Roofing Code: Section 1507

Roofing

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.

Code Interpretation

This section implies that the application of asphalt shingles can only occur on roofs with slopes of 2:12 or greater. Underlayments are required on all asphalt shingle applications. If the slope of the roof is between 2:12 and 4:12 — considered a low-slope roof — then a minimum of two layers of underlayment is required. Underlayment application shall be in accordance with Section 1507.2.8.

Shingle attachment shall be with approved nails and not less than four (4) fasteners for strip shingles and two (2) fasteners for individual shingles. A minimum of six (6) fasteners is required for shingles in high-velocity wind zones.

Waterproofing Code: Section 1807

Dampproofing and Waterproofing

1807.3.2.1 Surface Preparation of Walls. Prior to the application of waterproofing materials on concrete or masonry walls, the walls shall be prepared in accordance with Section 1807.2.2.1.

Code Interpretation

This section implies that the wall substrate must be properly prepared to receive waterproofing materials. The wall must be free of all voids, openings, cracks, honeycombs, fissures and other imperfections prior to the application of the waterproofing material.

Concrete walls can be repaired using bituminous materials or other products approved by the material manufacturer.

Masonry walls shall be parged below ground level on the exterior surface using not less than 0.375 inches (9.5 mm) of Portland cement. The only exception is approved for application directly to the masonry.