The Best Bathroom Sealants For A Watertight And Fresh Finish
Flexible mould-resistant silicones we'd trust around the bath and shower tray.
Our quick verdict
Our pick of the best bathroom sealant is the UniBond Anti-Mould Silicone Sealant, a silicone made for steamy rooms that's very easy to run neatly from a gun, which matters if you only reseal a bath now and then, and its resealable cap keeps the rest of the cartridge for next time. For long runs where the cost adds up, the Everflex 500 Bath & Sanitary Silicone is cheaper and comes in grey and ivory.
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Our Picks At A Glance
- Check price of UniBond Anti-Mould Silicone Sealant
Best Overall
UniBond Anti-Mould Silicone SealantSealing baths and showers in a warm and steamy bathroom
- Check price of Everflex 500 Bath & Sanitary Silicone
Best Value
Everflex 500 Bath & Sanitary SiliconeBigger sealing jobs on a budget or bathrooms needing a grey or sand colour
- Check price of Dow Corning Dowsil Bathroom Sealant
Best All-Rounder
Dow Corning Dowsil Bathroom SealantKitchens and bathrooms where hygiene matters as much as a clean finish
- Check price of Everbuild Forever Clear Sealant
Best Anti-Mould
Everbuild Forever Clear SealantShowers and windowless bathrooms where mould keeps coming back
- Check price of Gorilla Glue Mould Resistant Sealant
Best Quality Finish
Gorilla Glue Mould Resistant SealantSealing jobs that need to be back in use within the hour
- Check price of 151 Bathroom Silicone Sealant
Best For Small Jobs
151 Bathroom Silicone SealantQuick repairs and short joints without buying a sealant gun
Most sealant failures come down to the job rather than the tube. Fresh silicone won't grip the remains of an old bead, and a bath sealed while empty drags the joint apart as soon as it's filled. With the prep right, the choice narrows to how much mould protection the room needs, which colour suits your tiles and tray, and how much you're sealing. If the joint keeps splitting because the tray flexes, new sealant won't cure it, and our guide to the best shower trays is worth a look.
A short repair doesn't justify a cartridge and gun, while a whole bathroom gets through small tubes fast. We've lined up six options, from a squeeze tube to full-size cartridges.
How We Tested These Bathroom Sealants
Between our rentals and Airbnbs, there's always a tired seal to replace or a new fitting to seal in. Most of that work is in bathrooms, around baths, shower trays and toilets, but we also use sealant on tiling, window frames and kitchen worktops, so we've tried a long list of silicones from the big UK brands.
The photo below shows a bath we sealed recently, with the finished bead running along the joint between the bath and the tiles.
We also filmed the Short below while sealing a bath, which shows how a quality sealant behaves as it comes out of the gun and gets smoothed into the joint. The full method is in our step-by-step guide on how to seal a bath.
Sealing Bath, Shower & Other Fittings Is Much Easier With A Quality Sealant & We've Tested Multiple!
Each sealant was weighed up on these points:
- Application: How smoothly it flows from the nozzle and how easy it is to tool
- Mould resistance: Whether it contains a fungicide and what the brand claims for it
- Drying and curing: How soon it's touch dry and when the bath or shower can be used
- Colours and sizes: The finishes on offer and whether there's a small tube for repairs
- Standards: Any certifications the brand quotes
- Value: What you get for the money against the others here
Drying times, standards and mould claims come from each manufacturer, and the product write-ups make that clear.
Our Pick Of The Best Bathroom Sealants
Five of these come in cartridges for a standard sealant gun, and the last is a small squeeze tube for jobs that don't need one.
Best Overall
UniBond Anti-Mould Silicone Sealant
Best for: Sealing baths and showers in a warm and steamy bathroom
Check Price On AmazonUniBond made this silicone for warm, humid rooms, and it's the one we'd reach for first around a bath or shower. It's very easy to use with a sealant gun, which makes it a good choice if sealing isn't a job you do regularly.
The formula stays flexible once cured, so it moves with a bath as it fills and empties, and it's waterproof and mould resistant. UniBond says it suits tiled areas, kitchens and worktops as well as bathrooms. It comes in white or ivory in a 300 ml cartridge with a resealable cap, so a half-used tube is still usable for the next job, and it's fully dry in 24 hours. It costs more than the Everflex.
What we like
- Very easy to use with a sealant gun
- Made for warm and humid rooms
- Permanently flexible and mould resistant
- Resealable cap on the 300 ml cartridge
- Fully dry in 24 hours
- Cleans with soapy water
What to know
- Dearer than the Everflex 500
- Only white or ivory
Our verdict
For a first-time sealer facing a bath or shower that gets used every day, UniBond Anti-Mould is the easiest one to get right. It's forgiving from the gun and moves with the bath instead of cracking away from it, and a half-used cartridge keeps for the next job. The only real mark against it is the price, so for sealing several bathrooms the Everflex 500 Bath & Sanitary Silicone works out cheaper.
Best Value
Everflex 500 Bath & Sanitary Silicone
Best for: Bigger sealing jobs on a budget or bathrooms needing a grey or sand colour
Check Price On AmazonEverflex 500 is the silicone to buy when you've a lot of joints to seal. It's an anti-fungal sanitary sealant for showers, baths, basins and tiles that costs noticeably less than UniBond, and Everflex says it's certified to the European standard EN 15651 for sealants. It stays flexible, cures quickly and is made to stop mould building up on the bead.
Colour choice is a strength, with clear, grey, ivory and sandstorm, which helps when white silicone would stand out against coloured tiles or a dark tray. The drawback is the lack of a resealable cap, so once a cartridge is opened, plan to use it up rather than saving it for months.
What we like
- Clear, grey, ivory and sandstorm finishes
- Certified to EN 15651 according to Everflex
- Permanently flexible
- Fast curing formula
- Anti-fungal to stop mould building up
What to know
- No resealable cap, so an opened cartridge won't keep
Our verdict
Price and colour are where Everflex 500 pulls ahead. Sealing several bathrooms or a long run of tiles adds up quickly, and the lower cost makes a real difference there. The grey, ivory and sandstorm shades also help it blend with darker grout. Plan to use a cartridge in one go, though, as without a resealable cap an opened tube won't keep, which is where UniBond has the edge.
Best All-Rounder
Dow Corning Dowsil Bathroom Sealant
Best for: Kitchens and bathrooms where hygiene matters as much as a clean finish
Check Price On AmazonDowsil from Dow Corning is the hygiene pick, made to resist bacteria as well as mould, with a fungicide in the formula. Dow has tested it against bacterial growth including MRSA, E. coli and salmonella, and says it conforms to ISO 22196:2007 and ISO 11600-F-20LM.
It's tack free in an hour, so it doesn't stay sticky for long, and it's made for bathrooms, kitchens and sanitary fittings in homes and commercial buildings alike. That makes it a good fit if you're sealing a kitchen worktop and a bathroom in the same week and want one product for both. The only colour is white.
What we like
- Tack free in one hour
- Fungicide in the formula to resist mould
- Suits bathrooms, kitchens and sanitary fittings
- Conforms to ISO 22196 and ISO 11600 according to Dow
- Rated for domestic and commercial use
What to know
- Only available in white
Our verdict
One tube for the kitchen and the bathroom is the appeal of Dowsil. Dow's bacterial testing gives it more hygiene credentials than the others list, which counts on a kitchen worktop as much as round a bath. White is the only colour, though, so around grey or ivory fittings the Everflex 500 Bath & Sanitary Silicone is the better match.
Best Anti-Mould
Everbuild Forever Clear Sealant
Best for: Showers and windowless bathrooms where mould keeps coming back
Check Price On AmazonForever Clear contains Everbuild's patented Mould Shield, which is designed to stop mould and mildew growing on the bead. Everbuild says that, applied correctly, it'll stay free of mould growth for up to 10 years, which is a strong claim for a bathroom sealant.
It forms a permanent waterproof, flexible seal that Everbuild says is touch dry in 15 minutes, and it comes in clear, white, grey and ivory for use indoors or out. A small 80 ml tube sits alongside the 295 ml cartridge, which saves wasting most of a big tube on a short run around a basin. It's relatively expensive for a sealant.
What we like
- Mould Shield formula to stop growth
- Touch dry in 15 minutes according to Everbuild
- Clear, white, grey and ivory
- 80 ml tube for small repairs as well as a 295 ml cartridge
- Works indoors and outdoors
What to know
- Relatively expensive next to the Everflex 500
Our verdict
Bathrooms where the sealant turns black however regularly it's cleaned are the ones Forever Clear is made for. Everbuild's 10 year Mould Shield claim is the strongest in this list, and the 80 ml tube means you can redo one short joint without wasting a full cartridge. It costs more than the Everflex, but in a shower that's fighting mould, that's money well spent.
Best Quality Finish
Gorilla Glue Mould Resistant Sealant
Best for: Sealing jobs that need to be back in use within the hour
Check Price On AmazonGorilla's mould resistant sealant is an all-purpose silicone for shower trays, baths and sinks, and it also works outdoors. Its standout feature is speed, as Gorilla says it's water-ready in 30 minutes, which helps when a household only has one shower.
The brand also says it won't yellow, shrink or crack, and it backs that with a lifetime guarantee. You can buy it in a squeeze tube or a gun cartridge, so it suits small touch-ups and full reseals. It's the most expensive sealant in this roundup, so it makes most sense when a quick return to use or a long guarantee matters to you.
What we like
- Water-ready in 30 minutes according to Gorilla
- Lifetime guarantee
- Resists mould and mildew
- Claimed not to yellow, shrink or crack
- Squeeze tube or cartridge versions
- Suitable indoors and outdoors
What to know
- Most expensive sealant in this roundup
Our verdict
Buy the Gorilla when the shower can't be out of action for long, as in a home with one shower and a queue of people waiting to use it. The lifetime guarantee goes some way to justifying the price. It's the most expensive sealant here, so where the bathroom can sit unused overnight, UniBond Anti-Mould does the job for less.
Best For Small Jobs
151 Bathroom Silicone Sealant
Best for: Quick repairs and short joints without buying a sealant gun
Check Price On AmazonFor a small repair, buying a full cartridge and a sealant gun is overkill, and the 151 squeeze tube gets round that. The 70 g tube has a screw-on applicator nozzle, so you squeeze the silicone straight into the joint without a gun.
It's fully waterproof and comes in clear or white, and it's made for warm and humid rooms. That makes it handy for touching up a short stretch of failed seal, filling a gap around a basin or sealing round the edge of a bathroom extractor fan grille. The 70 g size is the only option, so it isn't the one for resealing a whole bath.
What we like
- No sealant gun needed
- Screw-on applicator nozzle
- Fully waterproof formula
- Clear or white finish
- Small tube means little waste on short joints
What to know
- Only sold as a 70 g tube, which won't stretch to a full bath
Our verdict
With no gun needed, the 151 tube is the one to keep in a drawer for a quick patch around a basin, a tile edge or a fan grille. The 70 g size runs out long before a full bath is done, though, so keep it for small repairs and buy a cartridge such as the UniBond Anti-Mould Silicone Sealant for bigger reseals.
What Makes A Good Bathroom Sealant
Sealant is the finishing touch on a bathroom, and it has to stay waterproof and flexible for years while being splashed, steamed and scrubbed. These are the things to look at before buying a tube.
Silicone Or Decorators Caulk
Decorators caulk is great for gaps around skirting, ceilings and trim because you can paint over it, but it isn't fully water resistant, so it has no place around a bath or shower. Silicone sealant forms a proper waterproof barrier, which is why every product in this list is silicone based.
The flip side is that silicone repels paint. Seal around the bath, basin and shower with silicone, then use a moisture-resistant bathroom paint on the walls and ceiling, keeping the paint off the bead.
Mould Resistance
Look for a sealant that says sanitary, anti-mould or anti-fungal on the tube, as these contain a fungicide that slows mould growth. Bathrooms that stay damp for long periods need the strongest protection, and that's where formulas like Everbuild's Mould Shield earn their price. Good ventilation does just as much, so a working extractor fan protects the bead as well as the walls.
Drying Time And Colours
Most bathroom sealants need around 24 hours to cure fully before the bath or shower is used, although some are quicker. Everbuild quotes touch dry in 15 minutes, Dowsil is tack free in an hour and Gorilla says its sealant is water-ready in 30 minutes. Always go by the time on the tube.
White, clear, ivory and grey cover most bathrooms. Clear suits coloured tiles or glass shower screens, while grey and sand shades blend in with darker grout and trays.
Getting A Neat Bead
Preparation decides how well any sealant lasts. Cut out the old seal completely, as fresh silicone won't stick to it, and our guide on removing old bathroom sealant covers the tools for the job. Clean the joint and let it dry fully, then wipe it with white spirit on a cloth if there's any grease left.
Loading the gun takes a few steps:
- Press the release at the back of the gun and pull the plunger all the way back.
- Drop the cartridge in and push the plunger up to meet it.
- Cut the tip of the cartridge and push a nail through to pierce the inner seal.
- Screw on the nozzle and cut it at a 45-degree angle to match the width of the joint.
Start in a corner and run along the joint in one smooth movement. When sealing a bath, fill it with water first so it settles to its loaded position, and leave the water in until the sealant has cured.
Keeping Sealant Clean
Soap scum and body oils left on silicone feed mould, so give the bead a regular wipe with a bathroom cleaner and dry it after showers where you can. If black spots appear, a mould remover that works on silicone can clear surface growth. Mould that has grown into the sealant can't be cleaned out, and the only fix is to cut it out and reseal.
Common Bathroom Sealant Questions
How long does bathroom sealant take to dry?
Most bathroom silicone sealants are touch dry within 15 minutes to an hour and fully cured in around 24 hours, depending on the brand, the thickness of the bead and how warm and ventilated the room is. Leave the bath or shower unused until the time on the tube has passed, as water on uncured silicone can spoil the seal.
Can you paint over bathroom silicone sealant?
No, standard bathroom silicone can't be painted, because the paint won't bond to its water-repelling surface and will peel or bead up. If you need a painted finish around trim, use decorators caulk instead, but keep silicone for anywhere that gets wet. Choose a silicone colour that matches the fitting, such as white, clear, ivory or grey.
When should you replace bathroom sealant?
Replace bathroom sealant when it starts to peel, crack, come away from the bath or tiles, or shows mould that won't clean off. How long that takes depends on the product, how well it was applied and how damp the room stays. Good preparation, a quality anti-mould silicone and decent ventilation all help a bead last longer.
Why does my bath sealant keep cracking?
Bath sealant cracks when the bath moves more than the bead can handle, and sealing the bath while it was empty is a common cause. Fill the bath with water before resealing so the joint is at its widest, and keep the water in while the silicone cures. Our guide on getting rid of mould helps if the old joint is mouldy too.
Is UniBond Anti-Mould worth paying more for than the Everflex 500?
UniBond Anti-Mould is worth it if you want the easiest one to get right, as it's made for warm, steamy rooms and has a resealable cap, so the rest of the cartridge stays usable. Everflex 500 costs noticeably less and comes in clear, grey, ivory and sandstorm, so it suits bigger jobs or coloured grout, as long as you use the cartridge in one go.
Which of these sealants would you buy for a small repair?
The 151 Bathroom Silicone Sealant is the one for a short patch. Its 70 g tube has a screw-on applicator nozzle, so you don't need a sealant gun. If you want a mould-resistant formula in a small size, Everbuild Forever Clear also comes in an 80 ml tube alongside its 295 ml cartridge.
Is Everbuild Forever Clear worth the extra cost in a shower?
In a shower that keeps going mouldy, yes. Everbuild says its Mould Shield formula stays free of mould growth for up to 10 years when applied correctly, the strongest claim in the roundup. It costs more than the Everflex 500, so in a well ventilated bathroom that stays dry, a cheaper anti-mould silicone does the job.
What do I do if the bath can't sit unused for 24 hours after sealing?
Look at the Gorilla Glue Mould Resistant Sealant, which Gorilla says is water-ready in 30 minutes. It's the most expensive sealant in the roundup, so it makes sense only where a quick return to use matters. With any other silicone, go by the time on the tube, since water on uncured sealant can spoil the seal.
Our Choice Of Bathroom Sealant
UniBond Anti-Mould Silicone is the sealant we'd use for most baths and showers, as it's easy to run from a gun, stays flexible and has a resealable cap for the next job. Everflex 500 is the cheaper alternative with a wider choice of colours.
For a shower that keeps going mouldy, Everbuild Forever Clear is worth the extra, and the 151 squeeze tube covers quick repairs when you don't have a sealant gun to hand.
Richard has spent years renovating properties and turning them into rentals and Airbnbs. Like a lot of people he started out as a beginner, and these days there isn't much DIY he won't take on.