Liquid EPDM (aka "liquid roof")


#1

I see all these websites selling “liquid roof” or “liquid rubber” - supposedly a cold applied EPDM membrane (2 part with catalyst). There are many vendors but the product seems to all be the same.

Is this stuff any good? I can’t find a single independent review or even a single person who’s actually tried or even seen it. Positive or negative. It appears to have been around a few years now, so I’d think SOMEONE would have an opinion on it?

I guess in concept it sounds good? I have a 100-percent flat roof with leaking (but physically intact) polyurathane spray foam. I’d like to keep it in place as it provies an inch of insulation. The liquid EPDM sounds like a good application for it?

So is this stuff any good, or snake oil? Anyone actually used it or heard from someone who has?
Thanks! Josh


#2

The typical liquid EPDM or Polyurethane roof systems are ok. Any good system applied in enough layers or “coats” will provide a few good years of service. Of course, good prep work is essential, and your surface has to be clean and dry.

Going over your sprayfoam is a gamble. If your roof is in fact dead flat, you would be far better off to go with a complete removal of the existing foam, install new Polyiso foam for a better insulating value, and a good TPO or PVC membrane roof that will last 20 years.

Remember, coatings are just that… coatings. You may get a few years out of them, but you’ll be back with the same problem before you know it. I wouldn’t recommend going the liquid roof route, just my opinion.