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michael bergin Posted: Nov 05, 2006 01:20 AM	1.2 pound foam
michael bergin Posted: Nov 05, 2006 01:22 AM	Would appreciate some feedback in respect to 1.2 pound foam over .5 pound foam. Does the extra cost of 1.2 pound foam compensate for the less wastage of product with foam not expanding past a 3.5 inch stud. Also the cost associated with the extra time with trimming back, clean up and cost of disposal make it more viable. Or is it still more economical to use .5 pound foam.
Gerry Wagoner Posted: Nov 05, 2006 01:27 PM	Depends on the application. We like half-pound for hot roofs and spraying against the underside of a metal deck. The extra expansion helps fill & seal the deck flutes. 1.2 pound is a viable option if the R-value is around 5 per inch. The yield should be around 7500 + in order to make it an advantage. Less trimming is nice. Most 1.2's have trouble with cold cracking on studs in winter time. Maybe there are some refined blends out there that have overcome this problem. Try them and find out. Rigid is always a good product. We use a 1.6 pound rigid that yields well. Cathedrals: half-pound if the rafters are deep enough to accomodate 7". If not (and it is warm) try the 1.2. Earlier this year I took a spreadsheet and calculated the cost per "R" for many different kind of foams. This will reveal economic aspects of different foams and could be useful for price comparision. You could make one as well. Have fun and keep the trigger pulled. olger

Author

Comments

michael bergin

Posted: Nov 05, 2006 01:20 AM

1.2 pound foam

michael bergin

Posted: Nov 05, 2006 01:22 AM

Would appreciate some feedback in respect to 1.2 pound foam over .5 pound foam.
Does the extra cost of 1.2 pound foam compensate for the less wastage of product with foam not expanding past a 3.5 inch stud. Also the cost associated with the extra time with trimming back, clean up and cost of disposal make it more viable. Or is it still more economical to use .5 pound foam.

Gerry Wagoner

Posted: Nov 05, 2006 01:27 PM

Depends on the application.

We like half-pound for hot roofs and spraying against the underside of a metal deck. The extra expansion helps fill & seal the deck flutes.

1.2 pound is a viable option if the R-value is around 5 per inch. The yield should be around 7500 + in order to make it an advantage. Less trimming is nice. Most 1.2's have trouble with cold cracking on studs in winter time. Maybe there are some refined blends out there that have overcome this problem. Try them and find out.

Rigid is always a good product. We use a 1.6 pound rigid that yields well.

Cathedrals: half-pound if the rafters are deep enough to accomodate 7". If not (and it is warm) try the 1.2.

Earlier this year I took a spreadsheet and calculated the cost per "R" for many different kind of foams. This will reveal economic aspects of different foams and could be useful for price comparision. You could make one as well.

Have fun and keep the trigger pulled.

olger

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