5 Warning Signs Your Shower Silicone Is About to Fail (And Cause a Leak)
Failed silicone is one of the most common causes of hidden bathroom leaks. Spot it early and you avoid the ceiling damage downstairs.
Silicone is the last line of defence between your shower water and the structure of your house. When it fails, water tracks behind the tray and into floors, walls and ceilings — often unseen for weeks.
1. Black mould along the bead. Once mould has taken hold inside the silicone, it's chemically broken down — it won't come back, even with bleach.
2. A lifted edge you can lift with a fingernail. That gap fills with shower water every single use.
3. Hairline gap between silicone and tray. Common after the tray flexes under weight. Water will be tracking already.
4. Discolouration to brown or yellow. Cheap silicone breaking down. Time to strip and reseal.
5. A musty smell in the room below the bathroom. Often the first sign of trapped water in the floor void.
If you spot any of these, the fix is simple: strip the failed bead out fully, prep the area and apply a fresh seal. Never apply new silicone over old — it won't bond and the leak continues.
We reseal shower trays and baths across Essex from £95. WhatsApp a photo and we'll tell you straight whether it needs a full strip or a touch-up.
