Hi,

Have a concrete slab with radiant heating and plan to finish with wood flooring. Having some trouble deciding on the best subfloor material–any advice would be appreciated.

Here’s our considerations:

1. Concerned about formaldehyde resins offgassing–particularly since the subfloor will be heated. I realize Phenolic resins offgas much less than Urea, but would rather avoid the problem altogether.

2. Wood sleepers seem like a good option, but how will the air space between the finish floor and the concrete affect the heat transfer? Seems like it might be less effective/efficient.

3. Ideal solution would be a t&g panel material without any formaldehyde at all. Does such a thing exist that would be practical for a subfloor? Homasote makes subflooring, but not in 3/4″ (our house is set up for the finish floor to be 1 1/2″ above the concrete).

any suggestions?

Thanks,

Ed