We are doing a bathroom remodel of a Florida home built in 1995. For the walls in the tub area, they used treated lumber along the concrete slab and regular 2X4 for the wall frames. We have a large tub and there are two support walls for the length of the large tub and two end 1/2 walls and then covered them with green Sheetrock and 6"X6" bath tile. When I opened it up, there is black mold on the existing lumber. I immediately sprayed it with bleach (but did not scrub it and tried not to disturb it) and will have that black mold lumber removed professionally.
My question is, once that black mold is gone, I want to go back with treated lumber for that entire area so I won't have the pest (insects Florida is known for) and mold issue again.
Can I put treated lumber into those sheet rocked (actually going back with cement board) walls? I will use galvanized nails & screws for framing & the cement board that will be attached to the treated lumber. But, I keep reading 'no' you can't use treated lumber because they have chemicals. But I think they are talking about the entire house, and I can understand that for an entire home, but for what I am going to use it for I did not know if I could or not.
What I will be building is:
- Two 2"x4" stud "1/2 walls" (56" long by 40" tall)
- Two 2"X4" stud "tub support" walls 60" long by 12" high??
Would this be safe if it is covered with cement board and new tile?
Or, is there anything I can paint on the lumber to help with these pest and mold issues for/in the future?