Tile Grout Replacement

Q: How can I fix cracked tile grout on the walls and floor of the bathroom in the 8-year-old house I just moved into? Is this a do-it-yourself proposition?

A: Tile grout is definitely something you can replace yourself, but there's something you need to understand before you get going. It's possible that the cause of your grout failure goes beyond poor grout itself. It could be that slight movement of the tile on an inadequate subfloor or walls is the cause. If that's the case, then the new grout would fail eventually, too. That said, re-grouting is still the best way to go right now. Your first step is to remove all the old grout, and this may be easy or difficult depending on what you have. Any hardware store can sell you a claw-shaped, carbide-tipped hand tool designed for removing old grout, and this is practical on small areas with loose grout. But if the hand tool proves too slow or tiring, there are power tools designed to do the job. The best I know is called the Multimaster, made by a European company called Fein. It's a multi-purpose sanding, polishing and abrasive tool that’s also made to power an attachment especially for grout removal. When you've got all the old grout out, vacuum the area thoroughly to remove dust and grit, then get ready to apply new grout. The process involves mixing the powdered grout to the consistency of gritty peanut butter, forcing it into the tile gaps with a rubber or wooden trowel, then wiping off the excess grout with a damp sponge as it starts to harden. There are subtleties involved in grouting success, so you'll need more info than I can give here. The best source I've found is a book called Setting Ceramic Tile by Michael Byrne.