitumen sheet shall be installed.
1507.10 Built-up roofs. The installation of built-up roofs shall comply with the provisions of this section.

1507.10.1 Slope. Built-up roofs shall have a design slope of a minimum of one-fourth unit vertical in 12 units horizontal (2-percent slope) for drainage, except for coal-tar built-up roofs that shall have a design slope of a minimum one-eighth unit vertical in 12 units horizontal (1-percent slope).
1507.10.2 Material standards. Built-up roof covering materials shall comply with the standards in Table 1507.10.2.

TABLE 1507.10.2 BUILT-UP ROOFING MATERIAL STANDARDS


MATERIAL STANDARD
STANDARD
Acrylic coatings used in roofing ASTM D 6083
Aggregate surfacing ASTM D 1863
Asphalt adhesive used in roofing ASTM D 3747
Asphalt cements used in roofing ASTM D 3019; D 2822;
D 4586
Asphalt-coated glass fiber base sheet ASTM D 4601
Asphalt coatings used in roofing ASTM D1227; D 2823;
D 4479
Asphalt glass felt ASTM D 2178
Asphalt primer used in roofing ASTM D 41
Asphalt-saturated and asphalt-coated organic felt base sheet ASTM D 2626
Asphalt-saturated organic felt (perforated) ASTM D 226
Asphalt used in roofing ASTM D 312
Coal-tar cements used in roofing ASTM D 4022; D 5643
Coal-tar saturated organic felt ASTM D 227
Coal-tar pitch used in roofing ASTM D 450; Type I or II
Coal-tar primer used in roofing, dampproofing and waterproofing ASTM D 43
Glass mat, coal tar ASTM D 4990
Glass mat, venting type ASTM D 4897
Mineral-surfaced inorganic cap sheet ASTM D 3909
Thermoplastic fabrics used in roofing ASTM D 5665, D 5726
1507.11 Modified bitumen roofing. The installation of modified bitumen roofing shall comply with the provisions of this section.

1507.11.1 Slope. Modified bitumen membrane roofs shall have a design slope of a minimum of one-fourth unit vertical in 12 units horizontal (2-percent slope) for drainage.
1507.11.2 Material standards. Modified bitumen roof coverings shall comply with CGSB 37-GP-56M, ASTM D 6162, ASTM D 6163, ASTM D 6164, ASTM D 6222, ASTM D 6223, ASTM D 6298 or ASTM D 6509.
1507.12 Thermoset single-ply roofing. The installation of thermoset single-ply roofing shall comply with the provisions of this section.

1507.12.1 Slope. Thermoset single-ply membrane roofs shall have a design slope of a minimum of one-fourth unit vertical in 12 units horizontal (2-percent slope) for drainage.
1507.12.2 Material standards. Thermoset single-ply roof coverings shall comply with ASTM D 4637, ASTM D 5019 or CGSB 37-GP-52M.
1507.12.3 Ballasted thermoset low-slope roofs. Ballasted thermoset low-slope roofs (roof slope < 2:12) shall be installed in accordance with this section and Section 1504.4. Stone used as ballast shall comply with ASTM D 448.
1507.13 Thermoplastic single-ply roofing. The installation of thermoplastic single-ply roofing shall comply with the provisions of this section.

1507.13.1 Slope. Thermoplastic single-ply membrane roofs shall have a design slope of a minimum of one-fourth unit vertical in 12 units horizontal (2-percent slope).
1507.13.2 Material standards. Thermoplastic single-ply roof coverings shall comply with ASTM D 4434, ASTM D 6754, ASTM D 6878 or CGSB CAN/CGSB 37-54.
1507.13.3 Ballasted thermoplastic low-slope roofs. Ballasted thermoplastic low-slope roofs (roof slope < 2:12) shall be installed in accordance with this section and Section 1504.4. Stone used as ballast shall comply with ASTM D448.
1507.14 Sprayed polyurethane foam roofing. The installation of sprayed polyurethane foam roofing shall comply with the provisions of this section.

1507.14.1 Slope. Sprayed polyurethane foam roofs shall have a design slope of a minimum of one-fourth unit vertical in 12 units horizontal (2-percent slope) for drainage.
1507.14.2 Material standards. Spray-applied polyurethane foam insulation shall comply with Type III or IV as defined in ASTM C 1029.
1507.14.3 Application. Foamed-in-place roof insulation shall be installed in accordance with the manufacturer's instructions. A liquid-applied protective coating that complies with Section 1507.15 shall be applied no less than 2 hours nor more than 72 hours following the application of the foam.
1507.14.4 Foam plastics. Foam plastic materials and installation shall comply with Chapter 26.
1507.15 Liquid-applied coatings. The installation of liquid-applied coatings shall comply with the provisions of this section.

1507.15.1 Slope. Liquid-applied roofs shall have a design slope of a minimum of one-fourth unit vertical in 12 units horizontal (2-percent slope).
1507.15.2 Material standards. Liquid-applied roof coatings shall comply with ASTM C 836, ASTM C 957, ASTM D 1227 or ASTM D 3468, ASTM D 6083, ASTM D 6694 or ASTM D 6947.
1507.16 Roof gardens and landscaped roofs. Roof gardens and landscaped roofs shall comply with the requirements of this chapter and Sections 1607.11.2.2 and 1607.11.3.