The following low slope roof system discussion is adapted paraphrased with permission from best practices guide to residential construction chapter on best roofing practices.
Roof low pitch options.
Keep in mind that neither metal shingles not corrugated metal panels are suitable options for low slope or nearly flat roofs.
For a low slope residential roof there are two main options.
Suitable materials for pitched roofs.
This top layer normally is tar over which the gravel is laid.
For commercial buildings one of the other popular low pitch roof options is coated metal.
1 cover the entire surface with a self adhesive flashing membrane such as grace ice water shield there are many.
Table of low slope roofing options.
2 where the roof is not visible consider upgrading to a single ply roofing intended for low slope roofs.
5 12 to 12 12 pitch.
This coating helps reduce the instances of rust increasing the life span of the roof.
These shingles are appropriate for pitches as low as 4 12 pitch all the way up to a 12 12 pitch.
Metal roofs aren t waterproof in and of themselves but they can be treated with a coating that makes them so.
Think of them as taking the middle road in terms of roof pitch not too flat not too steep.
Pitched roofs begin with with slopes greater than 3 in 12.
Pros cons of roll roofing bur modified bitumen epdm roof systems.