Concrete – Leveling two different floor types

concreteflooringtile

We would like to expand our kitchen into a family room, but the floors are not even, nor are they of the same material. We want to remove part of the wall between the rooms and install tile in both. The wall is not load-bearing, so that is not a problem.
The floor in the family room is concrete with carpet, and is sunk 1-1/2" below the kitchen, which is vinyl over a crawl space. The house was built in the 1920s.

What would be the best way to raise the concrete floor? I have thought about concrete overlay, or using pressure-treated furring strips and tongue-and-groove sub-floor.

The family room was originally the back porch of the house, which was enclosed quite a while ago.

Best Answer

Basically you have to bring the level of the concrete up 1½". 1½" happens to be the thickness of 2× dimensional lumber, so you could take some 2×12's, lay that on top of the concrete, and you'd be at the extant kitchen floor level. 2 layers of ¾" T&G subfloor should serve the same purpose, but, since ¾" plywood isn't actually ¾" thick, you'd likely need to buy ¼" luan or underlayment to make the levels match. Ordinarily luan is bad for tiling, but since you'll be using floor leveler you can probably get away with it.

Once that's done, remove the vinyl from the kitchen, then use floor leveling compound on the whole space. Once that dries you should have a nice level floor ready for tiling