Can You Refill Missing Grout in Tile Flooring?

Bonding Issues

• One of the primary issues with regrouting a section of a grout joint is that the new grout will have a difficult time bonding to the old grout unless specific steps are taken. Not only does the area need to be completely cleared of any old grout, dirt and debris, but the old grout needs to be moistened with water so the new grout's concrete and polymers have something to bond to when they are pushed into the joint against the old grout.

Color Fading

• Color fading is another issue with regrouting, and while you can fill voids in floor tile projects with new grout, it will always have a different color from the old grout. Older grouts have had time to fade with time, and even if you are using the same color and brand of grout, there will be differences because the new grout's polymers are fresh and lack the exposure to wear and tear of the old grout.

Polymer Mixture

• The proper method of grouting a floor is to mix the entire bag of grout in one go, even if you are only grouting a small section. The reason for this is that the polymers and color additives within a bag are meant to be mixed in total, not in parts. If you only use a partial mixture, you run the risk of the colors being completely off, or not enough concrete and other binding elements mixing together.

Underlying Issues

• While you can refill any void in the grout lines with new grout, you need to understand the underlying issues for the grout falling out in the first place, or you could be faced with regrouting the regrouted section mere weeks down the road. If you have voids in your grout, determining the underlying issues is vital to the longevity of the overall project, as well as your new addition. Check for weak tiles or bad underlayment, and fix those issues before you regrout.