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Author	Comments
kevin smith Posted: Apr 15, 2008 10:20 AM	Air barrier Should you allow for a air barrier between the foam and the substrate in your attic. Customer wants the foam sprayed directley to his roofing steel ( no air barrier ). Or should 1/2 lb foam be sprayed to attic ceiling and how much.
Gerry Wagoner Posted: Apr 16, 2008 07:52 PM	I see no problem with spraying directly to the underside of the metal roofing. We have done it many, many times. Each time has proven successful over a 24-year career span. If you use soft foam (half-pound) on the attic deck, use about 7-8" Have fun, oG
kevin smith Posted: Apr 16, 2008 09:17 PM	What if you decide to go with 2lb cc foam. how much and should there be a air barrier?
Gerry Wagoner Posted: Apr 20, 2008 09:31 AM	Closed-cell is fine up against the roof deck. This material is an air barrier, by the way (see ASTM E 2357). Depending on your location, I'd recommend 4-5". enjoy, oG
Michael Griffin Posted: May 15, 2008 02:10 PM	One of my local installers in NY is recommending spraying directly to the underside of the rooof plywood with closed cell foam and no air space. This is a very complicated roof and has lots of nooks and crannies. The roof itself is a standing seam metal roof applied direclty to the plywood. I am afraid that moisture will get between the foam and the plywood and cause mold and eventually rot. Any opinions ?
Michael Griffin Posted: May 15, 2008 02:10 PM	One of my local installers in NY is recommending spraying directly to the underside of the rooof plywood with closed cell foam and no air space. This is a very complicated roof and has lots of nooks and crannies. The roof itself is a standing seam metal roof applied direclty to the plywood. I am afraid that moisture will get between the foam and the plywood and cause mold and eventually rot. Any opinions ?
Posted: May 15, 2008 02:49 PM	Seems like as long as you have proper adhesion in the cavity (foam should stick like glue), there would not be any space for trouble to happen. Kindly, Brian www.roofcrafterswest.com
Michael Griffin Posted: May 15, 2008 07:15 PM	Thanks for the advice, the concerns are twofold : 1. If there is any opening left in the seal moisture/air will get in and like I say this is a very com-plicated roofline. 2. If the roof leaks you really will not know until the plywood is gone. It is good to know though that if done correctly, there should be no moisture penetration.

Author

Comments

kevin smith

Posted: Apr 15, 2008 10:20 AM

Air barrier

Should you allow for a air barrier between the foam and the substrate in your attic. Customer wants the foam sprayed directley to his roofing steel ( no air barrier ). Or should 1/2 lb foam be sprayed to attic ceiling and how much.

Gerry Wagoner

Posted: Apr 16, 2008 07:52 PM

I see no problem with spraying directly to the underside of the metal roofing. We have done it many, many times. Each time has proven successful over a 24-year career span.

If you use soft foam (half-pound) on the attic deck, use about 7-8"

Have fun,

oG

kevin smith

Posted: Apr 16, 2008 09:17 PM

What if you decide to go with 2lb cc foam. how much and should there be a air barrier?

Gerry Wagoner

Posted: Apr 20, 2008 09:31 AM

Closed-cell is fine up against the roof deck. This material is an air barrier, by the way (see ASTM E 2357).

Depending on your location, I'd recommend 4-5".

enjoy,

oG

Michael Griffin

Posted: May 15, 2008 02:10 PM

One of my local installers in NY is recommending spraying directly to the underside of the rooof plywood with closed cell foam and no air space. This is a very complicated roof and has lots of nooks and crannies. The roof itself is a standing seam metal roof applied direclty to the plywood. I am afraid that moisture will get between the foam and the plywood and cause mold and eventually rot. Any opinions ?

Michael Griffin

Posted: May 15, 2008 02:10 PM

Posted: May 15, 2008 02:49 PM

Seems like as long as you have proper adhesion in the cavity (foam should stick like glue), there would not be any space for trouble to happen.

Kindly,
Brian
www.roofcrafterswest.com

Michael Griffin

Posted: May 15, 2008 07:15 PM

Thanks for the advice, the concerns are twofold :
1. If there is any opening left in the seal moisture/air will get in and like I say this is a very com-plicated roofline. 2. If the roof leaks you really will not know until the plywood is gone. It is good to know though that if done correctly, there should be no moisture penetration.

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