10 Best External Window Sealant in The UK

Last updated on 28/06/2025

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Best Choice

9.8

Exceptional

Everbuild

12X Everbuild White External & Internal Acrylic Frame Sealant - 310ml

Why We Love It

Generous 310ml size. Convenient 12-tube box. Sleek white color.

Main Highlights

Size 310ml.
12 tubes per box.
Colour white.

Unibond Outdoor Extreme Repair - Translucent 294g

Free Shipping

Why We Love It

Highly durable and resilient.
Ideal for all weather.
Superior wet surface adhesion.

Main Highlights

Bonding & Sealing - This premium polymer-based sealant is suitable for bonding and sealing joints indoors and outdoors. Ideal for windows, doors, and facades
Durable - This waterproof and weather-resistant joint sealant cures in approximately 24 hours. Suitable for indoor and outdoor use achieving long-lasting results
Wet surface adhesion - When fully cured, this polymeric sealant is highly resilient and it provides stronger adhesion to a wide range of damp and wet surfaces than silicone sealants
Polymer technology - Thanks to unique technology, the joint filler is impact and shock-resistant for the toughest repair jobs, and will not shrink over time

4x Bond It Rosewood WP70 Neutral Cure Silicone Sealant for External Wood, Aluminium and uPVC Door and Window Frames

Why We Love It

Flexible and weathertight.
Non-fading and Low odour.
Certified Low Meko.

Main Highlights

Flexible and weathertight
Non-fading and Low odour
Neutral cure silicone
Certified Low Meko
Conforms to ISO 11600-F&G-25LM

Everbuild 5 X EXTBR 310ml External Frame Acrylic Sealant - Brown

Main Highlights

SEE Product Description for All Detailes

Everbuild Everflex 450 Premium+ Builders Silicone Sealant – Waterproof Seal – Suits Most Building Materials – Internal and External Use – White – 300ml

Why We Love It

Versatile for many substrates.
High UV stability.
Available in various colors.

Main Highlights

MULTI-PURPOSE – This strong, neutral cure low modulus sealant is ideal for use on expansion joints. It's perfect for internal and external perimeter pointing around PVCu, wood and other window frames.
VERSATILE – Adheres and seals to most substrates including glass, metals, plastic, and wood. It's compatible with polycarbonate, acrylic and lead and has low dirt pick-up for work with PVCu.
HIGH RESISTANCE – High resistance to plasticiser migration. Suitable for use over water-based and solvent-based paints.
FLEXIBLE – Ideal as an expansion joint sealant with a +/- 25% flexibility factor, certified for façade, glazing, cold climate and sanitary applications.
WATERPROOF – Forms a permanent waterproof seal for parapets and roofs and joint sealing to pre-formed panels with excellent UV stability. It provides general glazing, sealing and draughtproofing.
RANGE OF COLOURS – Also available in buff, black, grey, oak, translucent, and brown.

EVO-STIK Window & Door Frame Sealant, Waterproof, Flexible, Overpaintable, Lasts up to 15 Years, Colour: White, Size: 290ml

11% OffFree Shipping

Why We Love It

Weatherproof and reliable protection.
Excellent adhesion to surfaces.
Mould-resistant and overpaintable.

Main Highlights

EVO-STIK Window & Door Frame Sealant, Filled acrylic emulsion paste ideal for sealing around door and window frames
Weatherproof: prevents damage caused by penetration of water and keeps out draughts
Excellent adhesion to most materials including wood, uPVC and metal, For interior and exterior use
Lasts up to 15 years, Contains fungicide to combat unsightly mould growth, Overpaintable when dry
Contents: 1x EVO-STIK Window & Door Frame Sealant, Waterproof, Mould-Resistant, Flexible, Overpaintable, Colour: White, Size: 290ml

Everbuild 3 X EXTBR 310ml External Frame Acrylic Sealant - Brown

Why We Love It

Permanently flexible and long-lasting. Mould resistant for durability. Over paint for match.

Main Highlights

Suitable for internal and external use around window and door frames (Internal only on PVCu)
Provides a permanently flexible, long lasting, mould resistant seal
Also suitable to be used to seal cracks and gaps in brickwork, stone and concret
Once cured the sealant can be over painted if required with most paints
Sika Group was established in 1927 and produces and markets a wide range of state-of-the-art systems covering construction products, industrial manufacturing, automotive manufacturing and DIY products ranges

Everbuild – Everflex – 225 Contract Industrial & Glazing Silicone – Industrial and Glazing Sealant – Adheres to Most Common Building Materials – Transparent – 295ml

13% OffFree Shipping

Why We Love It

Permanently flexible and weather-tight.
Powerful anti-mould properties included.
Versatile for various materials.

Main Highlights

BUILDER GRADE – Everbuild Everflex 225 Contract Industrial & Glazing Silicone is permanently flexible for a weather-tight, temperature-resistant seal up to 200˚C.
ANTI-MOULD PROPERTIES – Contains a powerful anti-fungal compound to prevent mould growth and discolouration.
VERSATILE – Seals glass to glass, glass to aluminium, glass to metal, and channel glazing. Use to seal worktops and laminated panels, timber and uPVC windows, and aluminium gutters.
FAST DRYING – Everbuild Everflex 225 Contract Industrial & Glazing Silicone skins over in ten minutes at 20˚C. Fully cures at a rate of 4mm per 24 hours, dependent on humidity and temperature.
EASY TO APPLY – Applies easily with a caulk, sealant or adhesive gun. We recommend the Everbuild Power Pro Heavy Duty Sealant / Adhesive Cartridge Applicator Gun.
MULTIPLE COLOURS: Also available in white, black, and brushed steel.

Everbuild White External Frame Sealant - 4 Tubes

6% Off

Why We Love It

Long-lasting, flexible, mould resistant.
Internal and external use.
Over paintable once cured.

Main Highlights

Suitable for internal and external use around window and door frames (Internal only on PVCu)
Provides a permanently flexible, long lasting, mould resistant seal
Also suitable to be used to seal cracks and gaps in brickwork, stone and concret
Once cured the sealant can be over painted if required with most paints
Sika Group was established in 1927 and produces and markets a wide range of state-of-the-art systems covering construction products, industrial manufacturing, automotive manufacturing and DIY products ranges

Sika Stixall – Extreme Power Sealant And Adhesive – Waterproof – Black – 290ml

Why We Love It

High grab strength, zero sagging.
Weather and water-resistant.
Bonds underwater or in rain.

Main Highlights

HIGH-PERFORMANCE – Crafted using hybrid polymer technology, it has incredible initial grab strength, zero sagging and fills gaps with ease.
IDEAL FOR INTERIOR AND EXTERIOR USE DEPENDING ON THE APPLICATION – Resistant to weather, water, temperature and chemicals, you can use this as an adhesive inside and out plus as an interior sealant. (NOTE: Crystal Clear colour is not suitable for exterior use)
VERSATILE – Has incredible high-grab adhesion to a wide range of materials, including glass, metals, plastic, concrete, wood, and so much more – it bonds even underwater or in the rain.
PROFESSIONAL FINISH – This quick-curing mix develops a skin in only 10 minutes and is paintable once completely dry with water-based paints for a high-quality finish to your DIY projects.
EASY TO APPLY – Insert the cartridge into your caulking gun, snip the tip and apply as needed to your chosen materials.
LONG-LASTING – This completely waterproof adhesive and sealant is resistant to temperature extremes between -40°C and +100°C, as well as a range of chemicals once fully cured, meaning it can be considered for durable applications.
MULTIPLE COLOURS – Available in Black, Brown, Anthracite, White, Crystal Clear and Grey

8.9

Excellent

We scanned 1837 products

We reviewed these offers relevant to the External Window Sealant within online retailers such as Amazon, eBay and other local retailers, ensuring we covered all major brands and models. The products we selected come from trusted brands like Everbuild, Unibond, Truly PVC Supplies, EVO-STIK, Sika, all of which have a reputation for consistently delivering high-quality products that users love and innovative approaches for function & design.

For the best External Window Sealant in the market, we considered we took a deep dive into 9186 online reviews , focusing on elements like user satisfaction, performance in real-world conditions, and long-term reliability. Our ranking also evaluates each review’s relevancy, authenticity, up-to-dateness and depth so that the comparison is more sound.

We concluded that:

The clear winner of our analysis is 12X Everbuild White External & Internal Acrylic Frame Sealant - 310ml. We love many things about this product by Everbuild. What sets it apart from the competition is Generous 310ml size. Convenient 12-tube box. Sleek white color.
The best value product for most shoppers and where user satisfaction is continuously the highest is Unibond Outdoor Extreme Repair - Translucent 294g by Unibond based on online reviews by bloggers, experts and online shoppers.
The biggest bargain at the moment for External Window Sealant and the best cost-to-value ratio is Everbuild – Everflex – 225 Contract Industrial & Glazing Silicone – Industrial and Glazing Sealant – Adheres to Most Common Building Materials – Transparent – 295mlat Everbuild with a 13% discount.
Our list of the best External Window Sealant is updated regularly to reflect new releases and changes in product availability, so be sure to check back often for the latest rankings and discounts.

10 Best External Window Sealant in The UK

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We scanned 1837 products

We concluded that: