What is a roof deck? | Ask Mason Knowles - SPF Consultant | Spray Foam Technical Questions and Answers | SprayFoam Magazine Q&A Forums

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Posted: Jul 12, 2009 08:59 AM	What is a roof deck? Excuse my ignorance but I can't seem to get my head wrapped around what the hell your talking about when we use the term "roof deck" Were I come from most of the houses are built with 8 foot walls with ceiling joists attached to the top of them and drywall attached to the under side of this. And this is were the insulation is applied above the drywall. You then have trusses or rafters above the ceiling usually at a 4:12 pitch with 3/8 sheathing and shingles on top of them and the space between the joists and trusses now becomes the attic. The attic is usually ventilated around the perimeter of the sofet or vented on the gable ends. So when you are saying to spray the roof deck are we talking about spraying between the roof trusses or the ceiling joists?
mason Posted: Jul 12, 2009 09:08 PM	In an unvented attic, the foam is sprayed to the underside of the roof sheathing (between the rafters. In a vented attic the foam is sprayed to the floor of the attic (over the drywal ceiling).
Posted: Jul 13, 2009 02:15 AM	,,it is the undersurface of the structures roof sheating,,,whether that material be wood,,metal,,concrete or other,,,
Posted: Jul 13, 2009 06:54 AM	Thank you for that explanation you guys, and my apologies for the way I blurted that question out. I was frustrated trying to understand why you would spray foam in some of these areas. As you know I am in the commercial end of the spray foam business and am not really interested in getting into the residential side of things, but I would like to remove the old zonalite in the one part of my attic and spray in some 2# BASF that I use. I would need to travel 4 hours and spend the $300.00 or so for the residential course, but I don't plan on doing any more of it.
Edward Brassington Posted: Jul 13, 2009 09:10 PM	Make sure you have the zonolite or vermiculite tested for asbestos before you remove it. If it does have asbestos get some proper guidance before disturbing it.

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Comments

Posted: Jul 12, 2009 08:59 AM

What is a roof deck?

Excuse my ignorance but I can't seem to get my head wrapped around what the hell your talking about when we use the term "roof deck"
Were I come from most of the houses are built with 8 foot walls with ceiling joists attached to the top of them and drywall attached to the under side of this. And this is were the insulation is applied above the drywall.
You then have trusses or rafters above the ceiling usually at a 4:12 pitch with 3/8 sheathing and shingles on top of them and the space between the joists and trusses now becomes the attic.
The attic is usually ventilated around the perimeter of the sofet or vented on the gable ends.
So when you are saying to spray the roof deck are we talking about spraying between the roof trusses or the ceiling joists?

mason

Posted: Jul 12, 2009 09:08 PM

In an unvented attic, the foam is sprayed to the underside of the roof sheathing (between the rafters. In a vented attic the foam is sprayed to the floor of the attic (over the drywal ceiling).

Posted: Jul 13, 2009 02:15 AM

,,it is the undersurface of the structures roof sheating,,,whether that material be wood,,metal,,concrete or other,,,

Posted: Jul 13, 2009 06:54 AM

Thank you for that explanation you guys, and my apologies for the way I blurted that question out. I was frustrated trying to understand why you would spray foam in some of these areas.
As you know I am in the commercial end of the spray foam business and am not really interested in getting into the residential side of things, but I would like to remove the old zonalite in the one part of my attic and spray in some 2# BASF that I use.
I would need to travel 4 hours and spend the $300.00 or so for the residential course, but I don't plan on doing any more of it.

Edward Brassington

Posted: Jul 13, 2009 09:10 PM

Make sure you have the zonolite or vermiculite tested for asbestos before you remove it. If it does have asbestos get some proper guidance before disturbing it.

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