We had someone tell us they can install solid hardwood over gypcrete without removing the gypcrete. They said they use a "paper" type liner on top of the gypcrete, then nail a plywood subfloor in, then install the solid hardwood over that. Is this possible? To install solid hardwood in this manner??

This is the first time we've heard of this with gypcrete? All others have told us we'd need to do a floating floor or remove the gypcrete if we wanted solid hardwood.

Thanks!

I'm a remove or a floating, guy.

Thanks....can you comment on why you prefer to remove or float? is the method of wood on top of gypcrete even possible? ...just trying to understand the advantages/disadvantages of this method they've described.

Thanks!

You say they want to nail into the gypcrete? It is my understanding that gypcrete does not hold fasteners very well. So what you'd end up with is a partially floating subfloor where the fasteners failed.

The scheme I've seen involves screwing plywood down over the gypcrete. You use screws long enough to go into the subfloor below the gypcrete. Then you staple or nail down your floor. It does retain the firebreak though it does nothing for noise.

Theoretically, it will work. Flatten the gypcrete before the plywood is installed, with a product compatible with gypcrete. Don't use a portland based floor patching compound. Use something like Ardex GS-4