Dear James: The grout on the bathroom tiles is crumbling and looks dark even after using bleach. I don’t want to remove the tile and redo it. Can I just replace the grout myself?
— Damon W.
Dear Damon: You probably won’t have to remove any tiles in the discolored grout areas. Where the grout is crumbling, water may have gotten behind the tiles and loosened them and damaged the wallboard. Carefully pry on those tiles and remove any that are loose. Examine the wallboard for deterioration.
When there are just a few loose tiles and the wallboard is good, you can stick them to the wall again. Don’t just regrout them and think this will keep them in place. After you have taken care of any unruly tiles, you must remove all of the old grout. This is the most difficult job in the whole project. Unfortunately, you cannot just add more new grout over the old bad spots.
Today there are many tools available at home center stores to help make this part a little easier. There are even electric tools that can speed the process along, but if you use one, be careful. These can sometime be difficult to hold on to and can cause damage to your tiles.
If you are nervous about handling a power tool, you can also just use a utility knife, chisel and hammer, or an awl for narrow areas. Make sure you also remove all of the caulk out of the tub’s corners.
Some people’s skin can become irritated from the grout and often pieces will fly once you have loosened them. To protect yourself, wear rubber gloves and safety goggles. To protect your bathtub, lay down a drop cloth to keep it from getting scratches.
Start removing the grout at the most unattractive point. The section that is already falling apart will be your best option. Try to be very careful until about a one-inch section has been removed.
Once this spot is open, you can be a little more aggressive when removing the grout. To remove the next spot, chisel in the direction of the last removed area. Continue to work away from the cleared area so the old grout will crumble out.
Once this hard part is completed, you can mix and apply the new grout. Smear the grout in small areas (a few square feet) using a sponge-faced float or a squeegee. You will want to use a circular motion when applying the grout and take care not to spread it into the corners at the tile/tub seam. Wipe off the freshly grouted area with a damp rag or sponge until the tiles are clean.
Finally, apply caulk to seal the seam at the tub, joint corners and wherever the tile meets a different material. If you don’t to want watch all of your hard work go down the drain, make sure you allow the new grout and caulk enough drying time.
— James Dulley is a mechanical engineer, an avid Do-It-Yourselfer and a nationally syndicated columnist with Creators.com. Email your questions to him at Here’s How. Click here for previous columns. The opinions expressed are his own.