subfloor prep

Can OSB subfloor cause problems with certain types of flooring?

Is self-leveling compound necessary for every flooring installation?

How thick should the plywood subfloor be for hardwood installation?

Our floor slopes toward one corner — is that normal settling or serious?

There's old adhesive residue stuck to the concrete — how is that removed properly?

The floors aren't level between rooms — can that be corrected before new install?

Should sagging floor joists be corrected before any new flooring goes down?

What moisture reading is too high for hardwood install?