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.
Had almost this identical insulation situation when I bought my house. The ceiling just had some thin rock wool. First I went to Lowes and got a few cans of fire-rated spray foam and used it to seal around all ceiling fixtures, canister lights, wire penetrations, anything air can leak from. Next I built a little dam with scrap wood around the access hatch. Then spent one Saturday with a friend blowing insulation in. 8 hours of blower rental was free for every 3 bags of insulation you bought, but it didn’t take nearly that much time. Had it up to R-48 depth in only about 4 hours of blowing. I submit the receipts to my state’s energy rebate program and was 100% reimbursed. I think the blow-in did a much better job and was easier to get into odd shaped framing than bat would have been.
My winter gas bill halved, much better than I hoped. I also wasn’t expecting for my summer AC to bill drop by almost 75%. My house was MUCH more comfortable too. Almost all the draftiness disappeared after that.
I paid $0 after rebates, spent probably 12 hours labor total, and save easily $100-$200 a month.