As a corollary to my other question on insulating existing walls, I am also interested in insulating my floors. Right now, only about half of the 300 sq. ft. has its "final" flooring completed. We installed tongue-and-groove laminate over a light foam underlayment on top of the existing subfloor. Unfortunately, the floor is pretty cold. It's probably close to ambient + 10°F. Because we got a ridiculous quote on a mini-split, we plan to install either electric or hydronic (above subfloor) radiant heating, and I'd like to minimize heat loss to the crawlspace.
Things to know:
- There is currently no insulation at all, other than the underlayment we added (and that's not very insulative)
- The crawlspace is about 6" deep, making access nearly impossible
- The subfloor is made of 1x2 (actual dimension, this is old construction) planks, nailed into the floor joists
- I don't want to add too much on top of the existing subfloor because a hydronic radiant system will add ~1" to the floors already
I'm willing to consider ripping up the current floor, installing rigid insulation between joists, installing a new subfloor with radiant channels already underneath, etc. but I would really rather see if there is a better way.
EDIT: I just asked another question about radiant ceilings instead of floors, so I can also consider insulation above my subfloor, provided it doesn't add more than 1-2" maximum.