You walk across the living room and hear a dull, drummy sound under one patch of floor. Or worse, you wake up to a loud crack and find two tiles lifted into a little tent. Both problems are common in Singapore homes, including HDB flats, and both come from the same root issue: the tile has lost its grip on the floor beneath it. This guide explains what causes the problem, how to judge how serious it is, and which hollow floor tiles fix suits your situation.
This is a different fault from a chipped tile or tired grout. If your tile is cracked on the surface but still firmly bonded, see our guide on fixing a chipped or cracked tile instead.
Hollow Tiles vs Popping Tiles: What Is Happening
A floor tile is held down by a bed of adhesive or mortar on top of a screed (the levelled cement layer over the concrete slab). When that bond weakens, two things can happen.
- Hollow tiles: The tile is partly or fully detached from the bed, but it stays flat. You hear a hollow, drum-like sound when you tap or walk on it. It may stay like this for years without getting worse.
- Popping or tented tiles: Stress builds up across a group of tiles until they push against each other and lift, often suddenly and loudly. The tiles rise into an A-shape or “tent”, sometimes cracking along the edges.
Hollow tiles are often the early stage. Popping is what can happen when a large area of hollow tiles is also under compression.
Common Causes in Singapore Homes
Several factors usually work together. The most common include:
- Incomplete adhesive coverage: If tiles were laid with dabs of adhesive at the corners and centre rather than full coverage, there are air pockets underneath. These areas sound hollow and are weaker over time.
- Temperature changes: Tiles, adhesive and concrete expand and contract at slightly different rates. Floors near windows or balconies that get strong afternoon sun see more movement.
- Missing or inadequate movement joints: Large tiled areas need room to expand, especially at the edges along walls. If tiles are butted tight against walls with no gap, stress has nowhere to go.
- Ageing of the bond: Older flats, especially those with original flooring from decades ago, may simply have adhesive or mortar that has deteriorated.
- Moisture: Water seeping under tiles from wet areas, leaks or frequent mopping with lots of water can weaken some bonding materials.
- Slab or screed movement: Minor settlement or shrinkage in the screed can cause cracks underneath that loosen tiles above.
- Overlaid tiles: Laying new tiles directly over old ones adds another layer that can fail if the old layer was already loose.
Popping often happens in the hotter months or after a sudden temperature swing, which is why some households report it in clusters at certain times of the year.
How to Check Your Floor
You do not need special tools to get a rough idea of the problem.
- Do a tap test. Gently tap each tile with a coin, a key or the handle of a screwdriver. A firm tile gives a sharp, solid click. A hollow tile gives a dull, drummy sound.
- Map the hollow area. Use masking tape to mark hollow tiles. One or two isolated tiles is a different situation from a whole band across the room.
- Look for lifting. Check edges with a straight ruler or spirit level. Even a slight rise or a hairline crack along grout lines can be an early warning.
- Check the grout lines. Grout that is crushed, cracked or pushed up between tiles suggests compression.
- Note the location. Is it near a window, a wet area or along a wall? This helps a contractor diagnose the cause.
Take photos with your marked tape before you call anyone. It makes quotes more accurate and is useful if you need to raise the issue with HDB or a developer.
Safety First if Tiles Have Popped
Tented tiles can be sharp and unstable. If tiles have popped:
- Keep children, older relatives and pets away from the area.
- Do not stand or jump on the lifted section to “press it back down”. This can shatter the tiles and cause cuts.
- Cover the area with a sturdy board or cordon it off with furniture.
- Avoid dragging heavy furniture over the area.
- Sweep up any fragments carefully with gloves on.
Repair Options Compared
Which fix makes sense depends on how many tiles are affected, whether they have lifted, and how much you care about matching the existing floor.
| Repair option | Best for | What to know |
|---|---|---|
| Leave and monitor | A few hollow tiles that are flat, uncracked and not spreading | Mark them, re-check every few months, and act if they start lifting |
| Epoxy or resin injection | Hollow but intact tiles in a limited area | Small holes are drilled at grout lines and filler is injected; less disruptive, but results depend on the cause and the installer |
| Lift and relay affected tiles | Popped or cracked tiles in one area | Old adhesive is removed and tiles relaid with full coverage; matching spare tiles may be hard to find |
| Re-tile the whole floor | Widespread hollowness or repeated popping | Most disruptive and costly, but deals with the underlying problem across the room |
| Overlay with vinyl or other flooring | Floors that are flat and stable but tired-looking | Not suitable over tiles that are actively lifting, as movement continues underneath |
Keep spare tiles. If you are renovating, ask your contractor to leave a box of extra tiles. Matching an older tile years later can be very difficult.
Why Proper Relaying Matters
If tiles are lifted and relaid, ask the contractor how they will prevent a repeat. Good practice generally includes:
- Removing old adhesive fully and checking the screed is sound.
- Using adhesive suitable for the tile type and size, applied for full coverage rather than spot dabs.
- Leaving perimeter gaps along walls and adding movement joints in large areas where appropriate.
- Allowing proper curing time before heavy use.
Ask what warranty the contractor offers on workmanship and get it in writing.
HDB Rules and Who to Contact
For new HDB flats, check whether you are still within the defects liability period. During this period, HDB may handle certain defects, including some tile problems. Report the issue through the official HDB channels and check the current coverage and process on the HDB website, as terms can change.
For older flats or after renovation, the repair is generally the owner’s responsibility. A few points to keep in mind:
- Use an HDB-registered contractor. HDB maintains a directory of registered renovation contractors, and works in HDB flats must follow HDB renovation guidelines. Some flooring works may need a permit, so check the HDB website or ask your contractor before work starts.
- Ask about the original installer. If tiles popped soon after a renovation, contact the contractor who did the job and check your agreement for any warranty.
- Condominium owners: If the issue involves common property or the slab, contact your MCST (Management Corporation Strata Title, the body that manages the condo) to find out what falls under the owner and what falls under the estate.
If you are choosing new flooring as part of the fix, our guide on how to choose tiles for your home covers material and finish options suited to a humid climate.
Preventing Hollow Tiles in Future
- Mop with a damp mop rather than flooding the floor with water.
- Fix leaks from bathrooms, kitchen sinks or air-conditioner pipes quickly.
- Use curtains or blinds to reduce strong direct sun on large tiled areas.
- During renovation, ask about adhesive coverage and movement joints before tiling starts.
- Do a quick tap test every year or so and keep notes, so you can spot changes early.
For more small repairs that suit Singapore’s climate, see DIY fixes for a humid tropical home.
Further reading: How to Choose Peel and Stick Floor Tiles in Singapore