Guide
Which silicone should go in a bathroom, and does the type matter?
There are about forty tubes on the shelf and roughly three decisions inside them. This is what the three are, and why the cheapest tube is the expensive one.
Nothing here is a product recommendation. It is the properties to look for on the back of the tube, which is more useful, because what is on the shelf changes and the chemistry does not.
Sanitary grade, not general purpose
A sanitary silicone has a fungicide in the cured film. A general purpose one does not. In a room that holds warm moisture for an hour a day, that difference decides whether the joint goes grey in a year or stays white for several.
The fungicide is not permanent. It is consumed slowly, which is one reason no sealant lasts forever and why nobody serious offers a guarantee on a bathroom joint. It buys years rather than decades, and it is the single most useful thing on the label.
The word to look for is sanitary or mould resistant on the front, and a stated fungicide on the back. If neither is there, it is a general purpose tube in a bathroom colour.
Acetoxy or neutral cure
Acetoxy silicone is the one that smells strongly of vinegar as it cures. It grips glazed ceramic, glass and most sanitary acrylic well, and it is what belongs on an ordinary tiled bath or shower. Most bath manufacturers state a sealant type in their fitting instructions, and where they do, that instruction outranks anything on this page.
Neutral cure silicone smells of very little. It is slower and it costs more, and it is what belongs anywhere acetic acid would cause a problem: natural stone, which it can stain, marble and some composite worktops, mirrors, and metals that corrode. On stone specifically, neutral cure alone is not the whole answer: some neutral products still leach oils into a porous stone and leave a shadow, so the tube has to say it is suitable for natural stone rather than simply saying neutral cure.
Getting this wrong on a stone worktop or a marble splashback shows up as a permanent dark edge along the joint, and it does not come out. If the surface is stone, or you are not sure whether it is stone, use neutral cure.
White or clear, and where each one wins
White is more forgiving. It hides a slightly uneven line and it matches most baths and trays, which is why the majority of bathroom joints are white.
Clear is better where the two surfaces either side of the joint are different colours, on a dark tile, or against a stone worktop, because a white line there draws the eye to itself. It is less forgiving of a poor bead, because you can see the substrate through it, and it can look slightly grey once it cures in a deep joint.
Coloured and grey silicone exists for matching grout lines. It is worth it when the joint runs against grout of the same colour and rarely otherwise.
The things on the tube that do not matter much
A large number on the front claiming a number of years is a marketing figure. Every silicone in a wet room is at the mercy of ventilation, how often the joint is dried, and whether the substrate was clean when it went on. Those three do more than the brand does.
Rapid cure formulations set faster but are not stronger, and they give you less time to tool the bead, which is where most home attempts go wrong. The extra minutes are worth more than the saved hours.
One thing that does matter, and is never on the front: the tube date. Silicone has a shelf life, usually somewhere between twelve and eighteen months, and an old tube skins in the nozzle and cures unevenly. Check the stamp before you buy.
Also asked
Related questions
Is there a silicone that never goes mouldy?
No. A sanitary grade with a fungicide resists it for years rather than months, and drying the joint after a shower does more than any product on the shelf. Anything sold as permanently mould proof is selling the fungicide as though it were forever.
What silicone do you use?
A sanitary grade with a fungicide, acetoxy on tile and acrylic, and a stone safe neutral cure on stone or a composite worktop, in white or clear as the room needs. It is in the price rather than added as a materials line. Where a bath, tray or worktop maker specifies something in particular, we use theirs.
Can I use bath sealant on a kitchen worktop?
On a laminate worktop against a tiled upstand, yes. On granite, quartz, marble or any natural stone, use a product whose own label says it is suitable for natural stone. Neutral cure is the starting point, because acetoxy silicone can leave a permanent stain along the edge of a porous stone, but not every neutral cure product is stone safe.
If you would rather not
The job this article describes, done for a published price
The pages this covers
- Kitchen sealant and worktop sealing
Worktop to wall joints, upstands, splashbacks and the run round an inset sink, sealed with the old line taken out first. £95 on its own.
- Bath resealing
The old sealant round the bath stripped out completely, the joint cleaned back and dried, and a fresh sanitary bead run and tooled. £95 including VAT and silicone.
The other guides
- Can you reseal a bath or shower without removing the old silicone?
The short answer is no. The longer answer is about what silicone bonds to, and what is living inside the joint you would be covering up.
- Why does bathroom sealant go mouldy, and can it be stopped?
It grows inside the silicone, feeding on soap residue in a joint that never fully dries. What actually slows it down, and what makes no difference.
- How long does silicone take to dry, and when can you use the bath?
Touch dry in under an hour, usable after twenty four. Why those are two different numbers, and what happens if you do not wait.
- Why does bathroom sealant leak, and is the sealant even the problem?
Water on the floor below a bathroom has three usual causes and only one of them is the sealant. Here is how to tell which one you have before you pay for the wrong repair.
- How often should bathroom sealant be replaced?
There is no fixed interval. There are four signs, and a family bathroom gets through a joint considerably faster than a spare one does.
Get a price
Book a reseal with Exeter Silicone Services
Send a photograph of the joint and say which fittings need doing. Back comes the price off the published card and the next free slot. Ringing is quicker if you want a date fixed today.
- Bath or shower
- £95
- Both on one visit
- £150
- Whole bathroom
- £185
VAT and silicone included. Minimum charge £95.