I am planning to insulate my walk-in attic to turn it into a storage room(closet for the wife), but I am having some issue understanding the process.
The ceiling of this attic is at 45 degree. It has a 32 inch door to it. The attic above has old insulation, but that's another project.
I live in Connecticut and I believe I am in zone 5. How do I achieve the 38 r value with only 5.5×2 ceiling trusses?
I am planing of course to put rafter vents (baffles), and then use unfaced batts and then a dry wall. But the only batts I can use is 21 r-value with thickness of 5.5 in.
EDIT: I am NOT looking to use foam in this project.
My attic looks similar to the picture here.
Best Answer
You cannot achieve R38 in only 5 1/2 inches. One of the highest rated insulations is spray foam, and it is around R6 per inch, which would require 6 3/8 inches at least. If you did fur out the rafters with 2x2s (1.5 x 1.5) then you would have 7 inches total to use and could install 1/2 inch baffles and have closed cell spray foam installed. It would be expensive, but would give you a thickness of 6.5 inches, and provide R38.