My goal is to keep hot/cool air from seeping between floors. Is canned spray foam the way to go? Any recommendations? Pest resistance is a bonus.
Buy a 3D printer to make a custom cover. 2 years later you’ll be too busy maintaining (“upgrading”) your printer that you’ll forget why you got it in the first place.
If this is the ceiling and a small room I would put a utility ceiling in. Where I live for a room like a simple washing room that would be 150 euros tops and you can always run new wires and get to the old ones without hassle. Nothing else will make it look pretty.
Expanding spray foam.
Don’t do that, there’s wires and pipes in there. If anything needs maintenance or replacing it’s a nightmare with expanding foam gluing everything together.
Just put in some steel mesh on the bottom, fill with isolation materials, lock it in with more steel mesh and put a nice cover plate over it.
You can cut it with a knife or a jab saw. It’s used in AC installation all the time.
Also a huge fire hazard, don’t do this.
Concrete in a super soaker 50
I think people are voting on the practicality of this suggestion, but I think it’s a hilarious image. I had a super soaker 30 when I was in early double-digits and it was so much fun to load stuff other than water in it.
You would want something like this. The important part is that it comes in two pieces so you can install it without having to disconnect anything to pass it through. The brushes are to resist airflow, but they are obviously not going to be airtight or pest resistant. For that, I would use expanding foam insulation. Those cables and pipes aren’t going anywhere, and if you absolutely had to replace one, removing the sprayfoam is a trivial effort compared to the rest of the job.
This feels like the best answer. Those are your air conditioner lines. You probably don’t want to seal them in with spray foam.
Your best way to keep pests out is to track those lines from your A/C unit outside to where they enter your house. Seal that up with the pest resistant foam if there is any daylight.
Shove some rockwool insulation into the hole. You can finish with steel wool too for added pest protection. Then put the cable cover up to make it look pretty.
