Minimum Slope For Single Ply Membrane Roofing

Thermoplastic single ply roofing minimum roof slope roof pitch r905 13 1.

Minimum slope for single ply membrane roofing.

Higher density products provide improved impact resistance. A minimum slope of 0 25 inches per foot 2 percent is recommended for all low slope roofing systems for adhered systems the substrate must be one that is approved by the system supplier. Table 1 01 1 chart of roofing system applicability thermoplastic single ply membranes back nailing table 1 03 1 back nailing requirement for sloped roofs table 1 04 1 the minimum fastener pullout resistances for specific systems. This means for every 12 horizontal units the roof must rise a minimum of one fourth vertical unit.

Unique in the industry duro last offers a 15 year warranty with consequential damage coverage for duro last prefabricated roofing systems with no additional charge. Short for thermoplastic polyolefin tpo is a single ply roofing membrane that offers excellent performance at a cost effective price. This warranty applies to low slope roofs that use the outer perimeter instead of a drain to evacuate water. The minimum slope for a flat roof is 1 4 per foot or 1 4 12 but some owners or insurance companies require a minimum slope of 1 2 per foot.

This 1 4 12 minimum roof slope requirement also applies to spray polyurethane foam spf roof. Thermoplastic single ply membrane roofs must have a design roof slope of 1 4 12 or greater 2 slope. Apply a single ply adhesive that will adhere to the existing membrane as a primer thick enough to accept a full broadcast of 16 grit silica sand or granules. For example the international building code 2018 edition ibc 2018 prescribes a 1 4 12 minimum roof slope for asphalt built up polymer modified bitumen thermoset and thermoplastic single ply and liquid applied membranes in new construction.

Single ply membrane has a weft insertion anti wicking scrim with a density of 18 by 14 threads per inch among the highest in the industry. Tpo s long term heat uv and natural fungal resistance plus flexibility without need for plasticizers also make tpo a reliable low slope roofing system. The idea is to provide positive drainage toward roof drains so there is no ponding water 48 hours after a rain storm. The slope of the roof must not be less than 1 12 8.

These membranes are particularly effective for roofs with a very low slope between 1 8 12 1 and 4 12 33. Heat welded seams provide superior strength. Astm d4637 standard specification for epdm sheet used in single ply roof membrane. Roofing membranes that are single ply such as a pvc tpo or epdm requires a thin layer of a compatible single ply adhesive to be used as a primer for roofslope.