Roofing & Waterproofing Codes - Codes - Architectural Roofing and Waterproofing

Roofing Code: Chapter 15

Roofs and Roof Structures

Section 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 1/4 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.

Code Interpretation:

Thermoset roof classifications include rubber polymer sheets such as EPDM and butyl rubber. This section implies that thermoset roof systems shall be applied on roof substrates that have a minimum slope of 2 percent (1/4 inch in 12 inches). Proper roofing industry standards require that the slope of the deck shall be sufficient to remove all standing water from the roof system a maximum of 48 hours after a rainfall. The roof deck slope must comply with IBC requirements (1/4 inch in 12 inches). If this slope is not adequate to remove all standing water from the system, artificial means (such as tapered insulation) may be required.

The section also implies that the thermoset materials must meet the requirements set forth by ASTM (American) or CGSB (Canadian) standards for physical property testing. Physical property tests typically include moisture resistance, tensile, elongation, mil thickness, accelerated weathering and wind uplift testing.

Waterproofing Code: Chapter 18

Dampproofing and Waterproofing

Section 1807.1.2, Under-Floor Space:

The finished ground level of an under-floor space such as a crawl space shall not be located below the bottom of the footings. Where there is evidence that the ground-water table rises to within 6 inches (152 mm) of the ground level at the outside building perimeter, or that the surface water does not readily drain from the building site, the ground level of the under-floor space shall be as high as the outside finished ground level, unless an approved drainage system is provided. The provisions of Sections 1802.2.3, 1807.2, 1807.3 and 1807.4 shall not apply in this case.

Code Interpretation

This section implies that an under-floor space — such as a crawl space — shall not be located below the bottom of the foundation.

This section also implies that the under-floor space shall be at ground level if:

• The water table rises to within 6 inches of the ground level.

• The water does not drain from the site unless an approved drainage system is installed.