Spraying attic above garage | Ask Mason Knowles - SPF Consultant | Spray Foam Technical Questions and Answers | SprayFoam Magazine Q&A Forums

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john rogers Posted: Mar 14, 2015 10:14 PM	Spraying attic above garage Got a Ford engineer that wants 5" of CC on the underside of the roof deck. He also wants 5" of CC to the attic floor of the Garage. Pull down stairs to garage attic. attic also covers part of living room next to garage. I would like this job, but what pitfalls are here in this job? outside walls of garage are full of Tripolymer. (R-17) garage door is 4" insulated foam. 3 car garage with a 1969 Boss 429 Mustang. (this will be moved out prior to spray job) The inside wall to the house has R-7 insulation. Fiberglass. Some leakage to the garage of heat.
Bryan Kwater Posted: Mar 15, 2015 12:51 PM	I would recommend spraying the roof deck of the garage attic, and just spraying the attic floor in the portion that is above the house. This would make the garage and the attic an equally conditioned space. Unless there is some other reason that he wants the attic isolated. Check the ICC-ES report for the foam that you spray. Most likely if the attic is going to be used for storage, you will need to cover the foam with a 15-minute thermal barrier. Tripolymer foam in his walls? Ughhh.
john rogers Posted: Mar 15, 2015 09:38 PM	DC-315 being sprayed to all foam in the attic. He want to keep the garage as warm as possible with out a heater in the garage. The Tripolymer was installed in warm weather at the correct density with thermal imaging to verify a complete fill of every cavity. Installed properly Tripolymer works fine.
mason Posted: Mar 20, 2015 03:51 PM	was out of town and did not get to the site. sorry for the late reply Trying to visualize the floor plan of the house. Normally you isolate the garage as exterior space and spray foam to insulate it from the living space. So, spraying the floor over the living area makes sense to me. But, if that is the only part of the garage that is adjacent to the living space, I don't see a need to insulate the underside of the garage roof deck. Is the roof deck of the garage continuous to the roof deck of the living areas? If so, then definitely spray the underside of the garage roof deck. Agree that chances are the garage space would be used for storage and a thermal barrier would be needed. Particularly so if the floor is to be decked with plywood.

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john rogers

Posted: Mar 14, 2015 10:14 PM

Spraying attic above garage

Got a Ford engineer that wants 5" of CC on the underside of the roof deck.
He also wants 5" of CC to the attic floor of the Garage. Pull down stairs to garage attic. attic also covers part of living room next to garage.
I would like this job, but what pitfalls are here in this job? outside walls of garage are full of Tripolymer. (R-17) garage door is 4" insulated foam.
3 car garage with a 1969 Boss 429 Mustang. (this will be moved out prior to spray job)
The inside wall to the house has R-7 insulation. Fiberglass. Some leakage to the garage of heat.

Bryan Kwater

Posted: Mar 15, 2015 12:51 PM

I would recommend spraying the roof deck of the garage attic, and just spraying the attic floor in the portion that is above the house. This would make the garage and the attic an equally conditioned space. Unless there is some other reason that he wants the attic isolated.

Check the ICC-ES report for the foam that you spray. Most likely if the attic is going to be used for storage, you will need to cover the foam with a 15-minute thermal barrier.

Tripolymer foam in his walls? Ughhh.

john rogers

Posted: Mar 15, 2015 09:38 PM

DC-315 being sprayed to all foam in the attic.
He want to keep the garage as warm as possible with out a heater in the garage. The Tripolymer was installed in warm weather at the correct density with thermal imaging to verify a complete fill of every cavity. Installed properly Tripolymer works fine.

mason

Posted: Mar 20, 2015 03:51 PM

was out of town and did not get to the site. sorry for the late reply

Trying to visualize the floor plan of the house. Normally you isolate the garage as exterior space and spray foam to insulate it from the living space. So, spraying the floor over the living area makes sense to me.

But, if that is the only part of the garage that is adjacent to the living space, I don't see a need to insulate the underside of the garage roof deck.

Is the roof deck of the garage continuous to the roof deck of the living areas? If so, then definitely spray the underside of the garage roof deck.

Agree that chances are the garage space would be used for storage and a thermal barrier would be needed. Particularly so if the floor is to be decked with plywood.

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