A lot of the work done by the previous owners of our wasn't entirely correct. We've developed some pretty serious vertical cracking in the grout along the inside corner joints in our tiled shower. For what it is worth, the tiles are just simple 1" square ceramic tiles and we don't really have cracking anywhere else. The major crack is in the corner behind the shower head, so it doesn't get hit by the water directly.
From what I have read, it seems as though they should have used caulk rather than grout. So, what do I need to do here? I am sure I need to remove the existing grout and then caulk the joint, but I am not sure how best to handle it. This is our only shower and my understanding is that caulk needs to be applied to a perfectly dry surface and then allowed to dry, but we don't have that luxury. Is there a special type of caulk I can use that works better with wet surfaces and/or dries quickly? Has anyone had any luck taping plastic over an area like this? Other thoughts? Suggestions?
We will be remodeling the entire bathroom in 2-3 years (after we add an additional bathroom this coming year), so the solution doesn't need to last 15 years.