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Originally Posted by Binger
so let me see if I understand this. The polyiso stuff would be those big sheets of that foam that is usualy put on behind siding. This is then cut into strips and laid in the rafters back into the wedge were the floor and the roof meet?
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Yes
Quote:
Originally Posted by Binger
then the cellulose goes in over the top?
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It can go over the top. In my case, this area was thin on insulation and the only way to get a decent R-value was to use pollyscio foam where they have fiber insulation in the diagram because, the pollyscio foam is R-7/inch, cellulose is half that @ R-3.5/inch. and fiberglass is R-2.3/inch. So, if your are space constrained. use the highest R-value available.
Quote:
Originally Posted by Binger
It looks like there is an air flow area from the soffit, above the roof insulation and out into the attic?
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yes, that is the air passage.
Quote:
Originally Posted by Binger
I'm learning all the time so forgive me for this, I under stand the advantages of air flow in the atic...but what does this do better than filling the entire attic with cellulosic or pink batts?
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As I mentioned, it is best to use this foam board where you are space constrained. In this tight area on the diagram, you only have 3 inches. So, what to you want there? (7*3)= R-21 or (3.5*3) = R-10.5?
R-21 right?
Once you tackle these tight areas, the rest is easy.
Also, do you yourself a favor and avoid the pink bats. they have formaldehyde in them (FEMA Trailer anyone?), they under perform cellulose, and they LOSE 20% of their R-value when the temp drops below 30 F. The stuff sucks.
Before you install the loose fill cellulose, make sure you seal up your attic, like I said earlier in this thread.
Larryrose11