Various Flat Roof Material Options
We love the flexibility of a flat roof for certain design limitations but they have a bit of problem reputation for leaks and repairs Of course flat roofs are not really flat, but have a very slight roof pitch of between 1/4″ to 1/2″ per foot. Just enough slope to drain water but also flat enough to be a problem if not constructed properly.
The good news is that there are material options for your flat roof beyond traditional hot-mopped built up roofing that will increase the reliability of the flat roof. Let’s review the most common categories of flat roof materials available for your home:
- Single Layer Membrane Roof
- Modified Bitumen Roof
- Built Up Roof (BUR)
Single Layer Membrane Roof:
The membrane roof is the latest roofing technology and is also the roof of choice in commercial construction. Known technically as elastomeric or plastomeric roof membrane (depending on the material), single-ply roofs come in a few different varieties including:
- Neoprene (polychloroprene):
- EPDM (ethylene propylene diene monomer)
- PVC (polyvinyl chloride)
- Chlorinated polyethylene and chlorosulfonated polyethylene sheets
- Polymer-modified bitumens
Of all these membrane types EPDM, a synthetic rubber, is the most common single-ply membrane roof material in both residential and commercial use. So all you really need to be able to say to your roof contractor is you want an EPDM rubber roof. These roofs are installed as thin sheet materials 0.030 (30 mils) to 0.060 inches (60 mils) thick, and are applied to the roof in a single layer. Being made of synthetic rubber or polymer, they are flexible and elastic and are able to handle temperature changes and some impact types better than built up roofs.