Can we talk about the moisture content rule for hardwood over concrete?

I was reading a guide from the National Wood Flooring Association and it said the concrete slab needs to be under 75% relative humidity before you install. I found that out after a job in Tampa where we had to wait three extra days for a slab to dry. Has anyone else had to push back a schedule because of this specific number?

2 comments

2 Comments

taylor.jessica14d ago

Yeah, that 75% rule is no joke. Learned the hard way on a project in Savannah, same kind of humid mess. You skip that test and you're begging for cupping and gaps later. It's a total schedule killer, but waiting is cheaper than a callback and a full tear-out. That guide isn't just making up numbers.

finley93914d ago

Ugh, tell me about it. I rushed a job in Charleston and the boards looked like a roller coaster by October. That wait feels painful but it's nothing compared to a redo.