Cracked Bathroom Tiles And Whether One Can Be Swapped

A single cracked tile is one of the few bathroom faults where a neat local repair is genuinely possible. A tiler can cut one tile out and put a new one in without disturbing its neighbours, and done well it is hard to spot. The catch is that half the cracked tiles we are called to look at did not crack because something was dropped on them. They cracked because something behind them moved, and replacing the tile without dealing with that guarantees a repeat.

Read the crack before you touch it

An impact crack radiates from a point, often with a small chip or star at the centre, and it stops at the edges of that one tile. A movement crack runs dead straight, frequently continues into the tiles either side in a line, and often follows a joist, a joint in the boards or the line of a doorway. Tap around the tile with a knuckle as well. A hollow sound means the adhesive bed has failed and the tile was unsupported, which is a cause in itself.

The three usual causes

1. Impact. A shampoo bottle or a dropped tap. Contained to one tile and safe to replace on its own.
2. Deflection. Floor tiles laid straight onto floorboards or thin ply will crack as the floor flexes underfoot. Boards need to be rigid, and generally overboarded or replaced with tile backer before tiling.
3. Missing movement joints. Tiles laid tight into a corner or across a structural joint with no flexible joint have nowhere to expand, so they crack or tent up.

How a single tile is replaced

1. Rake the grout out of all four joints with a grout removal blade, right down to the tile edge, so the neighbours are not being pulled on.
2. Drill a few holes in the centre of the damaged tile, then break it out from the middle towards the edges in small pieces.
3. Chisel the old adhesive bed back to a flat, sound surface. Check for damp board behind while it is open.
4. Dry fit the new tile so it sits level with its neighbours, adjusting the adhesive depth rather than forcing it.
5. Bed it with a suitable flexible adhesive, keep the joint widths even, and leave to set.
6. Grout the four joints, then sponge off. Expect a slight tone difference until it weathers.

It is a careful hour or so of work. The risk to a confident DIYer is cracking the tiles next door while chiselling, so slow removal from the middle outwards matters more than anything else.

When a patch is the wrong call

• Several tiles cracked in a line, which means movement.
• Hollow sounding tiles across a whole area, which means the bed has failed.
• Damp, dark or soft board revealed behind the tile.
• The same tile cracking for the second time.
• No matching tiles available and the area is highly visible.

In those cases the honest answer is to strip the affected area, get the substrate right and retile. It costs more on the day and less over five years.

Getting the substrate right in older Stoke housing

A lot of the terraces and 1930s semis around the city have springy timber first floors that were never intended to carry rigid tiling. Where we tile those floors we either overboard with a proper tile backer or use an uncoupling membrane so any small movement in the floor does not reach the tile. The same thinking applies on walls, where old lath or crumbling plaster needs boarding rather than tiling straight onto it.

Talk it through

Send a photo of the crack through the enquiry form and we will tell you whether it is a swap or a symptom. Our tiling service covers repairs, single rooms and full refits across Stoke-on-Trent, Newcastle-under-Lyme, Stone and Leek, with a free survey and a fixed written price.

Common questions