I only have a couple of tiles in my shower to grout. I bought some pre-mixed tile grout from Home Depot. It says on the back NOT FOR USE IN SHOWER OR UNDERWATER. I called home depot and they said it would work if I were to seal it. As many know sealer is very expensive and I‘m only doing a couple of tiles that will be exposed to water. Do I have to seal this? I understand there exist grout with sealer already inside.....
You can get grout sealer in a small tube at Home Depot. If you don't seal these few tiles, you could be creating a larger problem for yourself down the road. Go for the expense, or risk doing damage to the backer board.
Im a floor installer and as i would probable have grount to match your grout ...You do not... so what i recomend you do is.. bring it back to home depot and get matching caulk.. yep you heard me.. their is sanded and non sanded caulk now a days to match you grout...thats what ya do and while your at it re caulk ya tub w/ whats left...lol
Sealer, sealer, sealer... It's like the magic solution for everything now. The most important thing about what you are doing is the adhesive for the tile. Make sure it can handle the water. And spread it thick... let the tile squeeze it out and wipe out the excess. You cannot have air bubbles under the tile. The steam will expand the air in that bubble (1,000 times it's cold volume) and pop the tiles. As for grouting between the joints: consider using caulk instead. You can specially order (at the hardware store) tinted and colored caulks. In a shower, there is no better solution. I bought a grout remover tool and took out the grout in my tile shower then installed a light sand colored caulk 15 years ago. I never sealed the glazed tile and it still looks good.
