danboston

I am remodeling my basement and want to insulate the concrete floor. I have about 2.5" of headroom that I can steal for insulating the floor. What si the best method for insulating the floor?

joecaption

I use blue foam insulation with Advantec over that, Tap Coned to the slab with 3" long screws. Worked great and there's 0 movement of the subflooring.

danboston

Great, I checked out the Advantek web-site. It looks good. I do plan to put in a bathrrom in the basement and wanted to tile over the insulated floor. Somone else said I should use Ditra board over the foam board insulation. Should I put the Advantek down first and then the Ditra board over that?

carolinacustomkb

I would probably subfloor the entire basement. If the subfloor is sound and you don't need waterproofing, then you don't need Ditra...you would use a backer of your choice. Thin set it down and screw it to the subfloor.

Installing plywood over the entire floor will also eliminate any floor height differences. 1/4" backer with a 5/16" thick tile should flush out really well.

Perry525

If you are using floor grade Styrofoam, you should go for a fully floating floor. If you use metal screws, each screw provides a heat bridge to pass your heat to the concrete slab, nullifying the point of insulating.
A fully floating tongued and grooved waterproof plywood floor is best.
Is your floor always dry? What about the walls? Are they dry?