The spray can is mightier than the sword.
– Simpsons Comic #37
When I was an adolescent, I saw a picture of a bedroom from one of the Xanadu foam houses. “Look at THIS!” I said to my mother. “How would you keep it clean??” she responded. I was entranced and undeterred.
The foam spray guys visited today, so we have a temporary semi-version of my one-time dream room, soon to be covered with easily cleanable drywall.
This is closed cell urethane insulation, sprayed in place by some extremely nice guys who were sweet to the cats. This material was not in the original plan for the insulation, but the contractor gave us a bunch of options, and spray insulation gave the most bang for the buck.
- It was sprayed over rigid foam insulation put in place with spacers to allow cold air to circulate under the roof to avoid ice dams.
- The closed cells enclose gas that doesn’t conduct heat well, so it offers a lot of insulation value in a comparatively small space. That means that we will enjoy a much higher R-value without losing as much headroom.
- There may be a tax deduction for making the place more energy efficient.
- Once it cures, it’s non-toxic. I mean, don’t eat it or anything, but it won’t make you sick just being in your walls. Plus, it’s a moisture barrier so it helps keep out mold and other sick-building problems.
- Since it expands, it seals up leaks that fiberglass batts or other options cannot reach.
The downsides are that there is a fair bit of wasted material because anything that expands beyond the insulation area must be cut off and discarded. (The dumpster is now full!)
The other issue is that the material needs to be walled in (even in unused attic space) with a thermal barrier. The barrier is typically drywall or plywood; drywall will be in the livable space, of course, but the storage areas will need to be lined with plywood. That’s an added expense. Why do you need that? Apparently, the insulation might combust in a fire, so the thermal barrier keeps the insulation separate from open areas of the house. (It’s not a fire risk to use, though — read more here.)
If you choose this method, when you are having the work done, make sure you’ve cleared the space so they can get to everything and corralled your pets. Be aware that it’s going to be stinky for a short time while they are spraying. But the foam sets up very quickly, and the smell disappears. Leaking smells are probably not dangerous, but you might want to not be home, is my point.
The cats would have preferred not to be home. There are weird pumping sounds and smells, and afterwards, everything looks different.
Progress. Just a few more things, and then sheetrock. Then we need to kick in the bathroom tiling to get this thing (largely) done!