Liquid EPDM (aka "liquid roof")


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


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.