Where do I get insulation for my concrete floor?

I don’t know of any rigid insulation that you can walk on. Have you found it and have a brand name and just want to know where to buy it?

Im thinking you’ll need to furr-up the floor with treated 2x4’s “flat studded” and then fill in the sections with foam insulation sheets, and you can get a R-10 at double thick, then put 5/8” plywood on top of it and then your finished flooring.

Sweets Catalog on-line, is where architects and engineers go to find unusual building products. That’s where I’d look.

We’re talking a Live Load of 600 lbs per square foot and I don’t know of any foam sheeting products that will do that. Sorry.

I don’t know of any fiberglass embedded cementicius backer board (like Hardi board) that has been tested for an R-Factor, sorry.

There’s also insulation that comes in rigid styrofoam sheets. These can be laid on the floor. You will have to first put down vapor barrier and cover the insulation with something like laminate flooring. The sheets are cheap and easy to work with because they can be cut with a utility knife. The downside is that they have a low ‘R’ value, mostly less than R-5.

Check out this forum discussion:

https://www.houzz.com/discussions/3703006/installing-laminate-flooring-over-rigid-foam-insulation-in-basement

Like Zard said, you can put it down, but have to put some type of flooring on top. You really don't have to worry to much about the R factor since you loose most of your heat up and some on the walls. This will just make the floor warmer to walk on.