I had to remove some of my bathtub tile, as water had seeped behind the tile
and soaked the plaster underneath. I removed the soaked plaster (oatmeal
consistency) and dried out the wood lath.
The original tile job is poor (1950's homeowner job), but it will be six
months to a year before I can get around to replacing it. What can I use to
temporarily patch the bare area? it's about 2' x 2', with wood lath exposed.
The patch would need to be waterproof, and hopefully look better than the
spray-foam I used for an "emergency" repair.