Why tiles crack in the first place
Impact damage, such as a dropped item in the bathroom, is the most obvious cause and usually only affects one tile. The crack pattern from an impact tends to radiate from a point of contact.
A hollow bed underneath the tile is a very common hidden cause. If the adhesive did not fully support the tile when it was laid, the tile flexes slightly under weight and eventually cracks, often along a straight line rather than radiating from a point.
Movement in the substrate, for example a suspended timber floor that flexes more than a solid floor, can crack tiles laid without a flexible movement joint or without a suitable flexible adhesive and deflection-resistant backer board.
Tiling onto a new floor screed before it has fully cured and dried out is a classic cause of cracking weeks or months later, as the screed continues to shrink slightly as it dries and puts stress on the tiles above it.
No movement joint at the perimeter of a room or across a large floor area means the whole tiled surface has nowhere to expand and contract with temperature changes, and cracks can appear at natural weak points.
Step-by-step: removing the damaged tile
Rake out the grout on all four sides of the tile using a grout rake, multi-tool with a grout blade, or a stiff flathead screwdriver, taking your time near the edges of neighbouring tiles.
Score a cross or grid pattern into the cracked tile with a tile scorer or angle grinder fitted with a diamond blade, cutting through the glaze without going deep enough to damage the substrate below.
Break the tile from the centre outwards using a hammer and cold chisel, working inward to outward. Breaking from the centre first reduces the risk of the tile lifting and damaging its neighbours, which is far more likely if you start by prising at the edges.
Once the pieces are out, chisel away the old adhesive bed carefully, keeping the chisel angled away from the surrounding tiles and the substrate underneath. Vacuum out the dust and debris before checking the area is flat and sound.
Comb fresh adhesive onto the back of the new tile, or into the recess for a floor tile, and bed it in level with the surrounding tiles using spacers to keep consistent joint widths. Check level with a straight edge or a small spirit level across the repair.
Matching tile and grout colour
If you kept spare tiles from the original installation, that is the best option, though even the same tile can vary slightly with UV exposure and general fading over time, especially near a window.
If you do not have spares, take a broken piece and, ideally, the tile's box or product name to a tile showroom to find the closest match. Be aware that tiles are manufactured in batches, and colour, shade and even size can vary noticeably between batches, even with the same product name and range.
For grout, buy a small tub in the closest matching colour and test it in an inconspicuous spot first, since grout also dries a shade or two lighter than it appears when wet.
Why chip fillers are only a temporary measure
Tile chip repair kits and coloured epoxy fillers can disguise a small chip reasonably well and are a fair short-term fix, particularly on a wall tile where there is no structural load. However, they do not restore the tile's strength, they can discolour over time, and on a floor tile in a high-traffic area the filler will wear faster than the surrounding glaze. For anything beyond a small cosmetic chip, replacing the tile is the more durable option.
Floor tiles versus wall tiles
Floor tile replacement is generally more demanding because floor tiles carry foot traffic and sometimes furniture weight, so the new tile must be bedded fully level with its neighbours to avoid a trip edge or uneven wear. Floor tiles are also more likely to be a large format or natural stone product, which can be harder to source an exact match for and more prone to chipping at the edges during removal.
Wall tile replacement is usually more straightforward since there is no load-bearing consideration, though care is still needed around tiled corners, external trims and any tiles adjoining a shower enclosure or bath edge where sealant rather than grout is used.
Where to read next
Questions we get asked most
Can I replace one cracked tile myself?
Yes, replacing a single tile is a manageable DIY job if you work carefully, particularly breaking the tile from the centre outward to protect its neighbours. If several tiles nearby are also cracked or hollow-sounding, it is worth investigating the cause before continuing.
Why did my new tile crack again after a few months?
This usually points to an underlying cause such as substrate movement, a hollow bed, or tiling onto a floor screed that had not fully cured. Simply replacing the tile again without addressing the cause is likely to lead to the same result.
Will a new tile ever match perfectly?
It can be very close if you have an original spare tile, but expect some visible variation if you are sourcing a replacement later, since tile colour and shade vary between manufacturing batches and can fade slightly with age.
Is it worth using a tile chip repair kit instead of replacing the tile?
For a small cosmetic chip on a wall tile, a repair kit can be a reasonable short-term option. For cracks, structural damage, or floor tiles that take foot traffic, replacing the tile properly gives a more durable result.
Do I need a movement joint when replacing just one tile?
Not for a single tile repair in the middle of a floor or wall, but if the crack occurred at a room perimeter or a large expanse with no existing movement joint, it is worth having this looked at, since the same cause could crack the new tile too.