Quick answer
Silicone sealant around a bath or shower typically lasts about 5 years — but reseal as soon as you see it going mouldy, cracked, peeling or shrinking away from the edge. Don’t wait for the calendar; do it sooner if it’s failing, because a bad seal lets water get behind it.
How long should bath and shower silicone last?
As a rule of thumb, a well-applied bead of sanitary silicone around a bath, shower tray or basin will give you around five years of good service. That’s an average, though — not a deadline. In a busy family bathroom used hard every day, or a room that doesn’t ventilate well and stays damp, the seal can give up noticeably sooner; a guest cloakroom that barely gets used might go longer.
So the honest answer isn’t really a number of years — it’s the condition of the silicone. The day it stops doing its job, it’s due, whether that’s year three or year seven.
The warning signs it’s time to reseal
These are the things to look for along the joint where the bath or shower meets the tiles, tray or wall. Spot any of them and the silicone has come to the end of its life.
Mould you can’t clean off
Surface mould wipes away. But once those black or pink stains are inside the silicone and a good clean won’t shift them, the seal is colonised and no amount of scrubbing brings it back — it needs replacing, not cleaning.
Gaps, cracks or shrinking
Over time silicone shrinks and pulls away from the edge, leaving a thin gap or splits along the bead. Any gap, however fine, is an open door for water to track behind.
Peeling or lifting
If you can catch an edge with a fingernail and the silicone lifts or peels away from the surface, it’s lost its grip. A seal that isn’t bonded isn’t sealing anything.
Going hard or discoloured
Fresh sanitary silicone stays slightly flexible so it can move with the bath. When it goes hard and brittle, or yellows and discolours, it’s perished and will crack the next time the bath flexes under weight.
Why a failing seal matters more than it looks
A bit of tired silicone seems cosmetic — but the seal is the only thing stopping bath and shower water finding its way into the structure behind your tiles. Once water gets past it, you can’t see where it goes, and that’s the problem.
Water tracking behind a bad seal soaks the wall boards and can rot the floor joists and the timber under the bath. In an upstairs bathroom it eventually shows up as a stain on the ceiling below — and by then the damage has been building for months. A reseal is a small job; the repair after a leak rarely is. That’s why we’d rather you sort it early.
A seal like this is past cleaning — once mould is in the silicone and the bead is splitting, it needs cutting out and redoing.
Cleaning mouldy silicone vs replacing it
It’s worth knowing the difference, because one buys you time and the other is the only real fix. If the mould is sitting on the surface of an otherwise sound seal, a mould-and-mildew cleaner will often lift it and the silicone is fine to keep. But once the staining is embedded in the silicone, or the bead is cracked, peeling or gapping, cleaning is a lost cause — the only proper answer is to cut it all out and lay a fresh seal.
A quick note on terminology, because people mix them up: grout is the hard cement-like filler between the tiles, and silicone is the flexible seal in the corners and along the bath and tray edges. They’re different materials with different jobs, and they fail differently. If it’s the grout lines giving you grief rather than the seal, our guide on stopping bathroom grout going mouldy is the one you want.
Doing it properly: DIY or done for you
Resealing isn’t complicated, but a tidy, watertight job lives or dies on the prep. The mistake most people make is squirting fresh silicone straight over the old — it won’t bond, and you’ll be back to square one in months. Done right, the steps are simple.
What a proper reseal involves
- Cut out all the old silicone, top and bottom, leaving nothing behind
- Clean and dry the joint fully, and treat any lingering mould
- Lay a quality mould-resistant sanitary silicone in one steady bead
- Tool it neatly so it’s smooth, even and properly pressed into the edge
- Let it cure before the bath or shower goes back into use
Make the seal last longer
The single biggest thing you can do to get the most years out of a seal is keep the room ventilated. Silicone fails fastest where it stays warm and wet, so anything that clears the damp helps.
- Run the extractor fan during and after showers
- Open a window or leave the door ajar to let steam escape
- Wipe the bath and shower edges down after use
- Deal with surface mould early, before it digs into the silicone
Happy to leave it to us? Resealing is exactly the kind of small aftercare job we’ll come back and do — a clean cut-out and a neat new bead in an afternoon. And if you ever think water has already got behind a seal, don’t sit on it: see what to do if something goes wrong.
Common questions about resealing
Can’t I just clean the mould off instead of resealing?
If the mould is only on the surface of a sound, well-stuck seal, a mould cleaner will usually shift it and you’re fine. But once the staining is embedded in the silicone, or the bead is cracked, peeling or gapping, cleaning won’t fix it — the silicone needs cutting out and replacing.
Is resealing a bath the same as redoing the grout?
No. Grout is the hard filler between the tiles; silicone is the flexible seal along the bath, tray and basin edges and in the corners. They’re different materials that fail in different ways, so they’re sorted separately — though it’s common to refresh both at once when a bathroom’s looking tired.
Can I reseal it myself?
You can. The key is to cut out every scrap of old silicone, clean and dry the joint, use a proper mould-resistant sanitary silicone and tool the bead neatly. Don’t apply new over old — it won’t bond. If you’d rather it was done quickly and neatly, it’s a small job we’re glad to come back for.
A small job worth doing
Got a seal that’s seen better days?
If the silicone round your bath or shower is going mouldy, cracking or pulling away, let our Plymouth team cut it out and lay a fresh, watertight bead — before it costs you more than a seal.