What to Do When Tiles Sound Hollow After Moving In
It usually starts by accident. You drop a set of keys, or you walk across the living room in hard shoes, and one part of the floor answers differently to the rest. A dull, empty knock instead of a solid one.
So you crouch down and start tapping.
Ten minutes later you have found a dozen. Maybe fifty. And the handover agent has already told you, cheerfully, that hollow tiles are completely normal and nothing to worry about.
He might be right. He is often not.
At Prime Inspections, we get asked about hollow tiles more than almost any other single defect. And the honest answer is not the one either side wants. The difference between a normal floor and a failing one is not something you can hear. It is something you have to map.
Are Hollow Tiles a Defect or Are They Normal?
A hollow sound alone does not prove a defect, because some floor build-ups ring hollow legitimately. What proves a defect is the pattern and the extent. Where hollow tiles form a grid that matches the adhesive dabs underneath, or cluster in wet areas, or run along edges and corners, the tiles were not properly bedded. That is a workmanship defect.
Now the part most snagging companies will not say.
Not every hollow tile is a failure. If we told you otherwise, we would be doing exactly what a developer does when they tell you none of them are. Both are ways of avoiding the actual work, which is finding out where the hollow tiles are, how many there are, and what shape they make.
That shape is the whole answer. The rest of this article is how to read it.
What “Hollow” Actually Means
When a tile rings hollow, there is a void underneath it. A gap between the back of the tile and the surface it was supposed to bond to.
The tile is not stuck down across its full area. It is bridging over air.
Where the Voids Come From
In Dubai, the causes are fairly consistent, and most of them trace back to speed and heat.
Dab-and-dot, or spot bonding
Adhesive applied in five blobs, one at each corner and one in the middle, instead of a full combed bed across the whole tile.
It is fast and it uses less adhesive. It also leaves most of the tile floating over nothing. This is the single most common cause we find, and it has a signature you can spot.
Adhesive skinning in the heat
This one is specific to our climate. Tile adhesive begins to skin over as it dries, and in Dubai heat that can happen within minutes of it being spread.
A tile pressed onto adhesive that has already skinned does not key into it. It sits on top of a crust. It looks laid. It is not bonded.
Tiling onto uncured screed
If the screed underneath was tiled before it had properly cured, it keeps shrinking after the tile goes down.
As it shrinks, it pulls away, and it takes the bond with it.
Missing movement joints
Long tile runs and large floor plates need somewhere to move, because floors expand and contract with temperature. That thermal movement is real here.
Leave the movement joints out and the floor relieves the stress the only way it can. It debonds, it tents, or it cracks.
Dust, contamination and no primer
A substrate that was dusty, oily or never primed gives the adhesive nothing clean to grab. The bond fails before anyone has walked on it.
Why You Cannot See Any of This
Here is the frustrating part. The tiles look perfect.
The surface is flat, the grout is neat, the finish is flawless. There is nothing to point at.
That is precisely why this defect gets called cosmetic. It looks like nothing because the problem is underneath, and underneath is exactly where nobody is looking. Which is also why hollow tiles are the defect developers most reliably dismiss.
The Standard: How Much Adhesive Should Be Under a Tile
This is the section to screenshot. If a developer tells you hollow tiles are within tolerance, these are the numbers that let you ask which tolerance they mean.These coverage recommendations are consistent with the Tile Council of North America (TCNA) installation standards.
| Location | Required coverage | Why it matters |
| Interior floors, dry areas | Around 80%, solidly bedded, no voids at corners or edges | Load distribution. A corner void is where a crack starts. |
| Wet areas: bathrooms, kitchens, laundries | Full coverage | A void in a wet area holds water. Water in a void does not dry. |
| External areas: balconies, terraces | Full coverage | Severe heat cycling. Voids fail fastest where the sun hits hardest. |
| Large-format tiles | Full bed, back-buttered | The bigger the tile, the less forgiving a void becomes. |
If your developer tells you the hollow tiles are within tolerance, ask them which tolerance. Then ask them to show you the coverage.
Why It Matters, Even Though Nothing Is Broken Yet
The obvious objection is fair. The floor looks fine and nothing has cracked. So why fight about it?
Because a hollow tile is not a problem you have. It is a problem you are going to have.
A Void Is an Unsupported Span
A properly bedded tile is supported across its whole underside. A hollow tile is bridging a gap.
Put a load on that gap, a chair leg, a dropped pan, the wrong footstep, and the tile has nothing underneath to push back. It cracks.
In a Wet Area, a Void Is a Reservoir
Water finds the void through the grout line and then it stays there, because a sealed gap under a tile has nowhere to drain and no air to dry it.
Over time that trapped moisture works on the adhesive, the grout, and whatever waterproofing sits below. A hollow tile in a bathroom is a slow leak waiting for a location.
In a Long Run, It Is Where the Floor Fails First
When a floor without proper movement joints finally moves, it fails at its weakest point. A debonded tile in the middle of a long run is that weakest point.
One hollow tile becomes a cracked tile, and a cracked tile in a run becomes a tented row.
And Here Is the Argument That Wins the Dispute
This is the paragraph that matters most.
Hollow tiles very rarely fail during the defects liability period. They hold together through year one, while the developer is still responsible for them.
They fail in year two, year three, year four. After the developer’s obligation has expired, and after the cost of putting it right has quietly become yours.
So when a developer tells you to wait and see how the floor performs, understand what is actually being said. They are not being reasonable.
They are being patient. The clock is on their side, and waiting is how they win.
This is what “cosmetic” really means when a developer uses the word. A defect that looks like nothing today and costs you thousands the year after their warranty ends. We wrote a separate guide on the cosmetic label and how to push back on it, because hollow tiles are the clearest example of it there is.
How to Test Your Own Tiles
You can do a real version of this yourself before you call anyone. Done properly, it turns a suspicion into a survey.
The method matters more than the tool. Here is how to do it so the result actually means something.
- Use the back of a knuckle, a coin, or a proper sounding rod. Not a hammer. You are listening for a change in tone, not trying to break anything.
- Work in a grid, not at random. Tap every tile, and tap each tile in five places: the four corners and the centre. This one habit is what separates a survey from a guess.
- Mark what rings hollow. Low-tack tape or a wax pencil. Never anything that stains a brand new floor.
- Photograph the map. A floor plan with the hollow tiles marked on it is evidence. A memory of tapping is not.
- Count it. Record what percentage of the floor is affected, and note where the affected tiles sit.
- Read the pattern. Hollow at the corners and solid in the centre is the signature of dab-and-dot. Whole tiles hollow across a run points to a bedding or curing failure. Hollow along one wall may be a screed or movement issue.
- Check the wet areas separately. Treat any hollowness in a bathroom, kitchen or laundry as more serious than the same finding in a dry hallway.
- Do not lift anything. And do not let anyone else lift anything until the full extent has been recorded. Once a tile is up, the evidence of how widespread it was is gone.
If your own test throws up a repeating corner pattern across most of a room, you already have your answer. That is not a few unlucky tiles. That is how the floor was laid.
Can Hollow Tiles Be Repaired, or Do They Have to Be Replaced?
This is where owners panic, because they picture the entire floor coming up. Often it does not have to. It depends on the extent, and this is genuinely a case-by-case answer.
Injection
Low-viscosity resin is injected through the grout line to fill the void under the tile.
For isolated tiles with limited voids, this is a legitimate repair. We will not pretend it is not. Done well, it bonds the tile back down without lifting anything.
Lift and Re-lay
Required where the voids are extensive, roughly half the tile or more, where the pattern is clearly systemic, or in wet areas where the waterproofing beneath the tile may also be compromised.
If most of the floor was never bonded, injecting a few hundred tiles is not a repair. It is a delay with a resin bill attached.
Why the Developer Will Always Offer Injection
It is the cheapest option, and it closes the snag quickly. Sometimes that is the right call. Sometimes it is the option chosen precisely because it is the cheapest one that lets them mark the item complete.
The way to tell the difference is the extent, which is exactly why the map comes first. You cannot decide the right repair until you know the true scale of the problem.
What a Proper Fix Looks Like
The void filled or the tile re-bedded. The grout made good. And then, the part everyone skips, a re-test afterwards.
If they cannot tap it again in front of you and show it rings solid, it is not fixed. It is just closed. Verifying the fix is as important as the fix itself.
What to Do If the Developer Says They Are Normal
You have heard the line. Here is the sequence that answers it, in order.
Get the Extent Recorded Independently
A map and a count from a third party carries weight that your own tapping does not. It is a document, not a complaint, and a document is much harder to wave away.
Put It in Writing and Ask for the Coverage Specification
Email the developer, attach the mapped report, and ask them to confirm the adhesive coverage specification for the floor.
The request itself changes the conversation, because now they are the ones being asked to produce evidence.
Watch for a False Closure
If they mark the tiles as inspected and closed without ever re-testing them, that is a false closure.
A snag is not closed because someone typed “closed.” It is closed when it has been re-tested and shown to be solid.
Use Your Defect Liability Period While You Have It
If you are still inside your defect liability period, this is exactly the situation that period exists for. Do not let it run out while you are being told to wait and see.
If a Contractor Laid Them, Not the Developer
If your tiles were laid by a contractor you hired directly during a fit-out or renovation, the responsibility and the payment leverage sit differently. A Contractor Work Inspection before you release final payment is the right move there.
The Floor That Sounded Fine and Was Not
Here is a pattern we see so often it is almost a routine.
A handover appointment, a good-looking apartment, a living room floor that the agent taps in six places, right down the middle, to demonstrate it is perfectly solid. Six solid knocks. Nothing to see here.
Then the grid survey starts.
Tapped properly, corner by corner, the hollowness turns up at the edges of almost every tile, in a repeating pattern across the whole room. Solid in the centre, hollow at all four corners, tile after tile.
That pattern has only one explanation. Five dabs of adhesive per tile. One dab under the centre, and nothing under the corners.
The agent had, entirely by accident, tapped the one part of every tile that was actually stuck down. The centre rang solid because the centre was the only place with adhesive under it.
The floor was not fine. It was dab-and-dot from wall to wall, and it would have started cracking at the corners within a couple of years.
The lesson is simple. How you test decides what you find. And a developer’s test is designed to find nothing.
Frequently Asked Questions
Why do tiles sound hollow?
A tile sounds hollow when there is a void between the tile and the surface beneath it, so the tile is bridging a gap rather than being fully bonded. In Dubai this usually comes from dab-and-dot bedding, adhesive skinning over in the heat, tiling onto uncured screed, or missing movement joints.
Are hollow tiles normal in a new build in Dubai?
A small number of isolated hollow tiles can occur legitimately. What is not normal is a repeating pattern, a high count, or hollow tiles clustered in wet areas or along edges and corners. That pattern indicates the tiles were not properly bedded, which is a workmanship defect, not a normal characteristic.
Are hollow tiles a cosmetic defect or a real one?
They are a functional defect, not a cosmetic one, even though the floor looks perfect. A void is an unsupported span that cracks under load, and in wet areas it traps water. Hollow tiles are one of the clearest examples of a defect that gets wrongly labelled cosmetic so it can be dismissed.
How many hollow tiles are acceptable?
There is no single official number, which is why the pattern matters more than the count. A few isolated tiles with minor voids may be acceptable. A repeating corner pattern, extensive voids of roughly half the tile or more, or any hollowness in wet areas points to a bedding failure that should be rectified.
What happens if I leave hollow tiles alone?
They tend not to fail immediately. They fail later, typically in year two, three or four, once the developer’s defect liability period has ended and the repair cost has become yours. A hollow tile is a crack, a trapped leak, or a tented row waiting for time and load to arrive.
Can hollow tiles be injected instead of replaced?
Sometimes. Low-viscosity resin injected through the grout line is a legitimate repair for isolated tiles with limited voids. It is not a fix for a floor that was never properly bonded. Where voids are extensive or systemic, or waterproofing is in question, the correct remedy is to lift and re-lay.
How do you test tiles for hollowness properly?
Tap every tile with a coin, knuckle or sounding rod, and tap each tile in five places: the four corners and the centre. Work in a grid, not at random. Mark and photograph everything that rings hollow, count the affected area, and read the pattern. Testing at random misses the corner voids entirely.
Is my developer responsible for hollow tiles?
If a developer laid the tiles and they were not properly bedded, that is a workmanship defect that falls within your defect liability period. Document the extent independently, submit it in writing, and ask for the coverage specification. If a contractor you hired laid them, the responsibility and payment leverage sit differently.
Can hollow tiles cause cracks later?
Yes. A void leaves the tile unsupported, so any concentrated load, a chair leg, a dropped object, a heavy footstep, can crack it. In long runs without movement joints, a debonded tile is often where the whole floor begins to fail. Cracks in year three are frequently tiles that rang hollow in year one.
Map It Before You Argue About It
The strongest position you can be in with a developer is not a strong opinion. It is a strong document.
What we give you is the map. A counted, located, photographed record of every hollow tile in the property, with the coverage argument attached, in a report the developer has to answer rather than dismiss.
Prime Inspections is a RERA approved, DLD and DED registered snagging company with InterNACHI certified engineers, serving Dubai, Abu Dhabi, Sharjah, Ajman, Fujairah, Ras Al Khaimah and Umm Al Quwain. Reports are delivered within 24 hours.
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- Email: connect@primeinspections.ae
- Office: The Binary by Omniyat, Business Bay, Dubai
- Website: www.primeinspections.ae
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