Dear Julie
The simple test for finish adhesion, is to wait until the finish has fully cured. In the case of water based this will be 2-4 weeks. Choose a inconspicuous area, or an area that you suspect is de-laminating. Cross hatch (the tic-tac-toe pattern) a small 4 square inch area with a razor blade. Cut right down to the wood. Apply duct tape to the test and rip it off. If some finish comes off, but most remains, you are probably OK. But if it most or all comes off the floor will need to be sanded again. More coats on top of this won't help.
There is a tendency now to apply fast dry oil based finished before the water based finish. This is to avoid the grain rising on the first coat of water based. This is a fairly new development, and it may not work in all cases. Generally speaking you don't have to wait the full 30 days between coats, but in most cased 24-48 hours should be sufficient. And of course the sealer needs to be scuff sanded (screened).
Some of the more prominent water based finish companies are offering this, and if he is using say, Bona Kemi's products, and following their directions to the letter. You and he may have a claim against this company for misleading instructions. They will supply at least replacement material.
But on the other hand if your contractor used different makers of finish, they may well not be compatible, and re-sanding will be the only option. I personally stick to the same type of finish for all coats, it makes for easier touch-ups and re-coats later.
As always your Most humble servant, Joseph, the Wood Floor Doctor.
