Best silicone sealant: Help make your home watertight and airtight
Houses can be prone to damp and damage, but our pick of the best silicone sealants can help keep your home in tip-top condition
Silicone sealant is a simple type of adhesive that’s commonly used to create a water or airtight seal between two surfaces. You might also hear it referred to as silicone gel. The sealant typically has a gel-like consistency when you first apply it, making it easy to fit into gaps. It then cures to a robust, rubber-like texture that’s very durable.
The best silicone sealants make light work of those little DIY tasks. The flexible nature of silicone means results are long-lasting when applied correctly, so you won’t have to touch things up every five minutes.
We’ve got a great selection of options in our round-up, suitable for every budget, while our buying guide below will answer any questions you might have about silicone sealants. So let’s get started.
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Best silicone sealants: At a glance
- Best budget silicone sealant: Wickes All Purpose Silicone Sealant | £5.60
- Best all-rounder: Brewers Paintable Sealant and Adhesive All-in-One | £6.34
- Best sanitary sealant: Dowsil DC785+ Sanitary Silicone Sealant | £9.99
- Best heavy-duty silicone sealant: UniBond Perfect Finish Silicone-Based Sealant | £15
- Best for metal: No Nonsense X8 Hybrid Sealant and Adhesive | £9.99
- Best colour selection: BAL Micromax Anti Mould/Bacteria Sealant | £15
How to choose the best silicone sealant for you
What is silicone sealant?
As we noted in the introduction to this guide, it’s commonly used to create a waterproof, airtight join between two surfaces or angles. As they create a slightly elastic bond once cured, they’re ideal for creating a long-lasting seal that will hold its shape well over time, even in outside areas that are exposed to harsh weather conditions. Because silicone is slightly rubbery once cured, it also provides cushioning between surfaces that are likely to move.
Types of silicone sealant
Silicone sealants typically come in a cartridge or tube, with most sporting a nozzle for precise application. You can choose between a squeezable tube for application by hand, or rigid tubes, which need to be used with a sealant gun. The latter will generally be larger and cover a wider area.
There are two main types of silicone sealant – neutral cure and acid cure (also known as acetoxy).
While acid cure is great for working with surfaces such as glass or glazed tiles, it can be too corrosive for other materials, so be sure to check the manufacturer’s label before using. Neutral cure is generally the safest type of sealant when working with wood, plastics or metal. However, it does take slightly longer to cure.
The majority of silicone sealants tend to be multi-purpose but it’s best to choose a specific sanitary silicone sealant for wet applications, such as in the bathroom, as they’re more resistant to mould and mildew. You’ll also need to check whether a sealant is designed to use indoors, outdoors or both.
How long does silicone sealant take to dry?
This varies between products, depending on the specific materials and compounds used in the product. On average, most sealants will be touch dry in one to three hours. We would, however, recommend waiting at least ten hours (and ideally 24) before letting the seal be exposed to any direct water contact. So if you’re using your silicone sealant outside, choose a dry day, even if it’s suitable for outdoor use.
Tips for using silicone sealant
Use a primer where possible – Primers don’t have a very long shelf life, but they can help improve the adhesion of your sealant.
- Shelf life – Silicone sealants won’t keep forever in their tube as once the sealant is exposed to the elements. Keep nozzles attached at all times and if you live in a hot and humid environment, keep your silicone sealant in the fridge.
- Expiration date – Silicone sealants can undergo changes if they’re out of date, will take longer to dry and won’t be as durable once set. Make sure you check expiration dates before you buy or on tubes already opened.
- Clean surfaces – Clean surfaces thoroughly before using sealant, as residues can prevent a solid bond forming. You should also ensure surfaces are dry before application.
- Use pressure – If you’re sealing two pieces of metal together, you’ll need to apply pressure to ensure the sealant forms a strong bond. We recommend using a vice or clamp to hold the pieces together firmly.
How much should I spend?
We’ve got silicone sealants ranging from £5 to £15 below, all of which are highly effective. In fact, we wouldn’t recommend paying more than this unless you’re buying an extra-large tube.
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The best silicone sealants to buy in 2023
1. BAL Micromax Anti-Mould/Bacteria Sealant: Best colour selection
Price: £15 | Buy now from Amazon
BAL sealants are much loved by professional decorators not only for their excellent adhesive qualities, but also for the huge range of colours available. With so much choice, it’s easy to match one to your existing colour scheme.
The sealants can be used on a range of surfaces including acrylic, ceramic, fibreglass, glass, glazed and more. They’re also suitable for use in both indoor and outdoor environments, dry and wet areas, are unaffected by weather, UV radiation or water immersion, help inhibit growth of bacteria and are sanitary for use in food consumption areas. The only negative we found is that they take a while to dry, approximately 24 hours per 3mm thickness. If you’re not in a hurry, though, this is an excellent choice for the colour conscious.
Key details – Size: 310ml; Colours: Gunmetal, white, brooklyn, smoke, ash, antique white, ebony, praline, cedar, graphite, jasmine, lime, pecan, cement, coffee, cream; Suitable for: All-purpose; Application method: Sealant gun
2. Wickes All Purpose Silicone Sealant: Best budget silicone sealant
Price: £5.60 | Buy now from Wickes
Wickes’ All Purpose Sealant is extremely well priced and comes in a choice of clear, white, black, brown or grey – we tested the clear variety. Application is via a cartridge gun and offers coverage of 11m using a 6m bead. The silicone sealant is suitable for both interior and exterior use and is also waterproof and mould-resistant. It’s easy to apply and provides excellent adhesion, while drying to a nice, flexible finish. We also really liked the screw-on cap for this sealant, which helped keep it usable for longer.
It has a slightly stronger smell than some other silicone sealants, so you may want to consider using an adequate mask if you’re sensitive to chemical smells. It’s also not the quickest to dry, taking a full 24 hours to cure completely. Despite this, it’s still a good silicone sealant at a very reasonable price.
Key details – Size: 300ml; Colours: Clear, white, black, brown and grey; Suitable for: All-purpose; Application method: Cartridge gun
3. Brewers Paintable Sealant and Adhesive All-in-One: Best all-rounder
Price: £6.34 | Buy now from Brewers
Brewers’ sealant is our top all-rounder choice because there aren’t any surfaces it can’t safely be used on. What’s more, as it’s a combined sealant and adhesive, it has even more uses and eliminates the need for multiple products.
It’s suitable for indoor and outdoor use, sealing joints around sanitary fixtures and can be used on perimeter joints around window and door frames too. You can use it for glueing panels, skirting boards, thresholds and insulation materials. It can also be used to seal and bond glass, porcelain, coated metal, epoxy and polyester panels, covered polystyrene, PVCu, stainless steel, anodised aluminium and finished wood. Phew.
What we particularly like about the Brewers sealant though, is how well it works even on damp surfaces. It’s also mould resistant and safe to use in food preparation areas. The sealant only comes in white, though and while it is paintable, we’d like to see it in a wider range of colours – or at least a clear version.
Key details – Size: 290ml; Colours: White; Suitable for: All-purpose; Application method: Nozzle
4. Dowsil DC785+ Sanitary Silicone Sealant: Best sanitary sealant
Price: £9.99 | Buy now from Toolstation
This is one of the best sanitary silicone sealants you can buy. It dries incredibly quickly and is tack-free within an hour, provides added protection against mildew and bacteria growth and is designed to be used on non-porous surfaces (such as those you’d find in a bathroom). In testing, we found this to be a particularly strong adhesive that provides a tough and durable finish. It’s one of the pricier options on our list, but the quality is excellent and it’s easy to use without creating masses of mess.
The only small downside is that because it’s such a good adhesive, it can take a little extra scrubbing to get off your hands, should you get any on them. We tested the white sealant which has a lovely, bright colour and while we can’t comment on the long-term look of the sealant, customer reviews suggest it maintains its colour particularly well.
Key details – Size: 310ml; Colours: Clear, white and Manhattan grey; Suitable for: All-purpose; Application method: Sealant gun
5. UniBond Perfect Finish Silicone Based General Purpose Sealant: Best heavy-duty sealant
Price: £15 | Buy now from B&Q
The UniBond Perfect Finish sealants are tough – so tough, in fact, they come with a 35-year guarantee. They’re ideal for a variety of jobs and will seal, fill and even insulate the most common construction joints around your home. The waterproof and flexible sealant is mould resistant with very little odour and will be touch-dry in 20 minutes. We tested the clear (translucent) sealant and were impressed by how well it blended into its surroundings.
Even better, the UniBond sealants don’t need a primer, saving valuable time. You can use them on substrates including glass, tiles, ceramics, anodised or pure aluminium, steel, stainless steel, painted and virgin wood, polyester, PC, PVC, clinker brick (both glazed and unglazed), concrete and other porous substrates. Although one of our more expensive choices, its long-lasting, tough finish makes it worth the price.
Key details – Size: 300ml; Colours: Clear, white, black and grey; Suitable for: All-purpose; Application method: Sealant gun
6. No Nonsense X8 Hybrid Sealant and Adhesive: Best for metal
Price: £9.99 | Buy now from Screwfix
The No Nonsense range of hybrid sealants and adhesives are all-purpose products that work on a variety of substrates without the need for primer or any additional fixings. However, we were particularly impressed with its performance on metal. You can use the sealant on all types of metal, even lead, and it provides a strong finish. Beyond this, you can also use the sealant on a number of other surfaces, with it being ideal for sanitary areas, general purpose jobs, construction, frame and glazing, gap filling, roof and guttering and grab adhesion.
One thing to note is that this is a sealant that takes time to fully cure – around 24 hours for a 2/3mm bead. So if you put a thick bead down, it could take several days to fully cure. The hard-wearing finish is worth the extra time though and the sealant dries with an attractive gloss finish.
Key details – Size: 290ml; Colours: Clear, white, black and grey; Suitable for: All-purpose; Application method: Sealant gun
