I will be remodeling an old bath in a 90-100 year old house. The bath was remodeled in the early 80's I believe. It will be gutted down to the bare studs, with new wiring, plumbing, tub, toilet, vanity, window, tile floor and walls. This is where the questions start and there will be many! I have searched the forums and have gotten some ideas, and I appolgize if these are repeat questions.
#1 - I have read about waterproofing the tile backer board
in the shower with redguard which is preferred over a vapor barrier behind the backer board, my question is on the outside wall that will be insulated and a vapor barrier is needed, do you just put the standard plastic over the insulation on the area from the tub lip down, and use redguard on the backer board from this point up? I know you cant have a vapor barrier on both sides.
#2 - I have the old 1x8 diagonal floor boards on the 2x8 floor joists which I believe to be Doug Fir otherwise pine (there are no markings to see) in good shape 16" on center with 3/4" thick hardwood flooring on that plus a layer of vinyl. I will be removing down to the 1x8 and building back up from there, or should I go down to the bare floor joists and cut the 1x8's out? I will attatch a few pictures showing the underside of bathroom floor. There is an area that a plumber cut out a whole rafter and just left it when toilet was installed sometime. New plumber said he can slide it back a few inches allowing me to bolt a 2x8 alongside the old cut one from the wall to the top of the beam, which I hope will give me the strength I need. If that was a solid joist not cut, I would be in good shape for deflection, hopefully by sistering a 2x8 alongside supported by the beam I will be ok as far as deflection, but really dont know how that affects numbers, very poorly I assume. I guess my question is, what is best for this situation? I will be using 12x12 ceramic tile on the floor. The span is now 8' for the floor joists, it was 12 until I added a beam.
Hopefully this helps explain what I am trying to ask. I will have many more questions I am sure, but this is a start.
Thank You in advance!