Project library · Home repair · Adult mode
Why my new tile is lifting
The floor went down weeks or months ago and now a tile rocks, sounds hollow, or a whole row has risen into a ridge.
Tile almost never fails on its own. It fails because it had nowhere to move, or because there was never enough adhesive under it.
Before you start
Cutting a joint into a floor means silica dust and a spinning blade. Wear a P2 or P3 mask and eye protection, and find out what runs in the screed before you cut. Heating pipes and cables live in there.
Zero Cost
Diagnose before you spend anything. The cause decides the fix.
$0 · 1 hour
You have it
- A coin or the handle of a screwdriver
- Tape measure
- Chalk or masking tape
You need it
- Nothing
- 1
Tap every tile with the coin. A dead click is bonded, a drummy echo is not. Mark the hollow ones with tape.
- 2
Look at the shape of the failure. A ridge or tent across the middle of the room is movement, not bad adhesive.
- 3
Check the perimeter. Run a knife into the gap at the wall. Grout or tile touching the wall all round means the floor cannot expand.
- 4
Count how many tiles are affected. Under 5 scattered tiles is a bonding problem. A whole line is a movement problem.
- 5
Lift one loose tile and look at the back. Adhesive on less than about 80 per cent of it, in ridges rather than a bed, is the answer.
Minimal Effort
Re-bed the few loose tiles and give the floor room to move at the edges.
About $40 · An afternoon, plus overnight to set
You have it
- Grout rake or old screwdriver
- Notched trowel
- Rubber mallet
You need it
- Small tub of ready-mixed flexible tile adhesive
- Matching grout
- Colour-matched flexible silicone
- Multi-tool or grout blade
- 1
Rake the grout out around each marked tile, then lift the tile with a suction cup or a bar under one corner.
- 2
Scrape the old adhesive off the floor and off the back of the tile. Down to the substrate, not down to a lump.
- 3
Butter the back of the tile fully and comb the floor. Full coverage, not 5 dabs in the corners.
- 4
Set it flush with its neighbours, leave it overnight, then grout.
- 5
Rake the grout out of the perimeter joint at every wall. Fill that gap with flexible silicone instead. Skirting hides it.
Polished Finish
Strip the failed area, fix what caused it, re-lay so it does not come back.
About $250 in materials for 5 square metres · 2 weekends
You have it
- Drill
- Trowel
- Level
- Bucket
You need it
- Uncoupling membrane
- Flexible S1 or S2 powdered adhesive
- Movement joint profile or flexible sealant
- Notched trowel matched to the tile size
- Replacement tiles for breakages
- 1
Take the whole failed area up, back to a clean substrate. Trying to save 3 tiles in the middle of a bad bay wastes the work.
- 2
Establish why it moved. Wood floors deflect, new screed shrinks, and rooms over about 8 metres or in direct sun need an intermediate joint.
- 3
Lay uncoupling membrane over the substrate. It lets the floor beneath move without dragging the tile with it.
- 4
Mix S1 or S2 flexible adhesive to the bag, comb one square metre at a time, and back-butter large formats.
- 5
Lift one tile as you go and check coverage. Under 80 per cent means the wrong trowel or adhesive that skinned over.
- 6
Leave a 6 to 10 mm joint at every wall and at every doorway, and fill it with sealant or a profile. Never grout.
The step that bites
The perimeter joint
This is where most floors are lost. Tile expands, the room shrinks, and if grout runs from tile to wall the floor has nowhere to go but up. It shows as a tented ridge months later, usually after the first hot week or the first time the heating runs. Cut the perimeter free and seal it flexibly, even on a floor you are only patching.
Further reading
Other people have filmed and written this job well. Their work, their names, their links.
- Tenting FAQ
Tile Council of North America
- Tile Tenting and Popping Up: Causes, Diagnosis, and the Proper Fix
Tile Pro Calculator
- 6 Reasons for Tiles Popping Up and How to Fix Them
MYK Laticrete
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