Does Grout Go Bad?

Terri Williams

Grout is a valuable yet underappreciated filler used in a variety of environments. From kitchen floors, backsplashes and countertops to bathroom floors and showers, grout is used in various indoor and outdoor settings. Good grout blends into the background and is virtually unnoticeable; however, when good grout goes bad, it stands out like a sore thumb --- cracking and coming apart, changing colors, lowering the home's aesthetic value and causing potential health problems.

Unused Grout

Damp shower areas with poor ventilation can cause mold to form on grout.

Unused grout is a fine powdery texture with the consistency of baking powder. If it contains hard chunks or if it is in clumps, the grout is either going bad or is already in that state, and should not be used. At this point, the only usefulness the grout can provide is packaging information to ensure that you purchase the identical color and brand of grout needed to match the existing grout.

Floor Tile Grout

Grout is a porous substance that, if not properly sealed, absorbs dirt, grime, mildew and bacteria. And while mopping is generally considered a practical method of cleaning the floor, with grout, this action only serves to move dirt from one place to another. In fact, when you mop the floor, the grout cleans the mop by extracting the dirt and germs from it. Over time, this buildup discolors and weakens the grout and causes it to go bad while possibly endangering your health because mold and mildew can lead to sinus and respiratory illnesses.

Bathroom Tile Grout

In the bathroom, leaky faucets and showerheads can cause grout to deteriorate. Any small holes or cracks are indications that the grout is no longer providing a water-proof barrier, and these subtle warnings can lead to expensive plumbing problems if not heeded. Also, damp shower areas with poor ventilation can cause mold to form on the grout, confirmed by the grout's brownish or black color.

Other Considerations

Bleach is a commonly used solution for mold; however, some grout and tile professionals warn that this is only a temporary solution and recommend steam extraction instead. When it becomes necessary to replace grout, even matching the product and color precisely will not ensure a uniform color because the existing grout has discolored over time. Thoroughly clean the existing grout to restore the original color before applying new grout.