Hi everyone,

I'm in the process of leveling a very uneven floor (for example, 2” in 8 ft, and 3/4” in 3 ft). The space is a small condo in a wood-frame building from the 1950s, and has two layers of subfloor, both fir (one diagonal ship lap, the other 3" wide boards). I’m not a professional (not even close).

So far, I've leveled by installing a patchwork of plywood: 1/4, 3/8, 1/2, 5/8 and 3/4 all screwed and glued. The problem is that various high spots needed to be sanded down which has caused a lot of noise which is a problem in a condo situation (I’m not exactly Mr. Popular at the moment).

Floor leveling compound is a tempting, no-noise solution, but there are two problems: one, what is the maximum amount of compound you can build up? What brand should I look for? I saw a reference to a concrete-based leveler (I think) and wonder if this might be suitable between two lawyers of wood.

Second, do I need to decide on my flooring before I proceed? While I'm leaning toward solid hardwood, there is a chance that I'll go with engineered, or maybe even laminate. I have read that leveling compound is not compatible with hardwood, as you can't nail the hardwood into/through the compound, and so it seems to me I need to know whether the floor will be nailed, screwed or floated.

Would really appreciate some advice on how to get myself through this one. thanks.

The question would be, is that floor structure stout enough to hold the weight of a cement pour??