I live in Vancouver, and my condo is about 25 years old. A couple of the tiles in the tub/shower surround are cracked, and I know that when I take them off I'm going to find soggy drywall. I'm committed to taking the surround down to the studs, but I'm not sure about putting it all back together. The bathroom has no outside walls, and the only fixtures are the tub/shower and the toilet. The tile is only on the tub/shower surround. Do I need a vapour barrier, or do I "just" replace the drywall in the surround with cement board and then tile over the cement board? Thanks for your help!
Yes you do need a vapor barrier. Replace the sheetrock with cement board and use Redgard waterproofer over cement board following instructions. Install tile and seal grout.