Elastomeric Roof Coating

Sally · Mon Sep 15, 2008 2:47 pm

Anybody have an opinion on those white, elastomeric roof coatings? I live in southwest Georgia and it is terrifically hot and humid here. I'm looking to put something on my roof which will refract light away from the dwelling and hopefully keep the interior cooler (and the utility bill smaller). Does this stuff work?

flcruising · Mon Sep 15, 2008 4:02 pm

Any light colored roof will reduce the heat-gain through the roof system.

Elastomeric is simply a high-build paint, so like most any other exterior painted surface, expect it to need recoating every few years.

What type of roof finish is there now? Asphalt shingle? Metal?

Greg · Mon Sep 15, 2008 5:45 pm

I can tell you that kool coat did make a difference in our home this summer. I don't have the money facts to back it up, but I could feel the difference. Greg

Sally · Tue Sep 16, 2008 8:17 am

Thanks for the replies!

The roof appears to be asphalt shingle (or whatever passes for asphalt shingle in a mobile home.) I've calculated that it will take three 5-gallon buckets of this elastomeric to coat the roof one time.

Is it necessary to use "elastomeric," or would any exterior white paint produce the same result?

Greg · Tue Sep 16, 2008 5:49 pm

Check with the manufacturer before using on asphalt, there may be a problem going over it and having it stick to it. Greg

JD · Tue Sep 16, 2008 6:50 pm

I would highly recommend that you don't coat asphalt shingles. Some elastomerics can be used successfully on rolled asphalt roofing, but we are talking 5-6 coats of material and the use of the right primer to stabilize the mineral surface. The use of roof fabric between the undercoats and top coats is also recommended. Elastomeric on shingles will crack from the movement and UV rays. When it cracks, it cracks at the bottom edge of the shingle, creating dam effect that will hold water and cause it to travel sideways.

JMO
JD