Can You Patch a Hairline Crack in Grout?

Crack Causes

• Cracks in grout become more common over time. The more the grout solidifies and loses its moisture, the more susceptible it will be to cracking. As tiles, floors and counters shift over time, and the grout does not shift with them; thus, small cracks can appear, especially between the tile and the grout. Extreme temperature changes can also produce this effect.

Removing Grout

• While you can patch hairline cracks in grout, you must be prepared to remove the entire section of grout. Simply putting new grout over the crack will not solve the problem and will cause your grout to look uneven. There are grout saws and power saws designed to remove grout in this way. If your grout is crumbling, then you may be able to chip away the top layer and leave some of the bottom layer of grout.

Sealing Grout

• Once you have covered the removed section of grout up with new grout and let it dry, you must reseal the grout section. This is a very important step, because one of the primary dangers with hairline cracks in grout is the possibility of water leaking down and damaging the floor. The new layer of sealant will protect the grout from moisture and any further damage.

Considerations

• When you patch a grout crack, you may want to test the grout in a small area first to see what color it dries to. Grout colors can be difficult to match, especially when mixing aged and new grout. You should also clean all surrounding tiles after you apply the grout but before it dries, in order to remove the "haze" that wet grout will leave on tiles unless it is thoroughly cleaned off.