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Waterproof Sealant

(Last Updated On: 3 June 2023)

Ultimate Waterproof Sealant | Seals Instantly

A waterproof sealant is designed to create a barrier to prevent water from pouring into or soaking into materials. A good quality waterproof sealant can help stop water causing damage to building materials and other items. Once applied to the material, the sealant needs to stay adhered to the material for it maintain its sealing properties.

For a high performance waterproof sealant, Adiseal is the choice for professional trades people. Outperforming other waterproof sealants on the market, Adiseal works seamlessly in dry, damp, wet, and even underwater conditions, making it the go-to choice for indoor and outdoor applications. It delivers instant leak-proof results and can seal leaks instantly even in the most challenging situations with water pouring out of a hole.

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

Instant leak sealing

To show how good Adiseal is at sealing a leak instantly, we conducted a demonstration to showcase its outstanding capabilities. We started by cutting a large 10mm by 250mm hole in a large plastic tub and filled it with water. Despite large amounts of water pouring out through the hole, Adiseal was applied underwater, and the leak was sealed instantly. The hole was a long and large one, with a significant amount of water gushing through it. The performance of Adiseal was nothing short of impressive, showcasing its ability to seal leaks even in the most challenging situations. With Adiseal, you can trust that your sealing needs will be met with ease.

Video of waterproof sealant sealing underwater.

Our product is available as a clear waterproof sealant and in other colours. Adiseal is the ultimate solution for internal and external applications due to it’s weatherproof sealant properties. It’s an ideal waterproof sealant for wood, plastic, metal, and many other materials.

Internal and external weatherproof sealant

Adiseal is suitable for both indoor and outdoor applications. It can function as an external weatherproof sealant as well as internal applications. It has high UV resistant properties, remains flexible and has excellent temperature resistance, making it the perfect choice for outdoor use. Whether you need to seal joints, repair leaks or protect against harsh weather conditions, the weather resistance properties of Adiseal will provide a reliable and durable solution.

A good weatherproof sealant also needs to be able to cure even underwater, resist mould growth as well as stay stuck to the material surface when in contact with water. Adiseal does all of these plus much more. This makes it a great outdoor sealant for use on a roof or gutter. With Adiseal, you can seal gutter even in the rain.

Best mould resistant sealant test

At Adiseal Ltd, we’re committed to providing our customers with the best waterproof sealant possible. That’s why we conducted several tests, including a mould resistance test, to determine the most effective product on the market. The test involved applying different products to new plastic cups filled halfway with tap water. The cups were then covered and kept under the same conditions to ensure fairness. After rigorous testing, Adiseal emerged as the clear winner, with the strongest mould resistance of all the products tested. In fact, in a head-to-head comparison with a competitor product claiming to be the number one product, Adiseal proved to be superior. Check out the image below to see the test results for yourself.

Mould resistant waterproof sealant test vs popular competitor. Adiseal has stayed mould free longest whereas *** sealant and adhesive has become mouldy.
Strongest mould resistance test results.


Mould resistance test result

As shown in the image above, Adiseal is the ultimate choice for preventing mould growth, even after prolonged exposure to water. In fact, after 90 days of being submerged in the same water, both the water and Adiseal remained mould-free, while the competitor product did not. The exceptional mould resistance properties of Adiseal ensure your surfaces remain clean and hygienic, providing long-lasting protection against harmful mould growth.


Clear waterproof sealant

Unlike other sealants that claim to be clear but appear cloudy or tinted when applied, Adiseal ultra clear waterproof sealant & adhesive lives up to its name. Cheaper silicone sealants are often cloudy or white in colour, compromising the overall aesthetics of the surface. With Adiseal ultra clear waterproof sealant & adhesive, you can be sure that your surfaces will maintain their clarity, while still being protected by a waterproof sealant that delivers reliable results.


Adiseal Ultra Clear has strongest colour retention in water

Clear waterproof sealant in water comparison. Adiseal Ultra Clear waterproof sealant has stayed clear whereas *** clear sealant and adhesive has turned white.
Colour retention of sealant. Test in water.

Adiseal also has the strongest colour retention when underwater. In fact, in a head-to-head comparison with a competitor’s clear product, Adiseal emerged as the clear winner. As the image illustrates, the competitor’s product turned white when submerged, while Adiseal maintained its clear appearance. This exceptional colour retention sets Adiseal apart from the competition, ensuring your surfaces maintain their aesthetic appeal, even in harsh underwater environments.


Colour retention test of clear waterproof sealant

To carry out the colour retention test of clear waterproof sealants in water, the products from the different manufacturers were first applied inside new clean plastic cups. They were then filled half way with tap water & covered. They were then kept in the same condition for a few days.

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


Adiseal top in colour retention test

In our tests, Adiseal emerged as the clear winner, maintaining its clear appearance both above the water line and underwater. In contrast, competitor waterproof clear sealants turned white below the waterline, failing to deliver the expected performance. Even a competitor product claiming to be the No.1 product performed poorly, turning white both above and below the waterline. Interestingly, the competitor’s old formula clear product actually performed better than their new version in this colour retention test.

Benefits of Adiseal Waterproof Adhesive & Sealant

The typical curing time for Adiseal adhesive is 24 to 48 hours. However, in colder temperatures, the curing time may increase. Adiseal requires moisture for it to cure which it usually gets from moisture in the air when used on a porous materials. If the product is applied between 2 non porous materials, then it is advisable to spray the surface with a little bit of water and give it extra time for it to cure.

How to use waterproof sealant

Details of how to use a waterproof sealant.

  1. Choose the right sealant for the job

    Make sure the sealant you choose is suitable for the surface you’re working on and the conditions it will be exposed to. Adiseal is a versatile sealant that works in dry, damp, wet and even underwater conditions.

  2. 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. Adisolve is ideal at removing dirt, grease, old sealant and other stubborn deposits.

  3. Apply the sealant

    With Adiseal, simply apply it to the area that requires sealing. Make sure any gaps are filled and covered. When applying the adhesive, instead of starting at the far end and coming closer, if you start closest to you and push forward, this will push the sealant into the gap. This will fill the gap more thoroughly and provide a better seal.

  4. Seals instantly

    Although Adiseal can usually take 24 to 48 hours to fully cure, it should be able to seal straight away. Other products require curing before they are able to seal. As Adiseal seals instantly, it can be tested immediately to see if it has created a proper seal.

  5. Remove excess

    Remove any excess sealant to achieve a clean finish. You can do this while the sealant is still wet, or if it has already cured, use a sharp knife to trim off any excess.


When using some waterproof sealants, it is important to consider the following safety implications:

  1. Proper Ventilation: Many waterproof sealants, especially if they contain solvents, emit fumes during application and curing. Ensure that the working area is well-ventilated to prevent the accumulation of fumes, which can be harmful if inhaled in large quantities. Open windows or use exhaust fans to promote air circulation.
  2. Skin Protection: Waterproof sealants are often formulated with chemicals that can irritate or cause allergic reactions on the skin. Wear appropriate protective clothing, such as gloves and long sleeves, to minimize direct contact with the sealant. In case of contact, promptly wash the affected area with soap and water.
  3. Eye Protection: Splashes or accidental contact of waterproof sealant with the eyes can cause irritation or injury. Wear safety goggles or a face shield to protect your eyes during the application process. If sealant gets into the eyes, flush them with clean water for several minutes and seek medical attention if irritation persists.
  4. Inhalation Precautions: Some waterproof sealants may release volatile organic compounds (VOCs) or other hazardous substances. Avoid breathing in the fumes directly by working in a well-ventilated area or wearing a respirator if necessary. Follow the manufacturer’s instructions regarding respiratory protection.
  5. Fire Safety: Certain waterproof sealants can be flammable or release flammable vapors. Keep away from open flames, sparks, or sources of ignition during application and curing. Store sealant containers in a cool, dry place away from heat sources.
  6. Read and Follow Instructions: Always read and follow the manufacturer’s instructions and safety guidelines provided with the waterproof sealant product. They will contain specific safety information, usage recommendations, and precautions for that particular product.

By taking these safety measures, you can minimize the risks associated with using a waterproof sealant and ensure a safer working environment.


While waterproof sealants offer effective protection against water intrusion, they do have certain limitations. Here are some common limitations of waterproof sealants:

  1. Surface Preparation: Proper surface preparation is crucial for the effectiveness of waterproof sealants. If the surface is not cleaned, dried, or primed adequately, the adhesion of the sealant may be compromised, leading to reduced performance.
  2. Application Temperature Range: Waterproof sealants have specific temperature ranges for application. If the ambient temperature is too low or too high, it can affect the curing process and the overall performance of the sealant. Extreme temperatures can cause cracking, reduced flexibility, or inadequate bonding.
  3. Joint Movement: Sealants are designed to accommodate a certain degree of joint movement caused by factors like building settling, temperature changes, or structural vibrations. However, excessive joint movement can strain the sealant and lead to failure. It is important to select an appropriate sealant that matches the expected joint movement.
  4. Limited Use on Certain Materials: Waterproof sealants may not be suitable for all types of materials. Some sealants are not compatible with certain plastics, rubber, or certain metals. It is essential to check the manufacturer’s guidelines and compatibility charts to ensure the sealant is suitable for the specific material you are working with.
  5. Lifespan and Maintenance: While waterproof sealants provide long-lasting protection, they are not permanent solutions. Over time, exposure to UV radiation, weathering, and environmental factors can degrade the sealant’s performance. Regular inspection and maintenance are necessary to identify any deterioration and reapply or repair the sealant as needed.
  6. Chemical Compatibility: Waterproof sealants may not be resistant to certain chemicals or solvents. If the sealed area comes into contact with substances that can degrade or react with the sealant, it may compromise its effectiveness and durability.
  7. Cure Time: Waterproof sealants require sufficient time to cure and achieve their full strength and water-resistant properties. During the curing process, the sealant may be vulnerable to damage or water exposure, which can affect its performance. It is important to allow the recommended curing time before subjecting the sealed area to moisture.

Understanding these limitations helps in selecting the appropriate sealant for specific applications and managing expectations regarding their performance. It is advisable to consult the manufacturer’s instructions and guidelines to ensure proper usage and maximize the effectiveness of the waterproof sealant.

Waterproof sealant for wood

To showcase the superior performance of Adiseal as a waterproof sealant on wood, we conducted a demonstration. In the demonstration, we applied the waterproof sealant on wood and brick surfaces in both dry and wet conditions. The images below demonstrate how Adiseal adheres to dry and wet surfaces, providing exceptional waterproofing and weather resistance.

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

Waterproof sealant for plastic

Adiseal is a versatile waterproof sealant for plastic that also works on a wide range of materials. It is highly effective in sealing most plastic materials, including PVC. However, it is not recommended for use on plastics such as polypropylene and polyethylene.

Waterproof sealant for metal

Adiseal is a versatile sealant that works effectively on various surfaces, including metal. However, it is crucial to clean the metal surface beforehand to achieve a long-lasting seal. Any traces of oil, grease, or rust must be removed before applying Adiseal to ensure the best possible results.

What can you use waterproof sealant on?

Adiseal is a versatile product that can outperform dedicated products. It has a wide range of adhesive and sealant applications, including as a waterproof sealant for roof, tiles, plastic, metal, doors, felt, and many other items. It can even seal leaking gutters, even in rainy conditions.

Where to buy?

In the UK, Adiseal products can be purchased from Adiseal stockists. For other countries, they can be purchased from online sellers like www.guglue.com who can ship worldwide.

We are looking for exclusive distributors for other countries. Please contact us for more details.

Paint on waterproof sealant

It is possible to use paint on waterproof sealant if the product used is Adiseal. However, if the paint is oil or solvent-based, it’s recommended to test it in a small area first. To do so, apply the sealant on a disposable item, let it cure, and then apply the paint. Wait to see if the paint peels off or not. Most paints are suitable to use over Adiseal, but it’s always best to test it first.

Adiseal is available in the following colours:

Adiseal can be manufactured in any RAL colour.

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.

Can you paint over waterproof sealant?

It is possible to paint over waterproof sealant if the sealant is Adiseal. Most paints are suitable to use. If the paint is oil or solvent based, it is recommended to test first.

What sealant works in the rain?

Adiseal weatherproof sealant is designed to work in all weather conditions, including rain, dry, and even underwater. It seals instantly, making it ideal for fixing leaks in gutters or other outdoor structures during wet weather. The sealant also provides a long-lasting, flexible seal that can withstand extreme weather conditions.

What sealants are waterproof?

Adiseal is a waterproof sealant that works in dry, damp, wet, and even underwater conditions. Unlike most sealants, it does not require a dry surface to work effectively. This makes Adiseal the ideal solution for a variety of projects that involve exposure to moisture or water.

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

No, standard sealant is not suitable for use as an electrical waterproof gel. Electrical insulation gel is specifically designed to withstand high voltage and remain re-enterable, in case the electrical connections need to be accessed. Using the wrong type of sealant can cause electrical malfunctions and potential hazards. It is important to use a product specifically designed for electrical insulation purposes.


In conclusion, Adiseal is the ultimate waterproof sealant that delivers exceptional performance and reliability. It can seal leaks instantly, even in challenging situations with water pouring out of a hole. Adiseal is suitable for both internal and external applications, with high UV resistance and excellent weatherproof properties. It has been tested and proven to have the strongest mould resistance, ensuring long-lasting protection against harmful mould growth. Additionally, Adiseal is available as a clear waterproof sealant, maintaining the aesthetic appeal of surfaces. Whether you need to seal wood, plastic, metal, or other materials, Adiseal is the go-to choice for a strong 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.