Section 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 one-forth unit vertical in 12 units horizontal (2-percent slope) for drainage.

1507.13.2 Material standards. Thermoplastic single-ply roof coverings shall comply with ASTM D 4434, ASTM D 6754, ASTM D 6878 or CAN/CGSB 37-54.

Code Interpretation

This is the standard code requirement for low-slope roof materials. The code implies that low-slope roof materials shall be applied on a roof deck that has a minimum slope of 1/4 inch per foot and that it must have positive drainage. Proper roofing procedures require that all ponding water must drain off of the roof surface within 48 to 72 hours after a rainfall.

The code also provides the physical property testing requirements that the roof materials/system must meet. The code specifies that the materials must be tested in accordance with the requirements of the standard American (ASTM) and Canadian (CAN/CGSB) material testing organizations. Standard membrane test requirements include measurement of mil thickness, tensile/elongation, weathering, and puncture resistance. Liquids and coating materials are subjected to viscosity testing and reflectance ratings.