Who this guide is for
- Homeowners who notice tiles that sound hollow underfoot
- People preparing to brief a tiler about debonded tiles
- Anyone wanting to catch loose tiles before they crack or lift
- Owners wanting a clear record before a tiling assessment
Finding the hollow tiles
Tap gently across the floor with a knuckle or the handle of a tool and listen for the change from a solid 'tick' to a hollow 'drum'. Walk the floor and note where it feels or sounds different.
You are mapping a sound, not deciding why the bond failed; a tiler interprets that.
- A drumming sound versus a solid tick
- Tiles that feel slightly loose underfoot
- Hollow zones clustering in one area
- A single hollow tile among solid ones
Mapping the pattern
Mark the hollow tiles on a sketch of the floor. Note whether they cluster, follow a line, sit near a doorway or a wet area, or are scattered. A cluster can point to a substrate or moisture issue.
Record how many tiles are involved and whether the zone seems to be growing.
Related signs to record
Note any cracked grout around hollow tiles, any tile that rocks or has lifted, and any lippage. These often travel together and help a tiler judge the situation.
Whether the area has been wet or near a leak is also worth recording.
Photographing and tapping safely
Photograph the mapped area and any cracked grout or lifted edge. A short video of the tapping can convey the hollow sound. Tap gently — do not strike tiles hard, which can crack them.
Note the room and which tiles you found hollow so a tiler can verify.
- Film the tapping to convey the sound
- Capture cracked grout and lifted edges
- Tap gently, never strike hard
Briefing a tiler
Bring your floor sketch, the video, and notes on related signs before contacting a tiler.
Let them assess whether it is isolated debonding or a wider issue; your record helps them gauge scope before lifting anything.
Documentation checklist
- 1Tap gently across the floor and note where the sound goes hollow
- 2Mark the hollow tiles on a floor sketch
- 3Note whether they cluster, follow a line, or are scattered
- 4Record proximity to doorways, wet areas or known leaks
- 5Note any cracked grout, rocking or lifted tiles nearby
- 6Record whether the hollow zone seems to be growing
- 7Film the tapping and photograph related signs
- 8Tap gently so you do not crack any tiles
Common mistakes to avoid
- Striking tiles hard to test, which can crack a sound tile
- Lifting or re-bedding a hollow tile before a tiler assesses the pattern
- Recording one hollow tile and missing a spreading cluster
- Ignoring cracked grout and lippage that accompany the hollow sound
- Assuming isolated debonding when the substrate may be involved
When to involve a professional
- A tiler can assess whether hollow tiles are isolated or a wider debonding or substrate issue
- If hollow tiles cluster near a wet area, mention it, as moisture under the floor may need checking
- Avoid lifting tiles before assessment, as it can spread the debonding and hide clues
- What is involved varies by tile, substrate and installation, and a professional should confirm the cause
Frequently asked questions
Questions readers ask about this topic
Does a hollow-sounding tile mean it will crack?
A hollow sound usually means the tile is no longer fully bonded, which can lead to cracking, lifting or rocking over time. Mapping the hollow zones early lets a tiler assess and act before that happens.
How hard should I tap to test?
Gently — a knuckle or a light tool handle is enough to hear the difference between a solid tick and a hollow drum. Striking tiles hard can crack a sound tile, so keep it light.
Should I lift a hollow tile to look underneath?
No — lifting tiles tends to spread the debonding and can hide the pattern a tiler needs. Map the hollow tiles, film the tapping, and let a professional decide whether to lift any.
Why do hollow tiles cluster in one spot?
A cluster can point toward a substrate or moisture issue rather than isolated setting. Note where the cluster sits and any nearby wet area, and let a tiler judge whether the substrate needs checking.
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