Roofing Foam Compressive Strength | Ask Mason Knowles - SPF Consultant | Spray Foam Technical Questions and Answers | SprayFoam Magazine Q&A Forums

Q&A Forums

Roofing Foam Compressive Strength Post New Topic | Post Reply

Author	Comments
Posted: Jul 06, 2011 11:39 PM	Roofing Foam Compressive Strength Hey Mason Hope all is well! I have an unusual request that requires me to spray 2" of closed cell foam to a metal roof deck. Once this is done, the contractor will be mechanically fastening Densdeck prime over the foam and then putting on a mod bit roof over the top of the roofing board. Since there will be a 1/2" roofing board over the foam, do you think that I still need to go with 2.8 to 3.0 foam or could I go with a 2 Pound foam? Steve
swfoam Posted: Jul 07, 2011 12:08 AM	Bayouboy, Why is the contractor going to put down Densdeck and then put another roofing system on top of it? Why not spray 2" or 3" of 3# roofing foam and then coat it with silicone or better yet with polyurea. That way you will have a insulation and a roofing system that will last 2 or 3 times as long as a Bit roof? I would think by the time you put down Densdeck and another roofing system on top of it, it would be cheaper to put a foam roof and polyurea top coat on it. Just my opinion. SW Foam
Posted: Jul 07, 2011 12:49 AM	Spec job! It us fairly common to adhere polyiso to the deck And mechanically fasten down densdeck followed by a base Sheer and 2 ply with a modified granulated cap sheet. In high traffic areas it is almost protocol They are replacing polyiso with foam. Once the spec is written, there is no changing an Architects mind!
mason Posted: Jul 07, 2011 07:45 AM	You should be able to use a 2lb density foam under the circumstances you describe. However, you might have to do some trimming to get the surface profile smooth enough for the board.
Dennis Davidson Posted: Jul 08, 2011 08:18 AM	Hi Steve Glad to see your still taking on those unusual projects. How do you plan on making the metal deck level enough for the Densdeck boards?
Posted: Jul 08, 2011 08:43 AM	I'm good!!! No, I really didn't get that far. They hired a newby cheaper who sprays walls. This will be interesting to see what happens.

Author

Comments

Posted: Jul 06, 2011 11:39 PM

Roofing Foam Compressive Strength

Hey Mason

Hope all is well! I have an unusual request that requires me to spray 2" of closed cell foam to a metal roof deck. Once this is done, the contractor will be mechanically fastening Densdeck prime over the foam and then putting on a mod bit roof over the top of the roofing board.

Since there will be a 1/2" roofing board over the foam, do you think that I still need to go with 2.8 to 3.0 foam or could I go with a 2 Pound foam?

Steve

swfoam

Posted: Jul 07, 2011 12:08 AM

Bayouboy,

Why is the contractor going to put down Densdeck and then put another roofing system on top of it?

Why not spray 2" or 3" of 3# roofing foam and then coat it with silicone or better yet with polyurea. That way you will have a insulation and a roofing system that will last 2 or 3 times as long as a Bit roof?

I would think by the time you put down Densdeck and another roofing system on top of it, it would be cheaper to put a foam roof and polyurea top coat on it.

Just my opinion.

SW Foam

Posted: Jul 07, 2011 12:49 AM

Spec job! It us fairly common to adhere polyiso to the deck
And mechanically fasten down densdeck followed by a base
Sheer and 2 ply with a modified granulated cap sheet. In high traffic areas it is almost protocol

They are replacing polyiso with foam. Once the spec is written, there is no changing an Architects mind!

mason

Posted: Jul 07, 2011 07:45 AM

You should be able to use a 2lb density foam under the circumstances you describe. However, you might have to do some trimming to get the surface profile smooth enough for the board.

Dennis Davidson

Posted: Jul 08, 2011 08:18 AM

Hi Steve

Glad to see your still taking on those unusual projects.
How do you plan on making the metal deck level enough for the Densdeck boards?

Posted: Jul 08, 2011 08:43 AM

I'm good!!!

No, I really didn't get that far. They hired a newby cheaper who sprays walls. This will be interesting to see what happens.

You need to login to reply to this topic. Please click here to login.