This new question is related to this old question I had previously asked, but from another point-of-view.

I have a 13ft x 13ft rooftop made from plain concrete. It's leaking a bit, so I have to do something about it. I was going to do it on my own, but decided to hire a professional... for now.

I called several contractors, and they all work with bituminous (or asphalt) membrane rolls that are installed with a torch. I asked a few of them if they can apply a product applied with a roller, but they make a point of telling me that they only work with asphalt membranes. Unfortunately, the estimates are very high.

So these is what they will do:

  1. wash roof with power washer
  2. Apply primer with roller
  3. Apply bituminous/asphalt membrane rolls with torch

Few people (if any) walk through this 13'x13' area, so I'm not sure if this membrane is overkill.

I guess my question is, is there anything as "thick" as the membrane that can be rolled on and that may also cover up any defects in the concrete?

I really like the idea of this membrane, because it's almost like a "carpet" that will cover the concrete and any ugly details the the floor may have. On the downside, this product is quite expensive and the labor is ever more expensive.

Btw, we live in the Caribbean and it cannot be the reflective white that hurts your eyes when looked at directly. Also, I don't mind the surface getting warmer.

  • There are acrylic latex membranes that can be brushed or sprayed on and used with glass-fibre reinforcement to cover defects
    – Jasen
    Feb 12, 2020 at 19:20
  • I like torch on membrane. It can be walked on and lasts a long time 35+ years. We used it in very rainy environments typically two layers thick. You typically still want some slope to the area so you don't have water ponding. Does the existing roof have slope to it? I would NOT trust a roll-on membrane. If you can find a roll on that you apply peel up and takes as much force to rip as a roll of the torch on membrane then I'd re-evaluate my opinion. Feb 12, 2020 at 19:30
  • You could do EPDM but the seams are tricky and I suspect the cost would be more than torch on. Feb 12, 2020 at 19:31
  • EPDM is a better alternative if you are not walking on it, if I remember you require light foot traffic, I don’t think bituminous will hold up as a sealer for foot traffic and on hot days you may not be very happy with the surface. I would revisit cleaning and sealing as suggested.
    – Ed Beal
    Feb 12, 2020 at 22:08

2 Answers 2


There are several "rubber" roof materials for flat roofs; neoprene, EDPM, butyl, TPO, etc. Search "rubber roof" on the net for your location to find out what is available , what is needed for your UV, temperature, etc , and what is required for installation. I have EDPM pond liner; small parts of it have been exposed to weather for 20+ years and seem to be "good as new".


There are products around that you can paint on such as this one:
Gorilla WaterStop 1000 Waterproof Repair

It's a stretchable fibre reinforced paint on product and can seal across small gaps. If the gap is bigger than 2mm then a mesh reinforcing tape needs to be used before the product is applied.

I've also purchased a bitumen based products in the past. These were found by asking around at the local hardware store. I found those suitable for sealing up smaller leaks in spouting and downpipes. The waterstop style product might be more suitable in your case.

I had a leak in my roof recently and purchased Waterstop from a local plumbing store. If you can't obtain this exact product I'm sure you'll find other similar products produced by brands available in your area.

It was not expensive.


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