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Gravel over spray foam roofing Post New Topic | Post Reply

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Robert Wilson
Posted: Oct 04, 2012 06:04 PM
Gravel over spray foam roofing
I was wondering if it's possible to put gravel over foam.
We normally remove the gravel before applying foam but this job is going to be very hard to remove the gravel . So I want to know if I could move half the gravel to one side of the roof clean foam and coat and move all the gravel to that side and clean foam and coat then spread the gravel evenly over the roof. Let me know if anyone has done this?

Dennis Davidson
Posted: Oct 09, 2012 07:39 PM
NCFI has a gravel/foam roof systems called "EnduraRock". We installed several back in the 80's and as far as I know there all still in good shape. Find out if the roof structure can hold the extra weight when moving gravel from one side to the other.
It would be far cheaper to have a gravel vac crew come in and remove it for you. Faster, cheaper and much cleaner!
Posted: Oct 10, 2012 01:23 PM
The gravel has to be a specific size and be crushed rock not round pebbles. SPFA has a guideline for aggregate covered spray foam roofing. I think it is either AY 110 or AY 111. (one is the aggregate guideline, the other is cold storage.

You coat all protrusions and edges, a lot of contractors use it in cold climates where coating takes longer to cure.
Gerry Wagoner
Posted: Dec 10, 2012 01:06 PM
We have used GraveledFoam for many years. Good success with it as long as the roof has decent drainage. Ponded water and GraveledFoam does not make for a good experience.

Use #8 limestone or #7 if you can get them. 57's work well if you have a concrete deck that can sustain the extra weight.

Have fun.

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