On Jun 14, 4:08 pm, handsome greg wrote:
I've got a portion of a roof built with 2x4 rafters. I'm trying to
stuff R30 in the space with some airspace-savers underneath, which
would normally warrant 2x10's instead. What would be the best way to
build these 2x4's out to the depth I need for my insulation? Running
2x10's next to the 2x4's would be annoying, but is the only answer I
can come up with. Any suggestions? Any possibility of getting away
with 2x6's attached to the face of the 2x4's? Thanks for the advice!


I don't understand why you need to add wood to add insulation. The
insulation doesn't have to be between anything. Just put 3.5-inch
insulation between the rafters, then run more across (assuming you are
using roll fiberglass) over the rafters, holding it in place with
lightweight wire or some such. I also wonder if you mean rafters or
joists. -- H