I'm refurbishing our bathroom. I had to tear out the old plaster/drywall because of the mastic left when I removed the old ceramic tiles on the wall. I'm ready to install drywall and plan to install the moisture-resistant kind.
Should I install some sort of vapor barrier, like poly sheet or whatever, before I put the drywall up? There was nothing like that there originally. Or is this only for outside walls?
Is there any sort of insulation--foam sheets or whatever--I can put in the wall that will help reduce sound? Would I want to put regular thermal insulation in there for this purpose, or would I need to get special sound insulation for this (none of the bathroom walls are outside walls, so there's no need to do this for thermal insulation). Should I even worry about sound dampening--the drywall seems rather thick?
Also, I'm a bit confused as to how to cut out portions of the drywall for plumbing etc. Do I want to try to cut all the necessary openings in the drywall before I nail it up or do you typically make the holes for the plumbing, electrical outlets, etc. after it's been attached to the wall? I can see advantages and disadvantages either way. Or some combination of both?