Why has my bathroom sink cracked?
A bathroom sink can crack after an impact, a sudden temperature change, movement in the unit or stress around a fitting. A fine surface mark may only affect the glaze, but a deeper crack can leak or weaken the basin.
What causes a bathroom sink to crack?
A dropped bottle or other hard object is a common cause. Very hot water poured into a cold ceramic basin can also create thermal shock, especially if the basin already has a small chip or flaw.
Cracks can develop when a wall-hung basin, worktop or vanity unit moves, or when tap and waste fittings have been overtightened. If a crack begins around a fixing hole or the basin has shifted, its support should be checked as well as the visible damage.
Is it safe to keep using a cracked sink?
Stop using the sink if the crack passes through the bowl, is growing, feels sharp, or allows water underneath. Put a container below if it is safe to do so, keep the cupboard dry and isolate the tap supplies if water is escaping continuously.
A hairline mark in the glaze may not leak, but it can trap dirt and become more noticeable. Dry the basin and watch whether the line changes after use. Do not lean on or load a cracked basin while its condition is uncertain.
Can a cracked ceramic sink be repaired?
Small cosmetic chips can sometimes be improved with a suitable repair product, although the colour and finish may not match perfectly. A structural crack through the bowl or around a fixing is usually more reliably dealt with by replacing the basin.
Sealant applied over a crack is not a dependable structural repair. It may hide the route of a leak without restoring the strength of the ceramic. A fitter can assess the basin, its support and the surrounding worktop or unit before recommending replacement.
How can I prevent another crack?
Avoid pouring boiling water directly into a cold basin and keep heavy glass containers where they are less likely to fall. Make sure wall fixings, brackets and vanity units remain firm, and have movement investigated rather than simply resealing around it.
When replacing a basin, the tap, waste and fixing nuts should be fitted evenly and without excessive force. Correct support matters because ceramic is strong in normal use but can fail where it is placed under concentrated stress.
Quick cracked sink checklist
- Dry the sink and check whether the crack passes through the bowl.
- Look underneath for drips, dampness or swelling in the vanity unit.
- Stop using the sink if the crack leaks, grows or has sharp edges.
- Do not rely on sealant to repair a structural crack.
- Check for movement in the basin, worktop or supporting unit.
- Ask a bathroom fitter to assess significant damage and safe replacement.