# Spray foam insulation of roof deck



## user182 (Jan 17, 2009)

What happens to an insulated roof deck it when to comes time to replace the shingles and bad wood is found? 

The insulation will be damaged when the decking is removed.

If there are any gaps in the insulation moisture will migrate into that area and rot the wood.

Most of the people promoting this are dealing in theory not reality.

I inspected one of these insulation jobs on a bungalow style roof. It was not air tight at the point where the slanted ceiling starts directly above the kneewall. This will allow humidity into the unvented area.

The whole thing is a bad idea.

After my consultation the person I did the inspection came to the conclusion that the entire deck and insulation should be removed.


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## Grumpy (Oct 29, 2008)

In theory it's a great idea. I've never been witnesses to a job that was more than a few days old. It's been going on for 10 or more years though, just not very common around here.


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## English Roofer (Dec 26, 2008)

I worked for a company that did the spray foam on to the back of a slate or tiled roof that didnt have any sarking felt(underfelt wasnt used here till the early 60's) any way it was my job to repair all the broken slates/tiles before the sprayers came along inside.
I lasted 2 weeks before me and my soul lost the will to live!
Ive come accross them since when asked to do some repaire and there a bugger to get out!!! the price for the job definately goes up.
Ive never had the pleasure of having to re-roof one and im not sure i would ever want too!
Cheers
Dave


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## urethaneroofer (Jul 2, 2009)

*foam insulation*

Foam insulation is the best money can buy N.A.S.A. uses it on the space shuttle fuel tanks. If it's good enough for N.A.S.A. it's good enough for your house.

"If there are any gaps in the insulation moisture will migrate into that area and rot the wood".

The problem is not with the foam it's a problem with the applicator. (most of which are not qualified to spray it.) As for rotted wood your right if the wood gets to that point you will have to re-apply the foam.(the money saved in your energy bill will more than pay for that re-application of foam) But if you are doing PREVENTITIVE roof maintenence you should never have rotted wood after you've spent all that money insulating your home and putting on a new roof. 

Thats part of the roofing indrustrys problem. We give people the false sense that you can put a new roof on and it's a twenty year roof out of sight out of mind. Educate your consumers. Tell them the truth The roof is a 20 year roof but you need bi-yearly inspections and regular maintenence. 

I can spray 6000 lbs in one day thats 181 square with one labor Can you see the $20 bills flying out of the end of the foam gun now? I've sprayed well over 1,000,000 lbs of the stuff. And have had only minimal problems with it.

I see this all the time


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## Grumpy (Oct 29, 2008)

I think jack was talking about on a shingle roof which is a whole other beast from flat roofing. Nasa doesn't use it to insulate their attics, I don't think.


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## AaronB. (Nov 23, 2008)

You never know, Grumpy, they might. If they were smart they would.

I heart urethane foam!!!


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## robert (Oct 29, 2008)

Why is it i always hear they use it on the space shuttle its great?Wasnt it the cause of the challenger diaster?Not bashing SPF here because i know it is a good roof system when properly installed,but very few people do it right!


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## urethaneroofer (Jul 2, 2009)

Your Right Robert, very few foam applicators are qualified to even step foot into a foam rig let alone spray the stuff. Personally I think an applicator should watch it sprayed by a qualified applicator for at least 1 year before he even get's to clean the gun! This is what a quality foam roof should look like http://arizonaroofer.net/my-project-photos-2/?album=1&photo=28


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## robert (Oct 29, 2008)

Nice work,i once watched a guy spray a hotel here he was with centimark and his work was impeccable. He actually sloped the roofs to drain as they were sloped into roof drains, very nice work. But we have another local guy spraying his roofs look like the surface of the moon when hes done and a few have been removed because of leaks.


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