Can anyone advise me on the issues I need to address with installing a hardwood floor over a gypcrete subfloor with radiant hot water heating in it?
I assume you cannot nail it, but if you glue it, won’t that conflict with the wood’s need to expand and contract with seasonal changes?
Assuming my variables are #1, Hardwood finish floor, #2 gypcrete subfloor and #3 radiant heating tubes in the gypcrete, is this equation possible to solve? Or do I have to remove one of the variables in order to finish.
The only variable that is likely to go is the gypcrete, but it would have to be replaced with a floor that 100% absolutely won’t “give,” squeak, or flex. Could it be solved by doubling the standard plywood subfloor, screwing everything down to avoid the squeaks caused by shifting, and then nailing the finish floor pretty darn carefully to avoid the tubes? That’s all I can come up with?
Gracias,
Bob M
Replies
Bob, We did this on a house last year. We started with a standard plywood subfloor then added 2x2 sleepers. The radiant tubing was looped around the sleepers. Then the gypcrete was poured to the height of the sleepers. On top of that we glued and nailed down another layer of 3/4" plywood. The hard wood nailed onto the ply. The house was an engineer's personal house, which could or could not mean anything depending on how you value an engineer's opinion. Regardless, it worked out just fine....just be careful when you're nailing down the second layer of ply.
Good luck....
Some other options. If you're willing to limit your flooring options, you can glue down. I did bamboo this way, and it's thus far working great. (The process sucks though, because the surface of gypcrete makes spreading the glue tricky.) Or you can float a floor, too.