Out with Old Grout

Tile can be used to create striking, one-of-a-kind designs for walls, floors and countertops. Whether intricate mosaic designs or larger tiles made of natural stone, the wide range of styles, shapes, patterns and colors provide an almost limitless palette of design options. But no matter how you lay it out, tile has an annoying drawback: grout. The porosity of the grout absorbs dirt, moisture and contaminants like germs and bacteria. And dirty grout can give your tile a dingy appearance and even lead to unpleasant odors. Grout can also deteriorate over time, crumbling and breaking apart, requiring a repair.

 Keep it Clean

Cleaning is a much easier job if the grout has been regularly maintained, without allowing a lot of dirt and stain to accumulate. An easy way to maintain the appearance of grout in a brand-new tile installation is simply to use a high-quality dust mop to sweep the floors every day until the grout cures. Otherwise, everyday foot traffic can cause dirt and sand to be ground into the grout mortar before it has hardened.

Grout sealers are available for application to the grout surface after it has thoroughly dried. There are also additives that can be used in grouts at mixing time to promote a stronger, more stain-resistant product when cured.

In addition to dirt, stagnant water can harm tile grout by breeding stain-causing mildew and other fungi. To prevent this, make sure shower stall and bath enclosures are properly ventilated. All corners of shower walls, curbs and sills should be sealed with a silicone-based, mildew-resistant caulk.

To keep it clean on a regular basis, routinely mop or sponge a tile floor two or three times per week with a mixture of one capful of dish detergent and a gallon of hot water. Afterward, just mop up the excess water and allow the floor to dry.

Rotozip with Grout-Removal Attachment

Grout Damage

Dirt is not the only enemy of tile grout. Several things can cause grout to crack and loosen in the tile joint. One reason is excessive deflection in the substrate. Movement in the floor can crack grout and even cause the floor tiles to break. This is a major problem with the installation and will require significant reinstallation rather than simply restoring the grout.

Grout that’s not sufficiently packed into joints can also crack. This is often a problem with wall tile, when the grout isn’t pushed all the way to the back of the joint. This is particularly common with sanded grout in joints narrower than 1/8 inch. The sand grains can bridge a narrow joint on the surface of the tile and appear to fill the joint. However, if the grout is only bridging the surface and not actually installed to the depth of the joint, the grout won’t have much staying power. Excessive water in the initial grout mixture can also lead to cracking.


Grout Cleaning

For “light” grout restoration when cleaning only the surface layer of the mortar, start with an all-purpose cleaner and a nylon scrub pad, or a narrow grout brush. Simple Green and CLR are easy-to-find retail cleaners that do a good job of removing dirt and built-up calcium and lime deposits. Make sure the scrub pad does not damage the tile.

If scrubbing doesn’t work, you can step up to a specialized cleaner that chemically attacks grout. Many of these products are acid-based and should be used carefully. Always follow the manufacturer’s instructions to the letter. Also, avoid cleaners containing harsh abrasives that may damage tile surfaces. And always test the product on an inconspicuous area of the floor.

Vapor cleaning technology is a new trend in grout restoration. Vapor-cleaning machines convert ordinary tap water into a low-moisture, extremely high-temperature water vapor under low pressure to remove soil, grease and built-up filth. These machines heat water to extremely hot temperatures (in excess of 295 degrees F) to produce water droplets hotter and smaller than ordinary steam. This allows the heated vapor to penetrate cracks and crevices and reach areas that ordinary cleaners can’t.


Repairing Grout

If your grout refuses to come clean or it’s crumbling apart, then you’ll need to replace it. And restoring damaged grout can be a real pain in the neck. Joints can’t simply be “grouted over” successfully. At least 2/3 the depth of the old grout needs to be removed when repairing grout. The type of tile impacts the difficulty of grout removal. In general, the more porous the tile, the stronger the bond formed with the grout. Conversely, grout is easier to remove from dense, impervious tiles such as porcelain.

The old-fashioned way to replace cracked or damaged grout is to use a dedicated grout remover or other sharp, pointed tool. These manual cutting tools use triangular heads or metal teeth to dig grout from a joint while minimizing damage to the tile edges. These tools are inexpensive and effective, but the trouble is that they can require a great deal of elbow grease—not a fun tool to use on a big job.

Manual grout saws are inexpensive tools but require a lot of elbow grease to get the job done.

Fortunately, new grout attachments are available for spiral saws, such as the Rotozip and Dremel. If you’re familiar with these tools, then you know how the depth gauge works for the cutting bit. The gauge rests flush against the cutting surface, and the bit is raised or lowered via an adjustable sleeve around the head of the saw. The new grout attachments feature an angled depth gauge to slide smoothly along the tile surface.


The RotoZip grout-removal attachment has a removable base ideal for wall, floor and corner grout lines 1/16” or wider.

These attachments are used in conjunction with special heavy-duty, grout-removal cutting bits. This takes the concept of the hand-operated grout tool and automates it on a power-tool platform. These tools are a heck of a lot easier to use than the hand tools, plus the spiral saws can be configured with various other attachments, making them great shop tools for a wide range of applications. For small to medium grout-removal jobs or detail work, a Dremel with the grout attachment will work nicely. But if you have a large job or you use your spiral saw for other tough, construction-grade chores, then I’d suggest a Rotozip—the tougher of the two tools.



The Dremel grout-removal attachment easily screws in place of the housing cap, keeping the bit at the perfect cutting angle at all times. The special 1/16” bit has a high-speed cutter mounted on a 1/8” steel shaft, ideal for use on both wall and floor grout.

Changing Color

Complete grout removal offers you the opportunity to change the color of the grout. As mentioned earlier, some colorants are added to grout during the mixing phase. There are even grout stains and colorants that can be applied to old grout to change the color. A coat or two of these stains can completely change the look of your tile installation. You can also use them to cover stains and spots. Some good brands for colorant are Mapei, Ameritech, Aqua-Mix and Customs. Staining and colorant procedures vary from product to product, so be sure to follow the instructions.

And after the new grout or stain has dried, apply a silicone-based grout sealer to protect the look of your newly restored floor.

Special colorants can stain grout for a dramatic change in the appearance of a tiled surface.



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