[christib]

I have a few cracks in the grout in my shower. Do I have to get the old grout out between tile before grouting, or can I just grout over the existing?

[Perito]

I have a few cracks in the grout in my shower. Do I have to get the old grout out between tile before grouting, or can I just grout over the existing?

You can buy a "grout saw", either a hand saw or a version that is under power, to remove most of the grout. This is a tedious job so be patient! You might not be able to get very deep, because tiles in showers are sometimes placed very close together. I like to take a razor blade to try to scratch out as much as I can.

Also, be careful not to scratch the tile. A power grout saw is obviously more likely to scratch the tile than a hand grout saw.

Once the grout is out, make sure everything is very clean. In fact, it should probably be cleaned before sawing out the grout. They have "sanded" and "unsanded" grout in my area. Basically, unsanded grout is for small gaps and unsanded grout is for larger gaps. I also recommend adding materials to strengthen the grout and to kill mold, mildew, and fungus. The shower stays clean a lot longer if you do this.

Maybe others have more ideas about degrouting than I do.

[Bljack]

It depends where this grout is cracking. Cracking where walls meet each other or where walls meet the tub is to be expected as those are areas where movement will occur and those areas should only ever be caulked. If your grout is coming out of other areas within the tile field, there's a good chance your surround has reached the end of it's life span. Where the grout is coming out, are any tiles loose?

Decades of improper cleaners used on grout in mud wall surrounds can cause the grout to come out while the tile stays bonded but old green board walls will need to be redone.

So, whatcha got?