Submitted by eagleslanding t3_10jkdw2 in DIY
The caulk in my shower running along a 270 degree edge / ledge wore out and needs to be replaced. I tried running silicone caulk along the edge, and it stuck in initially but came out the first time it was cleaned. Is there anything special I should do in terms of approach or materials to successfully caulk this?
UpgrayeddSmurphy t1_j5kz5ca wrote
Typically, this isn't an edge that would necessarily need caulking. What should've been done is bring the surface tile flush to the face of (or just proud) the wall tile, so the grout edge is on the flat of the wall, instead of the corner of the transition.
Secondly, an 1/8th on an inch is minimum for a grout edge to bind well, and this looks too thin, which is likely what's giving you problems.
You should remove as much of the grout that's in there, maybe use an angle grinder with a diamond wheel, or dremmel to help widen the gap just a scotche.
Make it clean as possible, and wipe it down with something like mineral spirits. Tape the two outside edges and then caulk it with a good shower n tile caulk (dap 3.0 I like), making sure to "push" it in deep.
The alcohol will help dry it out before the caulking, cuz any water left in there is just going to fail your silicone. Also: it says 2 or 3 hour "shower ready", but I always recommend letting it cure overnight before you get it too wet.