Hi there – been using this site for about a year. Just performed an energy retrofit where I ripped out the ceiling in the garage Redid the ducting system, fixed a lot of electrical that was wired incorrectly or unsafe, airsealed, put ithen put in two layers of 1/2″ polyisocyanurate, covered with 1/2″ drywall.

If you follow this link: https://www.greenbuildingadvisor.com/cad/detail/air-barrier-garage-band-joist-1-rigid-insulation-1×3-wood-furring

that is exactly the configuration i built to (I did not use furring strips like the detail calls out though).

assuming you can follow the link to the drawing…the wall that is shown separating the garage from the conditioned living space is my next part of the project. the previous owner punch a lot of holes in the wall to put in new wiring, etc. Previous owner didn’t even bother patching the holes because the other side of the wall is the area beneath the staircase which serves as a storage area. Leaks conditioned air like you wouldn’t believe.

So the wall butts into a block wall – the other end of the wall butts into another garage wall which separates from the unconditioned garage to the conditioned interior. I have been looking for a detail which describes how I should rebuild the wall. I plan, w/o guidance, to also add the 1″ of polyisocyanurate. Really my confusion centers around how to attach the 2×4 to the block wall. Also, so long as I’m taking the wall apart, should I re-affix the top plate with a different technique?

I’m long winded, sorry. Hopefully the question makes some sort of sense.