· by Michael Blair, Nashville's Tile and Stone
Discolored grout makes a sound bathroom look finished. Replacing it is inexpensive and effective, provided the tile and the waterproofing beneath are actually intact.
When regrouting works
Tiles firmly bonded, no hollow sounds when tapped, no movement, and no evidence of water getting behind. Discoloration, staining and surface crumbling of grout alone are all fixable.
The result is dramatic for the cost, particularly in a shower.
When it does not
Hollow-sounding or loose tiles, grout that keeps failing in the same place, damp or soft board behind the tile, or a shower that has been leaking.
Regrouting over a failing waterproofing layer seals in a problem that is already causing damage behind.
- Tap every tile — hollow means debonded
- Check for soft board at the base of a shower wall
- Recurring failure in one area means water behind
- Corners get silicone, not grout, on the way back
- Color-matched grout rarely matches exactly
How it is done
Rake out to a consistent depth with a grout removal tool, clean thoroughly, then regrout and finish. The raking is most of the work and it is where tile edges get chipped by the impatient.
Take the opportunity to replace corner joints with silicone rather than grout while you are there.
Color
Matching existing grout exactly is difficult, since the original has aged. Regrouting a whole wall or floor gives a better result than patching a section.
Deliberately changing the color is often the better decision, since a slightly different match reads as a repair.