What’s the best subfloor under nailed-down hardwood? IAQ concerns.
Dear Esteemed Experts,
We’re about to remove and replace a hardwood floor that had severe moisture damage. There is no mold. We want to use solid hickory (WD Stang Lund), nailed down over a concrete slab. I want to make sure that we’re using a safe product that’s not going to offgas into our home.
I read in “Prescriptions for a Healthy House” ( that interior grade plywood should never be used as an underlayment. Exterior plywood is recommended instead. I presume that this is because the phenolic formaldehyde is less volatile than the urea formaldehyde used in interior plywood. Columbia Purebond is an interior NAUF plywood, but they specifically advise against using it as a structural material.
So, help! I need to know what we can use as a subfloor that’s not going to leak a bunch of formaldehyde and other VOCs into our airspace.