Regrouting Tile Floors: Kitchen and Bathroom Floors Without the Mess

To regrout a tile floor, first confirm the tiles are solid and the floor does not flex, then remove the old grout to at least two thirds of its depth while capturing dust at the tool. Vacuum and lightly dampen the joints, grout in sections of about 10 to 25 square feet, work toward the exit, and keep foot traffic off for at least 24 hours (longer for heavy loads).

Check the floor before you check the grout

On a floor, grout is the first place movement shows. Cracked grout along a line, grout that crumbles next to the dishwasher, or joints that break out at a doorway are often symptoms of a floor that bends, a tile that lost its bond, or a missing perimeter joint. Regrouting those floors gives you clean joints for a few months before the cracks return.

• Tap test. Drag a steel ball chain or tap with a screwdriver handle across every tile. Mark hollow tiles with tape. A few hollow corners are common; more than about 5 to 10 percent of tiles hollow, or hollow tiles in a line, points to a bond or substrate problem.
• Bounce test. Have someone heavy step or bounce lightly in the middle of the room while you watch the joints at eye level, or feel with a hand on the tile. Visible movement means the subfloor is too flexible.
• Crack pattern. Cracks that run through tiles and grout in a straight line usually follow a crack or joint in the slab, or a seam in the subfloor. See why grout cracks.
• Perimeter. Pull a baseboard or shoe molding in one spot. If the tile is tight to the wall with grout or thinset packed into the gap, there is no room for expansion.

If any of these turn up, read when regrouting won't work before you continue. The overall decision between patching and regrouting is in repair or replace grout.

Dust control on floors

A regrouting job on a 100 square foot kitchen floor with 12 inch tile and 1/8 inch joints removes only about 5 to 8 pounds of grout, but much of it leaves the joint as dust if you use a powered tool without extraction. Cement grout contains crystalline silica from the sand and cement, and the fine fraction from cutting it is respirable. The health background and PPE are in grout safety.

Seal the room. Close doors and tape plastic over openings and HVAC returns, and turn off forced air systems while cutting so dust is not distributed through the house. Mist the work area lightly if using hand tools, but do not flood joints. Clean up with a HEPA vacuum and damp wiping rather than a broom, which puts fine dust back in the air.

Removal depth on floors

Remove at least two thirds of the grout depth, or to sound grout if it is weak deeper down, and leave room for at least about 1/8 inch of new grout. On a typical 3/8 inch porcelain floor tile, that means about 1/4 inch deep. Full depth is better when the grout comes out cleanly. Measure the tile thickness at a threshold or a cut edge before you start, and set a depth stop or a tape mark on your blade.

Know what is under the tile. Many bathroom and kitchen floors installed in the last two decades have an uncoupling membrane, a waterproofing membrane, or electric heat cables in a thin layer of thinset or self-leveler. Cutting into any of those turns a grout job into a tile tear-out. On heated floors, find the cable layout (often on a photo or plan left by the installer) and use hand tools only near the cables. See grouting radiant heated floors. The tool-by-tool removal method is in how to remove grout.

Linear footage drives removal time; grout volume drives material. Use the grout calculator for quantity, and add 10 to 15 percent for regrouting because old joints are rarely uniform in depth.

Grout choice for regrouted floors

Floor grout takes abrasion, point loads and wet mopping. For most kitchen and bathroom floors a sanded high-performance cement grout meeting ANSI A118.7 is the practical choice: better color uniformity, lower absorption and more abrasion resistance than a basic A118.6 grout. Epoxy grout is the most stain resistant option for kitchens with frequent spills, and it is easier to install on a floor than on a wall because gravity helps you. Floor-specific guidance is in floor grout.

Step-by-step floor regrouting

1. Check the floor. Tap-test the tiles, bounce-test the floor and look at the crack pattern. Fix structural issues and reset hollow tiles before regrouting.
2. Clear and protect. Remove the toilet if regrouting a bathroom floor (and plan a new wax ring), pull out movable appliances, and tape the toe kicks of cabinets and the base of the tub.
3. Set up dust control. Seal the room, shut off forced air, connect tools to a HEPA vacuum and put on a respirator, eye protection and knee pads.
4. Remove the grout. Cut to at least two thirds of the tile depth, stopping clear of any membrane or heat cable. Clean the tile shoulders with a carbide scribe.
5. Open the perimeter. Remove grout and debris from the joint along walls, cabinets, tub and thresholds so it can be filled with sealant, not grout, per TCNA EJ171.
6. Vacuum and wipe. HEPA-vacuum every joint, then wipe with a damp brush or sponge to remove fine dust.
7. Plan the sections. Divide the floor into sections of about 10 to 25 square feet, starting at the far corner and working toward the exit. Use grout joints as section boundaries.
8. Dampen and grout the first section. Lightly dampen the joints, then spread grout with a rubber float at 45 degrees, packing diagonally across the joints from two directions. Remove excess with the float edge held nearly upright.
9. Tool and clean. When the grout firms, tool the joints to a consistent profile and clean with a well-wrung sponge in a diagonal motion. Change rinse water often.
10. Move to the next section. Butt each new section to the previous one at a joint intersection. Mix new batches with the same weighed water ratio so the color stays consistent.
11. Remove haze. Buff the haze with a clean, dry microfiber cloth within the window on the TDS, usually 30 to 90 minutes after cleaning.
12. Cure and protect. Keep traffic off for at least 24 hours, keep the room above about 60 deg F, and avoid wet mopping for the time on the TDS.
13. Seal the perimeter and seal the grout. Fill perimeter joints with a color-matched sealant, then apply a penetrating sealer to cement grout after it has cured long enough.

Working in sections around kitchens and bathrooms

Kitchens are the hard case because the floor is often the main path through the house. Split a kitchen into two halves along a natural line (an island, a change in direction of joints) and do one half per day so there is always a dry path. Bathrooms are smaller but have the toilet; pulling it is worth the effort, because grouting around a toilet base leaves a ring of old grout that will look different and often traps moisture. Re-set the toilet on a new wax ring only after the grout has cured enough for foot traffic.

When can you walk on a regrouted floor?

Cool floors, especially slabs in winter, slow all of these. The full timeline is in grout cure time, and temperature effects are in grouting in hot and cold weather. Slide appliances back on hardboard or plywood runners, never on the grout itself.