We ended up going with Foam insulation in the open areas. The cost was quite a bit cheaper than what we could get for the net-and-blow cellulose. I think as the job gets larger the cellulose gets cheaper but for this job, the foam was less than half the estimates we got for the cellulose We had open cell foam sprayed in the closet/laundry, the exterior wall of the master bath, and the rear wall of the 3rd floor bath. We didn’t have anything in the eves done. We are still trying to figure out just how to do the roof.
A quick lesson on foam after the jump
There are 2 types of foam, open cell and closed cell. Closed cell foam is like great-stuff. It is rigid and impenetrable to water. It is lots of little bubbles of plastic bonded together. Open cell foam is squishy like a sponge. The bubbles are what give it fluff as apposed to closed cell foam where the bubbles are the actual structure of the foam. Open cell foam is about half the cost of the closed cell and less than half as insulating.
We had open cell foam done everywhere except the kitchen ceiling. You can imagine that open cell foam is a sponge that can soak and hold water. When that is up against the roof, there is danger of rot. To mediate that risk, one common practice is to do 2 inches of closed cell foam covered in 8 inches of open cell. The closed cell acts as a moisture barrier to protect the under-side of the roof.
On the second floor:
After the spray the foam, they use a cutter to smooth it out.
In the basement, we had the tops of the basement walls foamed up. I’m hoping this will really help the frigid basement situation. It is cold down there! Tuesday was rather warm and rainy so it was hard to tell just how much warmer the basement was. We are slated to get even more snow this coming weekend so I guess we’ll find out then. Luckily the rain and warmth Tuesday and Wednesday has done a good job melting the snowbanks.
When we got home at 6:30 or so it smelled pretty bad. The off-gassing of the foam is significant. We went out to dinner which was a good call given the smell. By the following morning either we were used to it or it was quite a bit better. The kitchen smelled the worst and that is the only place they used the closed cell foam so it’s possible it smells more.
And that’s the insulation situation at the ‘ol house.
Here’s to warmer nights!