Insulating rim joists
We need to air seal and insulate our Rim Joists. I am in Zone 4A.
House is 100 yrs old, foundation wall is stone, and approx 12” deep. Certain joist bays are not accessible without drilling through other joists at the end of the foundation wall, to spray into the cavity.
I have been removing old brick fireblock, to access the cavities.
Reading GBA, BuildingScience.com, 475 etc, has made me wary of spray foam like reading webmd makes me think I have cancer.
I am looking to get comfortable with this process.
I have a quote for approximately $1000 for approximately 5 inches of closed cell HFO foam, from ab insulation contractor. He is licensed in my county and carries a 1 million dollar insurance policy. His crew has been spraying for about 8 years. He claims he has never had a legitimate issue with the curing process or off gassing for year, except in one instance where he did a roof, and the client refused to remove the fiberglass on the floor. After a core sample from both the manufacturer and a 3rd party they agreed the samples cured properly. He said the client ended up having the foam removed instead of removing the fiberglass.
I have talked to many of these foam contractors, this guy is the most responsive and reasonable as was recommended to me from a passive house builder I know. (Since he also dense packs etc).
Contractor said most of the issues in spraying (aside from not letting the foam cure) arise when barrels of the A and B products are replaced, and our joists are so small an area that we won’t even use close to a full barrel.
I guess you see so many failures on the internet it’s hard to belief there aren’t more failures and these bad examples are examples where, really it wasn’t the contractor fault.
Any advice to get over my angst here?
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