Now we're demo-ing

Actually, it's less "we" more "I" as Steve has gone to Los Angeles. He said to leave it and he'd get round to it at the weekend. When I asked which weekend it turned out to be Xmas. I think I can have the walls stripped before then.
It was no wonder we had a leak. The wallboard at the bottom of the shower was completely black and rotten. Whoever replaced the shower valve didn't caulk around it and water has been dripping down there for who knows how many years. All that damage for want of five minutes and a $5 tube of caulk. Luckily, the wood behind seems sound and every other piece of board is dry so far. It doesn't really matter as we're going back to the studs and putting in cement backer board but if the wallboard is dry there is less chance that we'll have any structural problems or other nasty (expensive) surprises.