X-C-IBC_Slate_1507.7-icod_ibc_2012_1.pdf

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.

1507.7.3.1 Underlayment and high wind.

Underlayment applied in areas subject to high winds [Vasd greater than 110 mph (49 m/s) as determined in accordance with Section 1609.3.1] shall be applied with corrosion-resistant fasteners in accordance with the manufacturer's installation instructions. Fasteners are to be applied along the overlap not farther apart than 36 inches (914 mm) on center.

Underlayment installed where Vasd, in accordance with Section 1609.3.1, equals or exceeds 120 mph (54 m/s) shall comply with ASTM D 226 Type II or ASTM D 4869 Type IV. The underlayment shall be attached in a grid pattern of 12 inches (305 mm) between side laps with a 6-inch (152 mm) spacing at the side laps. Underlayment shall be applied in accordance with the manufacturer's installation instructions except all laps shall be a minimum of 4 inches (102 mm).

Underlayment shall be attached using metal or plastic cap nails with a head diameter of not less than 1 inch (25 mm) with a thickness of at least 32-gauge [0.0134 inch (0.34 mm)] sheet metal. The cap nail shank shall be a minimum of 12 gauge [0.105 inch (2.67 mm)] with a length to penetrate through the roof sheathing or a minimum of 3/4 inch (19.1 mm) into the roof sheathing.

Exception: As an alternative, adhered underlayment complying with ASTM D 1970 shall be permitted.

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)

Page 1 of 2Chapter 15 - Roof Assemblies and Rooftop Structures

3/30/2015http://publicecodes.cyberregs.com/icod/ibc/2012/icod_ibc_2012_15_sec007.htm

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).

4:12 < slope < 8:12 4

8:12 < slope < 20:12 slope ≥ 20:12 2

For SI: 1 inch = 25.4 mm.

Page 2 of 2Chapter 15 - Roof Assemblies and Rooftop Structures

3/30/2015http://publicecodes.cyberregs.com/icod/ibc/2012/icod_ibc_2012_15_sec007.htm