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Tile Lippage, Hollow Tiles and Cracked Grout: What Is Acceptable by the Standard, What Is a Defect, What Caused It, and What It Costs to Fix
Flooring & Tile
Tile Lippage, Hollow Spots and Cracked Grout: What the Standard Allows, What Your Foot Allows, and Whose Fault Each One Is
A tile floor has three ways of telling you something is wrong: an edge you can feel with a bare foot, a tile that sounds hollow when you tap it, and a grout line that cracks. The first has a written tolerance and most arguments about it end when someone reads it. The second is usually nothing and occasionally the start of a floor coming up. The third is almost always the floor under the tile moving, and no amount of regrouting fixes a moving floor. Here is what is acceptable, what is a defect, what caused it and what a fix costs.
Lippage: the number
Lippage is the height difference between the edges of two neighbouring tiles. The standard (ANSI A108.02) allows 1/32 in. when the grout joint is narrower than 1/4 in., and 1/16 in. when the joint is 1/4 in. or wider, in both cases plus whatever warpage the tile itself is allowed to have under its own standard. A sixteenth of an inch is the thickness of a dime. You can feel it with a bare foot. You can see it in low afternoon light. It is also what the standard says is acceptable, so a setter who has met it has done his job even if you do not love it.
What you will not find in any standard is “no lippage”. Tile is not a machined surface. What a good setter does is keep it well under the limit on a floor that was flat to begin with, and keep it uniform, because the eye forgives a consistent 1/32 and catches a single 1/16 at the doorway every time.
| Grout joint | Allowed lippage | About the thickness of |
|---|---|---|
| Under 1/4 in. (most rectified porcelain at 1/8 or 3/16) | 1/32 in. | A credit card |
| 1/4 in. and wider | 1/16 in. | A dime |
| Either | plus the tile’s allowable warpage | Read the carton or the maker’s data sheet |
Measure it the way the standard does: a straightedge across the joint, a feeler gauge or a dime under the low side. Not a photograph with a raking flashlight, which makes a thirty-second of an inch look like a curb.
Where lippage comes from
- A floor that was not flat. 3/16 in. in 10 ft for ordinary tile, 1/8 in. for large format. A setter who did not check it or did not price the levelling owns the lippage. Levelling.
- A brick offset over 33% on tile longer than 15 in. The tile’s own warp lands the middle of one beside the end of the next. Built-in lippage, predicted by the standard. The large-format rules.
- Thinset too thin or the wrong type. The tile sinks unevenly as the mortar collapses. Large tile wants a large-and-heavy-tile mortar.
- Grout joint too tight for the tile. A 1/16 joint on a pressed-edge tile that varies 1/16 in size. The joint is where the size variation goes; too tight and it goes into lippage instead.
Hollow sounds
Tap a tile with a coin and it rings hollow. Sometimes that is an air void under one corner, which the standards address by requiring at least 80% mortar coverage on a dry floor and 95% in a shower or outside, with no voids bigger than a couple of square inches and none at the corners. A hollow corner is where a chair leg cracks the tile two winters from now. Sometimes the hollow sound is nothing: a tile over an uncoupling membrane sounds different from one over a slab, and a tile over a joist sounds different from one between joists, and none of that is a defect.
The test is whether it moves. Press the corners. If the tile rocks, or the grout around it has a hairline, it is not bonded and it comes up. If it is solid and silent underfoot, note it on the walk-through and leave it. A floor with hollow sounds under a third of the tiles is a floor that was not back-buttered and will shed tiles for years; that is a bond failure and a claim, not a cosmetic complaint.
Cracked grout, and why regrouting is not the fix
Grout is cement. It is hard and it does not stretch. The floor under it does: wood swells in July and shrinks in January, a slab shrinks as it cures for a year, a long floor grows in the afternoon sun through a patio door. If nothing in the tile assembly is designed to take that movement, the grout takes it, by cracking. The crack tells you where the floor moved.
A crack in a straight line across the room, through grout and sometimes through tile, is a slab crack or a subfloor seam telegraphing up. Needed a crack-isolation or uncoupling membrane, and did not get one. Cracks at every wall, the tub and the cabinets are the perimeter joint: the standard (TCNA EJ171) wants a soft joint, silicone or a sealant, not grout, wherever tile meets a wall, a change of plane or a different material. Grouted perimeters crack every time; it is the single commonest tile complaint in a new house and the single easiest to have avoided. Cracks and lifted tiles in the middle of a big open floor are a missing movement joint: interior floors want a soft joint every 20 to 25 ft, and every 8 to 12 ft where sun hits the floor, and nobody puts them in because the homeowner does not like the look. Random cracks with a floor that bounces are deflection: the joists or the subfloor are too springy for tile, and the floor needed a second layer of plywood or deeper joists. Crumbly, powdery grout was mixed with too much water or was walked on too soon.
Regrouting a cracked joint over a moving floor buys a year. The fix is the movement joint: cut the grout out of the perimeter and the long runs, fill them with a matching colour silicone, and the cracking stops. On a new house this is a Tarion warranty item in the first year, and the builder’s fix should be the soft joint, not fresh grout. How warranty claims go.
Haze, efflorescence and the rest
Grout haze is a cloudy film on the tile left from grouting and wiped too late; an acidic haze remover takes it off, and it is the setter’s job to come back. Efflorescence is a white powder that keeps coming back on the grout, which is minerals carried by water moving through the floor; on a basement slab it means the slab is wet, and that is a moisture problem before it is a tile problem. Grout colour that varies from batch to batch was mixed with different amounts of water or wiped at different times; it is cosmetic and you live with it or stain it. Grout that stains in the shower is cement grout being cement grout; epoxy grout does not, and it roughly doubles the $1.25 setting-materials line.
What repairs cost
One cracked tile cut out and replaced with a matching spare, regrouted: $150 to $250 as a service call, and it depends entirely on your having kept a box of the tile; this is why I tell every client to keep the leftovers in the basement. Cutting out a grouted perimeter and silicone it, a typical bathroom: $200 to $400. Regrouting a whole bathroom floor: $4 to $6 a square foot, $900 minimum. Re-setting a section of hollow tiles: new tile needed, $900 minimum. The repair cost page has the rest, and if the floor is under a year old, the first call is to the installer, in writing, with photographs and a dime for scale.
Questions people ask
How much tile lippage is acceptable?
By ANSI A108.02, 1/32 in. where the grout joint is under 1/4 in. wide and 1/16 in. where it is 1/4 in. or wider, plus the tile’s own allowable warpage. A dime is about 1/16 in. Anything more is a workmanship defect; anything less is within the standard whether you like it or not.
Why does my tile sound hollow?
Either an air void under part of the tile from poor mortar coverage, or just the sound of tile over a membrane or between joists. If it does not move when you press the corners and the grout is intact, it is not a defect. If it rocks or the grout has cracked around it, the bond has failed and the tile should be reset.
Why is my grout cracking along the walls?
Because it is grout and should have been silicone. Tile meeting a wall, a tub, a cabinet or another floor needs a flexible joint; the house moves and cement grout does not. The fix is to cut the grout out and run colour-matched silicone, about $200 to $400 for a bathroom.
Is cracked grout covered by warranty on a new house?
In Ontario, Tarion’s first-year warranty covers defects in work and materials, and cracked grout at perimeters and missing movement joints are usually accepted when reported in the first year. Shrinkage cracking in grout within normal tolerance is not. Report it in writing before the anniversary.
Can you fix lippage without redoing the floor?
Not really. Grinding the high edge of a porcelain tile takes the glaze off and shows. A tile or two can be lifted and reset; a whole floor over a hump has to come up. The time to fix lippage is the day it is set, which is why the walk-through happens before the final payment.
Before you pay the last cheque
The workmanship inspection page is the walk-through list for tile, hardwood and vinyl, with the holdback rules. If you are still at the quote stage, the tile and shower cost calculator prices the membrane and the levelling that prevent most of this page.
Sources and further reading
- Tile Council of North America: the TCNA Handbook methods for tile over wood, concrete and in showers, and the ANSI lippage and grout standards a tile setter is held to.
- Mapei Canada: thinset, grout, self-levelling compound and moisture mitigation product data: what each one needs from the floor under it.
- Tarion warranty coverage: what a new-home warranty covers for flooring gaps, cupping, cracked tile and squeaks in year one and year two, and the Construction Performance Guidelines it measures them by.
