I would just like to know how to go about fixing 2 short grout cracks on my shower floor. They are about 0.1cm thick and about 2.5 and 4 cm in length, right next to the floor tiles. What do I need to buy and can I simply put new grout on top of them or do I need to rip them out, then apply the new stuff?

Thanks in advance.

Remove the damaged grout and replace it with new. A small area like this usually means there is no problem under the tile

If these cracked areas are where the tiled floor meets the walls or the curb, that should be caulked only and not caulked over grout... just an fyi.

If these cracked areas are where the tiled floor meets the walls or the curb, that should be caulked only and not caulked over grout...just an fyi.

No, they are just between floor tiles. Can I simply put grout over the crack or put caulking tape over it?

Nope, remove the grout to a depth of 1/8" or 2/3 the depth of the tile, whichever is greater for the new grout to have enough tooth to grab and adhere. Wondering why grout would come out, though. How old is this install?

Nope, remove the grout to a depth of 1/8" or 2/3 the depth of the tile, whichever is greater for the new grout to have enough tooth to grab and adhere. Wondering why grout would come out, though. How old is this install?

About 11 years. I have just spotted the cracks few days ago, as I was doing some caulking work.

Do I use sanded or unsanded grout. The bags says they are corrosive. Will that grout eat things away (skin)?

Unsanded and yes wear gloves.