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Sealants & Adhesives

Sealants and adhesives are essential for bonding, sealing, and protecting materials in construction and DIY projects. Whether you’re fixing, filling gaps, or creating waterproof seals, our range includes high-performance products suitable for a wide range of applications.

From grab adhesives for strong instant bonding to silicone sealants for flexible waterproof finishes, we supply reliable solutions for both trade professionals and home users.

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  • BOSTIK%20PRO%20SEALANTS%20-%20S21%20SILICONE%20310ML%2030623036%2C%2030623039%2C%2030623041%2C%2030623054%2C%2030623110.png

    Bostik Pro Sealant S21 Multi Purpose Silicone Clear 310ml

    This Bostik S21 310ml multi purpose Silicone Sealant is a clear coloured professional grade, acetoxy silicone sealant for sealing glazing, frame and sanitary joints. This low modulus silicone sealant is suitable for interior and exterior use and offers...
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    Bostik Pro Sealant S30 Acetoxy Sanitary Silicone Clear 310ml

    Professional grade acetoxy silicone sealant for sanitary joints. S30 is a professional grade acetoxy sanitary silicone sealant developed for sealing sanitary joints. Sanitary joints are continually exposed to moisture and humidity. This acetoxy silicone...
  • BOSTIK%20PRO%20SEALANTS%20-%20S21%20SILICONE%20310ML%2030623036%2C%2030623039%2C%2030623041%2C%2030623054%2C%2030623110.png

    Bostik Pro Sealant S21 Multi Purpose Silicone Black 310ml

    A professional grade black S21 multi purpose Silicone Sealant. Features acetoxy silicone sealant for sealing glazing, frame and sanitary joints. This low modulus silicone sealant is suitable for interior and exterior use and offers up to 20% movement...
  • BOSTIK%20PRO%20SEALANTS%20-%20S21%20SILICONE%20310ML%2030623036%2C%2030623039%2C%2030623041%2C%2030623054%2C%2030623110.png

    Bostik Pro Sealant S21 Multi-Purpose Silicone Grey 310ml (30623110)

    Bostik S21 Silicone is a professional-grade acetoxy silicone sealant designed specifically for both glazing and sanitary joints. Its low modulus property ensures flexibility while maintaining durability, making it suitable for various applications across...
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    Bostik Pro Sealant S21 Multi-Purpose Silicone White 310ml

    Bostik S21 multi purpose Silicone Sealant is a professional grade, acetoxy silicone sealant for sealing glazing, frame and sanitary joints. This low modulus silicone sealant is suitable for interior and exterior use and offers up to 20% movement...
  • BOSTIK%20PRO%20SEALANTS%20-%20S30%20SILICONE%20310ML%2030623035%2C%2030623038%2C%2030623293.png

    Bostik Pro Sealant S30 Acetoxy Sanitary Silicone Grey 310ml

    Professional grade acetoxy silicone sealant for sanitary joints. S30 is a professional grade acetoxy sanitary silicone sealant developed for sealing sanitary joints. Sanitary joints are continually exposed to moisture and humidity. This acetoxy silicone...
  • BOSTIK%20PRO%20SEALANTS%20-%20S30%20SILICONE%20310ML%2030623035%2C%2030623038%2C%2030623293.png

    Bostik Pro Sealant S30 Acetoxy Sanitary Silicone White 310ml

    Professional grade acetoxy silicone sealant for sanitary joints. S30 is a professional grade acetoxy sanitary silicone sealant developed for sealing sanitary joints. Sanitary joints are continually exposed to moisture and humidity. This acetoxy silicone...

Sealants & Adhesives

Grab adhesives

Ideal for strong, instant bonding without the need for nails or screws:

Perfect for flexible, waterproof sealing:

  • Bathroom sealants
  • Exterior silicone
  • Weatherproof sealants
  • Expanding foam

Used for filling gaps and insulation:

Specialist adhesives & sealants

Designed for specific materials and applications:

  • Wood adhesives
  • Masonry sealants
  • High-temperature sealants

Choosing the right sealant or adhesive

When selecting sealants and adhesives, consider:

  • Application – bonding, sealing, or gap filling
  • Environment – interior or exterior use
  • Water resistance – essential for bathrooms and outdoor areas
  • Material compatibility – wood, metal, masonry, or plastic

Complete your project

You may also need:

If you are working on a new project or renovating an existing outdoor space, pop into your local Howarth branch or browse our website. We also offer Click & Collect and Delivery options.

Shop Sealants & Adhesives by Type

Frequently Asked Questions

How to use silicone sealant?
To use silicone sealant, prepare the area that needs to be sealed, apply the sealant, smooth the sealant, and then leave it to dry.
How much tile adhesive do I need?
You will need 1.8kgs per 1mm depth per m2.
How to mix grout?
To mix grout, add water to the grouting powder in the manufacturer-recommend ratio. Tilt mixing bucket and stir with a grout-mixing knife. Then, adjust grout consistency by adding more powder or water. Let the grout rest for up to 10 minutes before using a grout knife to mix thoroughly once more.
How to use wood filler on a door frame?
To use wood filler on a door frame, start off by scraping out any flaking and splinters of paint from the damaged parts by using a wire brush. Then, it is important to soften or mix the filler as per instructions. It could involve stirring to the point of hardening, kneading until it softens, or mixing different substances until you get a similar colour. At this point, apply the ready filler on a putty knife. You will then scrape it onto the frame’s damaged area. After you’ve done that, allow a reasonable time for the filler to dry.
How to use expanding foam?
To use expanding foam, first clean the area, removing any debris and dirt to ensure there will be no contaminants. Put on disposable gloves to ensure you stay as safe as possible (as expanding foam can burn and will stick to your skin if it gets on you), prepare the can by removing the top and screwing in the applicator nozzle onto the valve, making sure not to use too much. Then, finally, shake the can well and then insert the nozzle into the hole you wish to fill, holding the can upside down for the best application. Make sure to leave the foam to set, which will take between 30 minutes and 12 hours depending on the amount of foam you’ve used. Once the foam has dried, you can cut and sand it down to the desired fit.
What is grab adhesive used for?
Grab adhesive is used for bonding materials quickly without the need for screws or nails.
What sealant is best for waterproofing?
Silicone sealants are commonly used for waterproofing due to their flexibility and resistance to moisture.
Can sealants be used outdoors?
Yes, exterior sealants are designed to withstand weather conditions and provide long-lasting protection.