As part of the cosmetic updates for the bath, I decided to remove the moldy caulking where the tile meets the bathtub. It looks like the previous owner put the caulk over the grout, I'm assuming because it had cracked. When I stripped the caulk, I got an uneven line of old grout with varying depth and still with mold spots here and there. Looking online, the consensus seems to be that the tile edge at the bathtub needs to be caulked, not grouted, so I figured I would need to remove the old grout anyway whether I would re-grout or caulk.
I tried removing the grout with the grout saw but this was very tedious and there were also some tiles with a gap thinner than the saw. So I used Dremel with a 1/16 carbide bit to make ~3mm deep groove - this went faster - however because of the work angle in the corners I cut into the tile in some areas resulting in a gap as much as 1/8" (see the pic).
At this point I'm thinking that re-grouting is out of question since the tile edge is uneven; I could use caulk and get a straight line but wouldn't I still eventually get the mold behind the caulk?
- Would I have to clean out all old grout from the groove before caulking? The groove is ~3mm deep.
- Would sealing (with a grout sealer) whatever grout is left in the groove and caulking over it help with reducing mold growth? The shower will likely be used daily.
The rest of the grout/tile is in a good condition. What is my best course of action from here?