Repairs · Porcelain, ceramic and natural stone

Tile and stone floor repairs

Tile is the most permanent floor and the most local to repair: one tile comes out and one goes in, and nobody can tell. Grout is a wear item that is raked out and redone. The repairs that matter are the ones that are not really tile problems at all — a crack that runs straight across several tiles, or a patch that sounds hollow — because those are the substrate moving under the floor, and a new tile over a moving slab cracks again.

One tile is a repair; a line of tiles is the floor underneath

A single cracked tile, a chipped edge, a stained grout line: those are the tile floor’s equivalent of a scratch, and a homeowner with a grout saw and a chisel handles them in a day. Keep spare tiles from the original order, because the same tile bought later is a different shade and a different size.

A crack that runs in a straight line through several tiles is a crack in the slab or a joint in the subfloor telegraphing up. Grout cracking in long straight lines is the same story, and tiles that sound hollow when tapped have lost their bond. Replacing those tiles without a crack-isolation membrane or a substrate fix repeats the failure; those are the pro calls on this page.

On this page

6 repairs, each with a verdict

DIY a realistic job for a careful person · Hire it the tools or the skill are the job · Replace a repair costs more than it is worth

01 · Tile & stone

One cracked or broken tile

DIYCost $40–120 in tools and materialsTime Half a day plus curing

Why it happened

A dropped pot, a point load, or a void in the thinset under that tile so it had no support. If the crack is in one tile only and the neighbors are sound, it is a tile problem.

How to fix it

  1. Rake the grout out around the tile with a grout saw or an oscillating tool so the neighbors are not levered.
  2. Tape the surrounding tiles, drill a few holes in the center of the broken tile with a masonry bit, then break it out from the center with a cold chisel and a hammer, working toward the edges. Wear glasses.
  3. Chip the old thinset flat and vacuum. Check the substrate for a crack; if there is one under the tile, see the next item.
  4. Back-butter the new tile and set it in fresh thinset, level with its neighbors, with spacers. Let it cure a day, then grout, then seal the new grout after it cures.
When it is not a repair

If the tile broke over a crack in the slab, a membrane goes down over the crack before the new tile does, or the new tile breaks along the same line.

02 · Tile & stone

A crack running through several tiles

Hire itCost $300–1,000+ depending on the lengthTime A day or two

Why it happened

The slab has cracked, or a plywood subfloor joint or a control joint sits directly under the tiles with nothing to isolate it. The crack in the tile is a mirror of the crack underneath. The diagnosis, on Why Floors Fail →

How to fix it

  1. Remove the tiles along the crack, a tile or two wide on each side.
  2. Clean to the substrate and install a crack-isolation membrane over the crack, extending beyond it, per the membrane’s spec — this is what should have been there. Over a control joint, the joint is honored through the tile with a flexible sealant instead of grout.
  3. Reset the tiles, grout, and use a flexible sealant in any joint that lines up with the movement.
When it is not a repair

A slab that is actively moving — one side higher than the other, a crack that keeps widening — is a structural or soil question before it is a flooring one, and a tile repair over it is money spent twice.

03 · Tile & stone

Regrouting cracked, crumbling or stained grout

DIYCost $30–80 for a roomTime A weekend

Why it happened

Grout mixed too wet or too dry, never sealed, cleaned with acid, or simply old. Cement grout is a wear item.

How to fix it

  1. Rake the old grout out to at least two-thirds of its depth with a carbide grout saw or an oscillating tool with a grout blade; new grout over old does not bond.
  2. Vacuum the joints, then damp them lightly. Mix the new grout to the maker’s ratio — sanded for joints over 1/8 inch, unsanded below — or use a pre-mixed acrylic or epoxy grout, which is harder to work and never needs sealing.
  3. Work it in diagonally with a rubber float, wait for it to haze, and sponge it clean with as little water as possible. Two or three passes with a rinsed sponge.
  4. Cure for the stated time, then seal cement grout with a penetrating sealer. Skip the sealer on epoxy grout.
When it is not a repair

Grout cracking in long straight lines is not a grout problem, it is movement underneath; regrouting it fills the crack until next season. See the item above.

04 · Tile & stone

Hollow-sounding or loose tiles

Hire itCost $10–20 a tile for a few; a full re-lay if widespreadTime A day for a few tiles

Why it happened

The tile never bonded — thinset skinned over before the tile was set, the tile was not back-buttered, the substrate was dusty — or the bond has broken from movement or moisture. A hollow tile is a cracked tile waiting for a heel. The diagnosis, on Why Floors Fail →

How to fix it

  1. Tap the floor and mark every hollow tile. A few in one area is a local fix; hollow tiles across the room mean the whole installation is unbonded.
  2. A few tiles: remove them as for a cracked tile, clean both surfaces to sound material, and reset in fresh thinset with full coverage, back-buttered.
  3. A tile that is hollow but intact and not lifting can be left alone in a light-traffic spot, or injected with a tile bonding adhesive through a drilled grout joint — a stopgap that works more often than it should.
When it is not a repair

Hollow tiles across most of a floor mean the tile was set on a substrate that was never going to hold it — dusty, wet, or moving — and the floor is re-laid. Tenting (a ridge of tiles lifted clear of the floor) is the same failure with expansion added, and it is a re-lay with movement joints this time.

05 · Tile & stone

A chipped edge or corner

DIYCost $10–30Time Half an hour

Why it happened

A dropped object on an edge, or a tile edge left proud that catches everything.

How to fix it

  1. Clean the chip and let it dry.
  2. Fill with a two-part epoxy tile repair compound or a color-matched ceramic filler, slightly proud, and shape it with a razor blade as it firms. Some kits include a glaze coat for the sheen.
  3. On a porcelain with a through-body color the chip is barely visible unfilled; on a glazed tile with a white body, the filler’s color match is the whole job.
When it is not a repair

A chip on a tile in a wet area that exposes the body to water, or a chip that has cracked through, is a tile replacement.

06 · Tile & stone

Etched or dull natural stone

Hire itCost $2–5 per sq ft to hone and polishTime A day

Why it happened

Acid — a cleaner, wine, juice, urine — dissolved the surface of a marble, limestone or travertine floor and left a dull spot. An etch is a change to the stone, not a stain on it. The diagnosis, on Why Floors Fail →

How to fix it

  1. Light etches on polished marble: a marble polishing powder worked in with a damp cloth or a low-speed buffer, following the product, sometimes brings the polish back.
  2. Anything more: professional diamond honing to take the surface down past the etch, then repolishing to the original sheen, then resealing. It is done in place and the floor is usable the next day.
  3. Then the cleaning changes: nothing acidic on the floor, ever.
When it is not a repair

Honing removes surface; a stone tile that has been honed many times, or a thin stone veneer, eventually has none to give.

Common questions

Tile & stone repairs — frequently asked

Yes, and it is the classic tile repair: rake out the grout around it, break the tile out from the center with a chisel, clean the thinset flat, set a matching tile in fresh thinset, and grout. Half a day plus curing. The catch is the match — keep spare tiles from the original box, because a tile bought later is a different shade and often a different size.

Because the floor under it cracked in a straight line. A crack through several tiles is the slab or a subfloor joint moving and telegraphing up. Replacing the tiles alone repeats the crack; the repair is a crack-isolation membrane over the crack under the new tiles, or a flexible sealant joint where the movement is.

A few hollow tiles are removed, both surfaces cleaned to sound material, and the tiles reset in fresh thinset with full coverage. A hollow tile that is intact and out of the traffic path can also be injected with a bonding adhesive through a drilled grout joint. Hollow tiles across most of a room mean the floor never bonded and is re-laid.

No. New grout over old is a thin skin that cracks and flakes within a season. The old grout is raked out to at least two-thirds of its depth with a grout saw or an oscillating tool, the joints are vacuumed, and the new grout is packed in fresh. Regrouting a room is a weekend and $30 to $80 in materials.

A two-part epoxy tile repair compound or a color-matched ceramic filler, worked into the chip slightly proud and shaped with a razor blade as it sets; some kits include a glaze coat. It is a good repair on a floor tile away from water. A chip that exposes the body of a tile in a shower or a wet area is a replacement.

One tile, done yourself, is $40 to $120 in tools and materials. A professional charges a minimum visit of $150 to $300 for a tile or two. Regrouting a room yourself is under $100 in materials; a professional regrout runs $2 to $4 per square foot. A crack through several tiles with a membrane is $300 to $1,000 and up. A full re-lay of an unbonded floor is a new floor.

Repairs

Repairs on the other floors