Slope Of Membrane Roof

Roof coating and membranes serve a vital purpose for buildings and enclosures with flat roofs.

Slope of membrane roof.

The minimum roof slope allowed by code for any type of roof is in 12 applicable only to coal tar pitch roof systems. This system can be used for a large number of projects including home expansions cabins garages annexes carports sheds and workshops. When we say flat roof we don t mean perfectly flat which is undesirable since water still needs to be shed to roof drains. Some tpo membrane assemblies also have relatively low maximum roof slope limitations.

So the pitch of a roof is determined by how many inches the slope rises for every 12 inches it runs horizontally. For this type of roof shingles and other traditional coatings are less durable and less aesthetic. Pvc membrane assemblies generally have higher maximum roof slope limitations. Technically we are talking about low slope roofs that have a slope less than or equal to 3 12.

As a building owner it can be helpful for you to understand the characteristics of the roof membranes on your building. Epdm is the most common membrane and is a black synthetic rubber roof membrane. Thermoplastic single ply membrane roofs must have a design roof slope of 1 4 12 or greater 2 slope. These membranes are particularly effective for roofs with a very low slope between 1 8 12 1 and 4 12 33.

The following table provides the minimum required allowable roof slope for each type of roofing material mentioned in the code. The different types of coverings can be overwhelming and confusing so here is a breakdown of the basics for each one. This means for every 12 horizontal units the roof must rise a minimum of one fourth vertical unit. Modified bitumen roof coverings shall comply with cgsb 37 gp 56m astm d6162 astm d6163 astm d6164.

When it comes to low slope roof membranes there are differences you should be aware of. The ponds will do nothing but lead to siltation which will create stress on the roof membrane causing the distraction of the roof cover. Formation of ponds on flat roofs is detrimental to the longevity and effectiveness of the roof. Modified bitumen membrane roofs shall have a design slope of not less than one fourth unit vertical in 12 units horizontal 2 percent slope for drainage.

Membranes and coatings are designed to create a strong seal to prevent leak when water begins to build. Minimum slope for a membrane roof. Epdm roof membrane can be secured in a number of ways. Sprayed polyurethane foam roofing minimum roof slope roof pitch r905 14 1.