Membrane Roofing Minimum Slope

Maximum slope mechanically attached system.

Membrane roofing minimum slope.

Heat welded seams provide superior strength. The criterion for judging proper slope for drainage is that there be no ponding water on the roof 48 hours after a rain during conditions conducive to drying many building codes have a slope requirement for membrane roof systems. For this type of roof shingles and other traditional coatings are less durable and less aesthetic. Building codes generally provide prescriptive minimum roof slope requirements for various roof system types.

Run in degrees and as percentage the minimum roof slope allowed by code for any type of roof is in 12 applicable only to coal tar pitch roof systems. Short for thermoplastic polyolefin tpo is a single ply roofing membrane that offers excellent performance at a cost effective price. The following table provides the minimum required. 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.

The maximum recommended roof slope for mechanically attached roofing systems is 18 in one horizontal foot. This 1 4 12 minimum roof slope requirement also applies to spray polyurethane foam spf roof systems in new construction. Thermoplastic single ply membrane roofs must have a design roof slope of 1 4 12 or greater 2 slope. Larger flat roofed applications low slope such as residential condominium complexes row homes and town houses and smaller applications such as residential porch and garage transitions from the main home where the slope of the roof changes dramatically.

1 16 12 in 12. Residential low slope roofing can generally be divided up into two broad categories. 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. The nrca roofing manual.

Roof slope equivalents as rise. There are no maximum slope restrictions for the application of the fully adhered roofing system. Minimum slope for a membrane roof when we say flat roof we don t mean perfectly flat which is undesirable since water still needs to be shed to roof drains. Sprayed polyurethane foam roofing minimum roof slope roof pitch r905 14 1.

Ponding is defined as water that has not drained or dissipated within 48 hours after rainfall. Membrane roof sys tems 2011 states. Technically we are talking about low slope roofs that have a slope less than or equal to 3 12. Finding the right products for your low slope roof.

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.