The silicone sealant around a bath or shower does an important job. It stops water getting behind the bath, under the tray and into walls and ceilings. When it turns black, cracks or peels away, it’s not just a cosmetic problem: it’s often the first sign water is getting where it shouldn’t.
Why sealant fails
- Mould: constant damp and poor ventilation let mould grow into the silicone, and once it’s inside, cleaning won’t remove it
- Movement: baths flex when filled and stood in, so sealant applied to an empty bath can tear
- Poor preparation: silicone over old sealant, soap residue or damp surfaces won’t bond properly
- Age: even good sealant breaks down over time
The signs of a hidden leak
Look out for:
- staining or bubbling paint on the ceiling below the bathroom
- loose or hollow-sounding tiles around the bath or shower
- grout that keeps cracking or going dark
- a musty smell, or flooring that’s soft or lifting near the bath
- water marks on the side panel or skirting
If you spot any of these, get it looked at quickly. Water damage spreads, and a reseal is far cheaper than a new ceiling.
How a proper reseal is done
- Remove all old sealant completely, with every trace cut and scraped away. New silicone over old never lasts.
- Clean and treat the joint to remove soap residue and mould spores.
- Let it dry fully. Sealing a damp joint traps moisture and mould.
- Fill the bath with water before sealing, so it sits at its loaded position and the sealant isn’t torn when it’s used.
- Apply a quality sanitary silicone with a mould inhibitor, tooled to a neat, continuous bead.
- Leave it to cure for the full time recommended before using the bath or shower.
Stopping it coming back
- run the extractor fan during and after every shower (see our extractor fan guide)
- squeegee or wipe down the sealant after use
- keep shower screens and trays clean of soap build-up
For landlords and agents
Resealing is one of the most valuable jobs at a change of tenancy. It makes the bathroom look fresh for viewings and protects against leaks. It’s on our void property checklist, and we can combine it with grout repairs, tap washers and other small jobs in one visit. See our property maintenance service.
We cover London and Essex, with our own engineers working every day across Chigwell, Loughton, Buckhurst Hill, Woodford, Ilford, Romford, Brentwood and Epping. Call 020 8227 0035 or request a quote.