LESLIE: Dave in Alaska, you’ve got The Money Pit. How can we help you today?
DAVE: I’ve got a multi-family unit that I own and I’m having trouble with the floor. The second and third floor, the floor is – it’s cement poured over – I think it’s plywood underneath it. But right inside the door, there’s a large area that’s completely shattered. And it dips down in sections, maybe as much as an inch, when you step on it. I’m just wondering how to repair this. Would I need to remove the whole floor?
TOM: What I think you’re describing is the fire retardant that is used in multi-family construction. So to repair this, what you need to do is to remove that surface that looks like concrete. I don’t believe it’s actually concrete; I believe it’s a product called Gyp-Crete – G-y-p-C-r-e-t-e. It basically goes on as a liquid and then it dries. And it looks like concrete but it’s really a fire retardant.
So you would tear out the old material. You’d repair the floor, which is obviously water-damaged being near a door. And then you would restore it with new Gyp-Crete to fill that area in. And if you do it in that order, you won’t disturb the fire retardancy of the floor construction but you’ll get the solidity back that you’re losing because of the rot.
DAVE: And the Gyp-Crete would be the same thickness? Because it’s almost 2 inches thick.
TOM: Yeah, you actually mix it up and you trowel it on.
TOM: So you’d mix it to fit.
DAVE: You say I’d have to repair the subfloor underneath it. So remove the plywood, go back to the joists and lay new plywood. OK.
TOM: Exactly. Yep. That would be a standard carpentry repair there. But you’re adding new Gyp-Crete on top of it to restore the fire protection.
DAVE: OK. Excellent. That’s what I’ll have to do.