Previous owner said they always had huge icicles off the back of the house. This would be why.

.75 inches of fiberglass, where there should be at LEAST 8 inches, and code for our area more like 15 inches.

Combine that with the uninsulated, unblocked floor cavities in the upstairs floor joists, that lead directly to the uninsulated attic space...

And combine THAT with the 4(!!!) access points to the attic that were not only completely uninsulated, but also had no weather sealing, and ⅛-¼ inch gaps around all edges.

This house was literally leaking warm air like a sieve, all winter long.

I'm only putting in 8 inches of fiberglass batting. And sealing every crack and joint I can find, as well as the gaping holes 🤦‍♂️

It'll still be under code, but, insulating it properly with spray foam would cost literally SIXTEEN TIMES MORE than just using the batting. And considering that our long term goal is to condition the attic space by insulating the roof deck, obsoleting the insulation I'm putting in now, I'm not eager to overspend.

I'll settle for only blocking 95% of heat flow, instead of 99.

Edit, update: I took a few days off, the temp outside went up, and it was sunny, so the attic got real hot real fast. No thanks, I'm not in that kind of rush.

But I got all of one side done yesterday, still need to put the boards back down, and insulate the gappy door, but it's sealed.