Thread: Foam Roof Material

Can anybody give me any real life recommendations on what to be concerned about or look for or typical deficiencies of a foam roof? Does anybody have experience with this material? Is it allowed to be installed directly against gas B vents? There was a leak detected inside the house so I am recommending a roofing contractor anyhow, but wanted to get some ideas and info from the message board. See photos.

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Sorry, Here are the photos

Matthew,

Foam roofs rely on a rather thin membrane that is essentially painted on. That membrane wears through rather rapidly, at least in my experience. However, I have been told (no personal experience) that it is relatively easy to recoat. There is supposed to be a felt paper layer between the foam and the roof deck, but this is not going to be waterproof.

I don't often see foam roofs, but when I do, there are usually holes in the membrane and exposed foam and uneven/improperly sloped areas that will hold water.

Standard flashing details similar to asphalt & gravel roofs are required. As you surmised, that b-vent is wrong. The cap flashings don't look too good either.

What Gunnar said.

The top coating is supposed to be at least 50 mils thick, in at least two (or maybe it's three) coats.

Most often, the top coating is only (at most) 20 mils thick, which allows it to fail sooner (rather than later as it would if it were 50 mils thick).

Once the top coating has failed, sunlight deteriorates the foam and water enters.

You now have water under the waterproofing membrane, which means it is not going to evaporate, it is going to get all soggy wet and migrate downhill to where it can leak through.

Did I imply that those roofs are crap?

If not, or if that was not clear, those roofs are, in my opinion, crap.

Matthew. Where are you from? Update profile.

B vents yes also plumbing vents, However some times the foam covers the inspide of plumbing vents causing insufficient venting.

The foam last a long time if sealed every 3-4 years (no longer)

Rolland Pruner

Originally Posted by Matthew Barnicle

Is it allowed to be installed directly against gas B vents?

No, there would need to be a proper flashing around the B vent, and the roof, like all roofing, would go to the flashing.