Slope Of Membrane Roof

Modified bitumen roof coverings shall comply with cgsb 37 gp 56m astm d6162 astm d6163 astm d6164.

Slope of membrane roof.

Technically we are talking about low slope roofs that have a slope less than or equal to 3 12. Sprayed polyurethane foam roofing minimum roof slope roof pitch r905 14 1. This means for every 12 horizontal units the roof must rise a minimum of one fourth vertical unit. This system can be used for a large number of projects including home expansions cabins garages annexes carports sheds and workshops.

The different types of coverings can be overwhelming and confusing so here is a breakdown of the basics for each one. Roof coating and membranes serve a vital purpose for buildings and enclosures with flat roofs. It is imperative that the right slope for the flat roof be adopted to avoid all these potential problems. If a roof increases in height by four inches for every foot of horizontal run it is considered to have a 4 in 12 pitch or just a 4 pitch talk in terms of pitches and you will always be understood in the roofing universe.

When it comes to low slope roof membranes there are differences you should be aware of. Epdm roof membrane can be secured in a number of ways. 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 ponds will do nothing but lead to siltation which will create stress on the roof membrane causing the distraction of the roof cover. For this type of roof shingles and other traditional coatings are less durable and less aesthetic. Formation of ponds on flat roofs is detrimental to the longevity and effectiveness of the roof.

Minimum slope for a membrane 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. Pvc membrane assemblies generally have higher maximum roof slope limitations. The minimum roof slope allowed by code for any type of roof is in 12 applicable only to coal tar pitch roof systems.

As a building owner it can be helpful for you to understand the characteristics of the roof membranes on your building. Some tpo membrane assemblies also have relatively low maximum roof slope limitations. For example some epdm membrane assemblies have maximum roof slope limitations as low as 1 2 12. When we say flat roof we don t mean perfectly flat which is undesirable since water still needs to be shed to roof drains.