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Waterproof Sealant

Waterproof Sealant: Instant Seal Even in Wet. Stops Leaks

Adiseal waterproof sealant is a high-performance product that provides a watertight seal in dry, damp, or wet conditions. It provides a strong, flexible, water-resistant, weatherproof and durable seal, outperforming other sealants like silicone sealants.

Adiseal waterproof sealant is ideal for emergency repairs in wet conditions like rain to stop drips or leaks instantly and protect your property from moisture damage. It is available in clear plus other colours and is suitable for both indoor and outdoor waterproofing sealing applications.

Waterproof sealant underwater sealing a leak demonstration.
Waterproof sealant demonstration, sealing a leak instantly underwater.


Why choose Adiseal waterproof sealant?

Adiseal industrial strength waterproof sealant excels in instantly sealing leaks in dry or even in challenging wet conditions like rain. In our demonstration video below, we sealed a large 10mm by 250mm hole in a water-filled plastic tub instantly by applying Adiseal underwater, sealing the leak immediately even with water pouring through the hole.

Waterproof sealant demonstration video

What are the benefits of Adiseal waterproof sealant & adhesive?

  • Works in dry, wet, even underwater
  • High grab adhesive (for even more grab, use Adiseal Hi-Grab)
  • Gap filler sealant
  • Resists mould
  • Over paintable (paint can be mixed into Adiseal Ultra Clear to make custom coloured sealant)
  • Non-brittle (remains flexible)
  • Waterproof adhesive
  • Water-resistant sealant
  • UV resistant
  • Virtually odourless (no harsh smell when applying product)
  • Isocyanate free
  • Solvent free (safe for use on sensitive materials)
  • No shrinkage or cracking (provides a better and longer lasting seal)
  • Flexible sealant adhesive
  • Prevent fungal growth
  • Prevent bacteria growth
  • Good resistance to chemicals
  • EC1 Plus certified (No VOC)
  • ISEGA certified – safe for use in food preparation areas
  • Suitable for indoor & outdoor adhesive sealant use
  • Strong sealant


Best mould resistant sealant

In our tests evaluating mould resistance of various sealants, Adiseal emerged as the top performing sealant. We applied the various sealants in clean plastic cups, filled them with tap water, covered them and left them for several days. Despite prolonged exposure to the water, Adiseal sealant demonstrated the strongest resistance to mould growth compared to other products tested.

Strong mould resistant waterproof sealant test. Adiseal vs CT1
Strongest mould resistance test results.


What is the best clear waterproof sealant?

Adiseal Ultra Clear waterproof sealant lives up to its name, staying genuinely clear unlike some alternatives that become cloudy after application. Unlike cheaper silicone sealants that say clear but are cloudy instead, Adiseal Ultra Clear remains crystal clear, whether dry or wet, making it the superior choice.

We conducted a test to demonstrate Adiseal Ultra Clear’s ability to maintain its clear appearance even after extended submersion in water.

Adiseal Ultra Clear has strongest colour retention in water

Clear waterproof sealant in water comparison. Adiseal Ultra Clear vs CT1 sealant clear
Colour retention of sealant. Test in water.


Colour retention test of clear waterproof sealant

We tested the clear waterproof sealants ability to keep clear by applying them inside new plastic cups. We then filled the cups halfway with tap water, covered, and kept under identical conditions for several days.

Clear sealant test in water. Adiseal Ultra Clear sealant has stayed clearest.
Waterproof sealant clear test results in water.


Adiseal top in colour retention test

After several days of being submerged in the same water, Adiseal outperformed competitors, staying clear both above and below the waterline. In contrast, competitor waterproof clear sealants turned white below the waterline. As can be seen in the image above, 1 competitor sealant also turned white above the waterline.


How to apply a waterproof sealant

How to apply a waterproof sealant.

  1. Clean the surface

    To get a good long lasting seal, making sure the surface is clean is vital before applying the sealant. If there is any grease, dirt or mould, clean that first before applying the product.

  2. Cut the Nozzle:

    Cut the nozzle of the sealant tube making an opening that matches the desired bead size.

  3. Apply Sealant:

    Apply a steady, even bead of sealant along the intended joint or area. Maintain consistent pressure for a uniform application.

  4. Smooth the Bead:

    Use a caulking tool, spatula, or your finger (wearing a glove) to smooth and shape the bead, ensuring good coverage and a neat finish.

  5. Cure Time:

    Allow the sealant to cure as per the manufacturer’s instructions. This could take several hours to a day, depending on the product and environmental conditions.

  6. Clean Excess:

    While the sealant is still wet, wipe away any excess with a damp cloth or sponge. If the sealant has dried, carefully trim away excess using a utility knife.

  7. Test the Seal:

    Test the sealant’s effectiveness by applying water to the sealed area after it has cured. Unlike some sealants, such as Adiseal, which can be tested immediately after application, even before full curing.

Tip: To store Adiseal once opened, leave about 1cm worth of product out of the nozzle and store the tube upright in a cool dry place. Adiseal requires moisture for it to cure. The exposed part out of the nozzle will cure creating a cap. To re-use Adiseal, pull the cured part out or cut the nozzle until the uncured part is reached.

Internal and external weatherproof sealant

Adiseal is a versatile industrial strength sealant ideal for both indoor and outdoor use, excelling as a weatherproof sealing solution for various applications. Its high UV resistance, flexibility, and ability to withstand high temperatures make it perfect for outdoor sealing projects. Additionally, it cures underwater, prevents mould growth, and sustains adhesion when exposed to water, making it an exceptional choice for instant sealing in rainy conditions, particularly for roofs and gutters.

Permanent submersion

Adiseal can seal and bond underwater but isn’t designed for constant submersion. When using Adiseal to affix a tile in a pool filled with water, it’s crucial for the tile and grout to act as a barrier, preventing water from reaching the adhesive after installation. Adiseal can be suitable for such applications, even in pools permanently filled with water.

What types of surfaces do waterproof sealants work on?

They can be applied to a number of different material surfaces including wood, metal, concrete, stone, plastic, glass, ceramics, brick and many more.


Waterproof sealant for wood

We demonstrated Adiseal’s exceptional waterproofing ability on wood by applying it to wood and brick surfaces in dry, damp, and wet conditions. This showcased its strong adhesion and weather resistance, depicted in the accompanying images.


Applying strong sealant on wood & wet brick.
Applying waterproof sealant on wood and wet brick.
Grab demonstration on wood & brick.
Instant grab demonstration of sealant on wet surfaces.


Waterproof sealant for plastic

For a versatile waterproof sealant suitable for various materials, including plastic, particularly PVC, Adiseal provides a high-performance seal. It is however not recommended for use on certain plastics like polypropylene, polyethylene or polyurethane.


Waterproof sealant for metal

Adiseal is a versatile waterproof sealant for metal as well as other materials. Prior to application, it’s essential to clean the metal surface thoroughly by removing any oil, grease, or rust to ensure a long-lasting seal on metal.



Adiseal adhesive and sealant is available in the following colours:

Adiseal can also be manufactured in any RAL colour.

Can you paint over waterproof sealant?

It is also possible to paint over Adiseal once it has cured. It is recommended to test in a small area before painting.

Waterproof adhesive glue

As well as Adiseal being a great waterproof sealant, it is also an excellent waterproof adhesive glue. It will provide a flexible and waterproof bond on many different construction materials.

Where to buy?

In the UK, to buy waterproof sealant from Adiseal stockists, contact us for details of your local stockist. For other countries, they can be purchased from online sellers like www.guglue.com who can ship worldwide.



Frequently asked questions about waterproof sealant

What is the best external waterproof sealant?

Adiseal is the best external waterproof sealant. With its ability to seal instantly, even underwater, it’s the ultimate choice for all your sealing needs. Its high mould resistance makes it perfect for external use, and its clear formulation stays clearest even after prolonged submersion in water. Plus, Adiseal works just as well in the rain, making it the ideal weather resistant solution for your sealing needs.

What sealant can I apply in the rain?

Adiseal weatherproof sealant is built to perform in any weather, be it rain, dry spells, or even underwater. It seals instantly, perfect for patching leaks in gutters or outdoor structures, especially during rainy spells. Plus, it offers a durable, flexible seal that can brave extreme weather conditions.

Can any waterproof sealant be used as an electrical waterproof gel?

Standard sealant isn’t meant to be an electrical waterproof gel. Electrical insulation gel is made to handle high voltage and stay re-enterable for accessing connections. Using the wrong sealant can lead to electrical issues and hazards. Always opt for a product designed for electrical insulation.

How long does waterproof sealant last?

The lifespan of a waterproof sealant depends on factors like its quality, the environment, and how it’s applied. A high-quality sealant can last several years before needing a touch-up.

What waterproof sealant can be applied when wet?

Adiseal, a waterproof sealant, is effective even on damp surfaces, perfect for wet conditions. Its water-resistant properties guarantee reliable adhesion in various applications.

What is the best sealant to stop water?

Adiseal sealant can stop water leaks even in wet conditions. Adiseal can be applied in dry, damp, wet and even underwater to seal instantly. It provides a strong, flexible and durable seal.


Suhail Matadar has extensive experience in the construction industry as an electrician, involved in installing, inspecting, and testing electrical systems in various projects. He excelled in sales, working for a major UK wholesaler, selling construction products to professionals and the DIY market. Suhail's background includes working at a leading home emergency repair company dealing with trades people. With a BEng (Hons) degree in Electronic Engineering, Suhail has worked with PLCs in the nuclear fuel manufacturing industry. During his studies, he gained practical experience at a chemical manufacturing company known for producing award-winning cleaning, hygiene, and livestock protection products for over a century. Currently, Suhail runs a global business specialising in supplying, researching, testing, and distributing chemical construction products like adhesives and sealants.