Minimum Slope For Membrane Roof

Asphalt shingles continue to be the most widely installed roof covering option in north america.

Minimum slope for membrane roof.

The idea is to provide positive drainage toward roof drains so there is no ponding water 48 hours after a rain storm. The following table provides the minimum required allowable roof slope for each type of roofing material mentioned in the code. Many building codes have a slope requirement for membrane roof systems. Install the membrane horizontally starting at the bottom of the slope.

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 minimum roof slope allowed by code for any type of roof is in 12 applicable only to coal tar pitch roof systems. Unroll and position the roll. This 1 4 12 minimum roof slope requirement also applies to spray polyurethane foam spf roof.

The minimum roof slope for metal roofs is dependent upon the roof profile. This means for every 12 horizontal units the roof must rise a minimum of 2 vertical units. International building code 2012 edition ibc 2012 section 1507 require ments for roof coverings states all membrane roof covering systems except coal tar built up roofs have a design slope minimum of one fourth unit vertical. 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.

Minimum pitch for metal roof. The 12 year weatherbond warranty is to date the best i ve found in the category of residential low slope roofing products. With regards to metal roofing the profile refers to the shape adopted by the metal sheets when they are bent to form the panels. They provide excellent weather resistance great value and now more than ever a tremendous range of beautiful designs and color blends.

The international codes i codes are the widely accepted comprehensive set of model codes used in the us and abroad to help ensure the engineering of safe sustainable affordable and resilient structures. To get the minimum pitch for a metal roof the vertical rise per foot is divided by the horizontal slope. Asphalt shingles minimum roof slope roof pitch r905 2 2. The short simple answer is 2 12 has traditionally been considered the absolute minimum acceptable roof slope suitable for asphalt shingles.

All nails must be covered with a membrane. And if the performance of single ply epdm roofing on commercial installations is any measure weatherbond 110 can certainly last much longer than 12 years if it s properly installed.