• If your dirty grout just won’t get clean, it might be time to replace it instead.
• Grout should also still be in good structural shape to make cleaning worthwhile.
• Grout darkening, cracking, shrinking, or impacted by moisture should be replaced.

Dirty grout can be cleaned or recolored to revitalize its appearance. But you may eventually need to take on the more laborious task of removing and replacing the grout.

We spoke to tile and home experts to help you determine if you can keep cleaning your grout—and when to replace tile grout.

When to Keep Cleaning Grout

Tile experts and contractors say that it’s okay to continue cleaning grout if the grout is only lightly discolored, responds to deep cleaning, and is in good structural shape.

Bar Zakheim, a contractor with Better Place Design & Build, says that you should be able to clean the grout with a paste of baking soda and bleach. If a deep cleaning with this paste renews the grout’s original color, you’re good. If not, replace the grout.

“Because grout is naturally porous, over time it absorbs anything from moisture to dirt and grime,” says TileCloud interior designer Courtney Cole. This porosity makes cleaning grout particularly difficult, says Cole. 

Grout must also be in good structural shape for you to continue cleaning it rather than replacing it. Tile grout in good shape is:

• Solid: The grout is tightly bonded and is not loose, cracked, crumbling, or missing.
• Fills the seams: The seams between the tiles are completely filled with grout from side to side, with no grout shrinkage.
• Nearly flush: The grout is just below the top of the tile surface, not deeply pitted.

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When to Replace Tile Grout

It’s time to replace tile grout when the grout turns dark colors, crumbles or cracks, shrinks, or is in a high-moisture area.

Grout Is Darkening

Lightly stained tile grout can usually be cleaned. But experts indicate that certain colors and shades might be beyond cleaning.

“If your grout looks dark brown or black even after you deep clean it, it’s likely that no amount of scrubbing will bring it back to life,” Cole says.

Marin County-based interior designer Judi Cooper adds that a “sickly shade of yellow” signals the need for grout replacement. When you see that color, the grout is past saving, Cooper says.

Grout Cracking or Crumbling

More important than the grout’s color is how well it’s staying in place, Zakheim says.

“Grout that is cracking, flaking, and leaving gaps that water can enter through needs to be sealed or ideally replaced as soon as possible,” Zakheim says.

Cole agrees: “If you start noticing cracks in the grout in the kitchen or bathroom, you need to get on top of the issue right away.”

With cracks, your tile grout is past the point where cleaning will help. The only option is to dig out the old grout and replace it with fresh grout.

Grout Shrinking

Grout shrinkage is another structural problem that indicates when you should replace tile grout. Grout shrinkage is a grouting mistake that typically happens soon after installation. 

Too much water in the grout mixture causes the grout to shrink as it dries. The grout will gradually separate from the tile.

“When your grout separates from the tile, it’s already reached its failing point,” Cooper says. “Moisture seeps in, and now you’re battling mildew and loose tiles.”

The only fix at this point is to rip out the grout and start fresh. A proper regrout can be the difference between upkeep and decay, Cooper says.

Grout Affected by Moisture

Well-maintained tile grout should be able to tolerate contact with water. So, tile experts stress that moisture can make a difference only with tile that’s in poor condition.

“In areas of the home that are high in moisture, it won’t just be an aesthetic issue but one that can turn into a structural problem by seeping behind the tiles,” Cole says.

Water can enter through poor tile and needs to be sealed or ideally replaced as soon as possible, agrees Zakheim. He adds that high-moisture areas like bathrooms are especially susceptible to moisture damage.