How to put EPDM on concrete flat roof?
by
Mawhelan16
+4
I have a shed with a concrete roof approx 14' x 8'.
I want to put an EPDM rubber roof on it.
I first want to affix OSB sheets to it - but on battens.
I need to know if it needs to be damp proofed prior to affixing battens.
Thank you in advance.
You can use a clear concrete sealer just for added protection and prevent it from breaking down in the future. Spalling, flaking, etc. Make sure the battens are pressure treated for moisture resistance.
Thanks.
To add to Williams’ point, Make sure the battens make a significant amount of slope increase. Another one percent, or even 2% will make all the difference in the world.
As you know OSB is not water resistant, and I don’t believe it’s available in an exterior grade. So I’d make sure all the exposed edges are not only flashed but also counter-flashed in some areas.
We use OSB sheeting for walls & roofs (pitched) on Habitat for Humanity projects. All of these have moisture barriers and siding/asphalt shingles. As stated above, ensure you build in a slope per local codes and weather expectations.
Butyl MS Caulk is the ideal sealant for caulking the concrete first. It has the wide range of applications, solvent free, can be applied at low temperatures and on wet surfaces also. Then, apply a flash coat of EPDM liquid butyl rubber that has the life expectancy of more than 18 years. It gives you the best alternative to costly roof replacement at a fraction of cost giving a hard, finish, reflective white and aesthetically pleasing look when completely dry.