Hello.
I am building a toilet that will be built into the wall. I have made a framed space there that needs to be waterproofed. But before I start, I need to fix the surface against the studs. Is there a good filler I can use on untreated wood, or something else I can use?
I bought carpentry filler, but the can said it should not be used on untreated wood. Can I use this if I paint the space before filling?
