6 best bathroom sealants to stop water getting where it shouldn’t
The best bathroom sealants will stop water seeping behind tiles, getting under flooring and stay stain free. Here we round up a selection of highly rated products that will get the job done
1. The list in brief ↴
2. Best overall: UniBond Anti-Mould Sealant
3. Versatile All-rounder: Everbuild Everflex 500
4. Fastest working: Gorilla Mould Resistant Seal
5. Trademan's Choice: Dowsil 785 Sanitary Sealant
6. Best For Mould: Everbuild Anti-Mould Sealant
7. Best For Small Bathrooms: 151 Silicone Sealant
8. How to choose
9. How we test
The best bathroom sealants will make sure that water and moisture won't seep into those gaps around your bath, shower, sink, toilet, or vanity unit. Crucially it will stop water ingress into places where water shouldn’t go.
It will help protect against damp and mould and ensure that your bathroom design ideas are brought to life, especially if you love white. This is the standard colour for sanitaryware and the popular choice for bathroom sealant, meaning it can match with most things. But don’t panic if you don’t love white, you can get clear and colours.
But with so many different products on the market, just where do you start when it comes to selecting the right one for your needs? In this guide we put together a list of the best out there to help make your choice.
The Quick List
Struggling to find the time to hunt down the best bathroom sealant to keep your bathroom looking fresh and mould-free? Take a look at this quick overview of all the sealants on this list, along with handy quick links that allow to you skip down the page to get right into a more detailed review of the particular product that you like the look of.
Best Overall Sealant
This anti-mould sealant offers durable, consistent protection. Ideal for humid areas, it seals quickly, drying in 20 minutes. It includes a sealant gun and resealable cap.
Versatile All-rounder
This anti-mould sealant provides long-lasting protection with a potent fungicide. It dries in stages: skin in 10 minutes, tack-free in an hour, fully dry in 24 hours. It's available in five colours.
Fastest Working Sealant
This sealant dries quickly, being water-ready in 30 minutes. It's mould-resistant, suitable for all surfaces, and has a lifetime guarantee for cracking and shrinking.
Tradesman's Choice
This Dowsil sealant is favoured among plumbers, as it resists mould, combats bacteria including MRSA and E. Coli, and dries within an hour.
Best For Mould
Forever Clear’s sealant features a patented Mould Shield preventing mould, mildew, and bacteria growth. Drying within 15 minutes, it contains an anti-bacterial additive and is effective even in high humidity areas.
Best For Small Bathrooms
The 151 Silicone Sealant is ideal for minor bathroom repairs like tiles. While not as durable as others, it's affordable and easy to apply without a gun. Available in two colours and multi-packs.
The best overall bathroom sealant
1. UniBond Anti-Mould Sealant
Our expert review:
Specifications
Reasons to buy
Reasons to avoid
UniBond’s Anti-Mould sealant should be a top pick for any household – particularly if your primary focus is on ensuring long-lasting protection.
Its high adhesion formula helps to ensure a durable result that will stay consistent throughout application. Once applied, the sealant forms a permanently flexible and waterproof seal, which reduces the chances of any cracks or breakage.
UniBond's anti-mould formula is perfect for use in areas that have high humidity levels, as it quickly seals around baths, toilets and kitchen sinks. Remarkably, it is touch dry in just 20 minutes.
The sealant gun that comes included with the product makes it easy to use, and an integrated resealable cap is handy so you can do little bits at a time without worrying about the product drying out.
A versatile all-rounder
2. Everbuild Everflex 500 Bath & Sanitary Silicone
Specifications
Reasons to buy
Reasons to avoid
This one came really close to taking the title of 'best overall'.
Everbuild's Everflex 500 anti-mould sealant is a great product and performs well across several fronts.
Long-lasting protection? Check. It incorporates a powerful fungicide into the formula, providing long-lasting protection against mould growth.
Dries quickly? Check. A skin will form within 10 minutes after application, then you'll need to wait around an hour for it to be tack free, and roughly 24 hours for it to be completely dry.
Moreover, it is hygiene and sanitary safe – perfect for busy family bathrooms – and is specifically designed to seal and protect areas where maximum hygiene protection is required. It's also available in five different colours.
Fastest drying bathroom sealant
3. Gorilla Glue Mould Resistant Sealant
Specifications
Reasons to buy
Reasons to avoid
One of the best bathroom sealants for quick drying results – once applied, the versatile Gorilla Glue Mould Resistant Sealant is water-ready within 30 minutes, the fastest water-ready dry time on this list.
If you are being plagued by pink mould in showers then you'll be pleased to hear that this is also mould resistant, can be used on all surfaces, and comes with a lifetime guarantee that it will not crack or shrink.
What's more, it comes with a reusable nozzle making it very easy to apply. On the downside, it only comes in 80ml bottles, so you'll need to buy in bulk for larger sealant jobs.
Trademan's choice
4. Dowsil 785 Sanitary Sealant
Specifications
Reasons to buy
Reasons to avoid
This product from Dowsil, formerly known as Dow Corning, has been around for many years, and it remains of the most popular sealants on the market.
The 785 Sanitary Sealant is a leading product which is particularly popular among plumbers. It utilises a fungicide formula that resists mould to keep your bathroom looking and smelling fresh, and it protects against bacteria growth, MRSA, E. Coli and salmonella.
It dries really quickly too – it should be tack free in under one hour.
The best sealant for clearing mould
5. Everbuild Forever Clear Anti-Mould Bathroom Sealant
Specifications
Reasons to buy
Reasons to avoid
The Forever Clear’s patented Mould Shield feature is this sealant's main highlight as it actively prevents the growth of bacteria, mould and mildew. If you are struggling to keep either of these under control, then this one is well worth a look.
It can be touch dry within 15 minutes of application thanks to its high-quality drying formula, plus it includes an anti-bacterial additive which helps to combat against new germs from cropping up. It's also effective in high humidity areas.
The best sealant for small bathrooms
6. 151 Silicone Sealant
Specifications
Reasons to buy
Reasons to avoid
The 151 Silicone Sealant is a good option for small bathroom jobs, such as repairing tiles, where only a little product will be required. Of course, if you need more than this, you will be relieved to learn that it's also available in a handy pack of six.
While it isn't quite as long-lasting as other sealants on this list, it is affordable, easy to apply and includes a screw-on applicator nozzle so you don't need a gun for application. It's also available in two different colour options to suit a variety of bathroom designs.
How to choose the best bathroom sealant
If you don't use a high-quality bathroom sealant you could be inviting moisture problems that will result in bathroom mould and water damage. When buying a sealant, look out for these essential properties:
Anti-mould
A moist bathroom environment can be a breeding ground for mould and mildew. To avoid spending hours removing mould from grout, select a sealant that has anti-mould properties to ensure longevity and maintain a healthy space. A good anti-mould sealant not only prevents unsightly black spots but also reduces the risk of health issues associated with mould spores.
Quick drying time
A sealant with a drying time of under an hour is ideal, ensuring a robust, waterproof barrier in a short timeframe. However, it's crucial to differentiate between 'touch dry' and 'fully cured'. While some sealants may feel dry to touch within minutes, they might take longer to fully set and achieve maximum strength. Always check the manufacturer's instructions for the best results.
FAQs
Can you apply new sealant over old?
You can trust Homebuilding & Renovating.
It is always best to remove any old silicone sealant before applying new. Not only will the existing product probably be dirty (and possibly mouldy, even if you have looked into how to remove black mould from silicon sealant) but it is less likely you will be able to get a good bind between the old and new sealants.
Should a bath be full before you seal around it?
Yes, it might sound odd, but when sealing a bath you should fill it with water before applying sealant. When full of water, most baths sink a little and this could cause sealant to crack as it 'stretches' if you have applied it to an empty bath.
How we test bathroom sealants
There's a lot to consider when selecting the best sealants for your bathroom. Thankfully, the Homebuilding & Renovating team is getting hands-on experience with the products in this buying guide to help you feel confident in choosing the right product for you.
In our ongoing independent reviews we are testing the ease of use and drying time to gauge each product’s efficacy, and assessing key factors including whether it's waterproof and the range of colours it comes in.
Our team is passionate about DIY and home improvement (which probably won’t be a surprise) so we already have detailed knowledge about the brands that make these products.
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Jack has worked in journalism for over a decade and was the former News Editor of Homebuilding & Renovating between 2019 until 2023. In his time as News Editor he broke the most relevant and beneficial stories for self builders, extenders and renovators, including the latest news on the construction materials shortage, planning permission and green initiatives. In 2021 he appeared on BBC's The World at One to discuss the government's planning reforms.
He enjoys testing new tools and gadgets, and having bought his first home in 2013, he has renovated every room and recently finished a garden renovation.
- Steve Jenkins
- Gabriella DysonInteriors journalist and contributing editor