Minimum Slope For Single Ply Membrane Roofing

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.

Minimum slope for single ply membrane roofing.

Astm d4637 standard specification for epdm sheet used in single ply roof membrane. These membranes are particularly effective for roofs with a very low slope between 1 8 12 1 and 4 12 33. Sprayed polyurethane foam roofing. 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.

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. Thermoplastic single ply roofing minimum roof slope roof pitch r905 13 1. Heat welded seams provide superior strength. This means for every 12 horizontal units the roof must rise a minimum of one fourth vertical unit.

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. Higher density products provide improved impact resistance. 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. The idea is to provide positive drainage toward roof drains so there is no ponding water 48 hours after a rain storm.

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. Thermoplastic single ply membrane roofs must have a design roof slope of 1 4 12 or greater 2 slope. This 1 4 12 minimum roof slope requirement also applies to spray polyurethane foam spf roof. The use of the resisto self adhered waterproofing membrane as a first layer and the resisto granulated cap sheet high resistance hr cap sheet as a second layer is an ideal solution to ensure the waterproofing of low slope roofs.

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. The slope of the roof must not be less than 1 12 8. 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. Short for thermoplastic polyolefin tpo is a single ply roofing membrane that offers excellent performance at a cost effective price.