Uneven grout color is not normal. However, there are a number of things that can give it an uneven appearance. The easiest colors to work with are beiges and grays. The brighter the color, the more difficult it is to balance. And since most grout is cement based, it tends to gray over time. Other things that can cause color variation include:
- Too much water used when mixing the grout
- Not cleaning the grout and tile properly after cured
- Leaving plastic spacers in the joints
- Having adhesive fill part of the joint and showing through a light colored grout
- Improper mixing of the grout
- Not having enough grout and having to remix it
- Using grout from a bag that was previously opened and gained moisture during storage
- Improper joint packing
- Inadequate cleaning of the sponges
- Using dirty water
- Defective grout
- Dirty tools
- Foot traffic before the grout has cured
Also remember that different tiles have different properties, and will create different effects with the grout. If tiles are porous, for example, they may take the moisture out of the grout too fast, causing irregular patterns.
In some cases, uneven grout color can actually add to the originality of your flooring. When absolute color uniformity is desired, epoxy grouts are often recommended as they cure and clean up differently than cementitious grouts.
What questions do you have about grout color?