Professional Construction Products

Developing high performance construction products through extensive research and testing.

Roof Leak

Roof Leak Sealant (2024) | Instant Fix, Seal & Repair Even in Rain

A roof leak can happen for many different reasons. Adiseal roof leak sealant is a great product to carry out emergency roof repair and also creating a permanent fix for a leaking roof. It works on both flat and pitched roofs.

Although Adiseal roof leak sealer will do a great job at fixing the leaking roof, it is best to get a professional roofer to diagnose & repair the roof.

Types of roof

There are 2 main types of roofs, flat roofs & pitched roofs. Flat roofs usually have felt stuck on whilst pitched roofs have either tiles or slates but sometimes even felt shingles. Flat roofs can also have other material on top to stop the water coming through.

Roof leak causing water to come through ceiling.
Roof leak causing water to come through ceiling.

Why a flat roof leaks

If a felt flat roof is leaking, the most probable reason is the felt has either developed a crack or the felt has peeled away from the surface it was stuck on. Rainwater will work it’s way into these gaps and will come through the ceiling. Sometimes the lead flashing can also come away from the felt causing a leaking roof.

If the flat roof has a different material other than felt then most probably it has developed a crack in the material. This can happen for a number of reasons including exposure to UV, expansion & contraction due to temperature changes, high wind & something walking on top of it.

Reasons for a pitched roof leaking

A pitched roof usually has tiles, slates or sometimes even roof felt shingles. Over time these tiles, slates or roof felt shingles can move out of place with strong winds or sometimes even break allowing rainwater to seep through the gap. Around a chimney there is usually lead flashing & pointing with sand & cement. This also can break away over time causing rainwater to come through the roof.

If the roof has roof felt shingles, usually the adhesive can break apart over time. This maybe because of UV radiation from the sun, expansion & contraction due to temperature changes or high winds. Sticking the roof felt shingles back on will usually fix the leak.

Flat roof leak repair with Adiseal

Adiseal roof leak sealer is a great product to repair a flat roof if it’s leaking. Adiseal will emergency repair the leaking flat roof instantly as well as a provide a strong long lasting seal.

Best sealant to repair roof leak. Seals roof leak instantly. Can be applied to wet surfaces and even in the rain.

Sealant for roof felt

The reason why Adiseal sealant & adhesive is a great product when used as a roof felt sealant is because Adiseal:

Works in dry, wet & even underwater

As Adiseal works in dry, wet & even underwater, it is possible to carry out an emergency repair on a leaking flat roof even if it’s raining outside.

Seals instantly

As Adiseal seals instantly, it is possible to check whether the flat roof leak repair has been carried out successfully. Once the repair has been carried out, pour some water on the roof to see instantly if it’s fixed.

Demonstration of waterproof sealant capabilities including seal a leaking roof instantly.

Provides a permanent seal

When using Adiseal to carry out a flat roof leak repair, Adiseal will also provide a permanent fix as well as an emergency repair. If done correctly, the seal will last for years.

Permanently flexible

Adiseal stays permanently flexible meaning it will not become brittle. With temperature changes, items expand & contract. With this expansion & contraction, products that are not flexible become brittle and will crack or break causing water to leak through it. This is not a problem with Adiseal sealant & adhesive as is stays flexible.

UV resistant

If the product is not UV resistant, there is a high chance it will fail very quickly. A roof is one of the main areas of a property where it will receive high UV radiation from the sun.

Cold applied

The traditional way to repair a leak on a flat felt roof is to use a blowtorch. This is a fire risk & not everyone will be comfortable with using a blowtorch. Adiseal can be cold applied directly from the cartridge without the need to use a blowtorch.

Solvent free

As Adiseal roof felt sealant & adhesive is solvent free, it does not shrink once applied. This is a common problem with other products. For these other products to cure, the solvent have to evaporate away, causing the product to shrink and come away from the surface it has been applied to. Cheaper products tend to have more solvents leaving a weaker bond than Adiseal.

Another problem with solvent based adhesive & sealants is that the solvents will attack sensitive materials like polystyrene which is a common insulation material in building roofs, walls & other places.

Strongest Adhesive

As well as Adiseal being a great sealant, it also proved to be the strongest adhesive in an independent adhesive strength test by Ultimate Handyman. In the test Adiseal was over 3 times stronger than the nearest competitor. Further details of the test are on the Adiseal page.

How to repair a flat roof leak

How to repair a flat roof leak

  1. Find leak location

    To fix a felt flat roof leak, first find out where the water is working it’s way through the felt. This will usually be a crack in the felt, or where the felt has peeled away from the roof. Pour some water on the felt roof to see how the water runs into the gaps.
    repair a felt roof

  2. Clean area

    Once the location of the leak has been found, to get the best results, thoroughly clean that area. Brush away any loose debris. Use Adisolve solvent cleaner to remove any oil, grease, bitumen & other stubborn deposits. A paint brush is good to use to brush away any small debris.

  3. Apply roof leak sealant

    Once the area has been cleaned thoroughly, apply the Adiseal sealant & adhesive into the crack or gap.
    Tip: If using Adiseal to seal a crack in the felt, start by applying Adiseal at the point where the crack is nearest to you and move away to the other end on the crack. This will push Adiseal into the crack creating a much better seal.

  4. Smoother over crack

    Once Adiseal has been pushed into the crack, apply extra Adiseal on top & use a smooth flat surface to flatten the sealant. To remove any excess Adiseal, use a thick cloth. Adisolve solvent cleaner can also be used to help remove any excess Adiseal.

  5. Test seal

    As Adiseal seals straight away, it is possible to test if the felt flat roof leak has been repaired immediately by pouring water around that area. Adiseal sealant & adhesive will take 24 to 48 hours to fully cure.

Adiseal is a multi-purpose product & will also fix a leaking gutter.

Adhesive for felt roof

As well as Adiseal being a great sealant for roof felt, it is also a great adhesive for roofing felt.

Adhesive for flat roof felt is required where the felt adhesive has failed.
Felt for roof requires adhesive.

Adiseal adhesive & sealant is ideal when used as an adhesive for roof felt shingles, felt lap as well as sticking larger felt sheets. The advantage of Adiseal over other adhesives is it will also provide a strong waterproof seal as well as sticking the roofing felt.

How to stick roof felt shingles & felt lap

To stick roof felt shingles make sure the surface where the adhesive will be applied is thoroughly cleaned. Use a brush to remove any loose debris. Adisolve solvent cleaner is the ideal product to clean & remove oil, grease, tar, bitumen & many other stubborn deposits.

Adiseal can be cold applied. Simply apply Adiseal adhesive & sealant to one surface & press down the roof felt shingle. Adiseal can take 24 to 48 hours to fully cure but seals instantly.

Pitched roof leak repair with Adiseal

If the roof leak is caused by tiles or slates moving away then the best way to fix roof leak is to replace the tiles or slates in the correct position. If the tiles or slates are broken then it is possible to carry out an emergency fix to the roof leak with Adiseal adhesive & sealant but please note once Adiseal has cured, it will have to be cut off. This may make the replacement of the tiles or slates more difficult so it should be avoided if planning to use Adiseal for an emergency repair instead of a permanent repair. With any roof leak, getting a professional roofer to repair the leaking roof is the best solution.

Adiseal adhesive & sealant can also provide a long lasting repair if the leak is caused due to the sand cement pointing breaking away usually on the chimney or between the chimney and the roof. To use Adiseal for this, thoroughly clean the area where Adiseal needs to be applied. Make sure all the loose debris is brushed away. Lightly tap the area to make sure there are no loose bits left. A paint brush is good at brushing away any loose debris.

Once thoroughly clean, apply Adiseal adhesive & sealant. Try to push it into the gap to get a good seal. Although Adiseal can take 48 hours to cure, it is possible to check whether the leak has been fixed straight away. Pour some water over the area to see if the leak has been fixed. Adiseal can provide a long lasting repair but it is recommended to get a professional roofer to fix the roof with roofing materials.

Clear roof sealant

Adiseal Ultra Clear can be used as a clear roof sealant. Just like the rest of the Adiseal adhesive & sealant range, Adiseal Ultra Clear also seals leaks instantly even in the rain. It will seal many different roofing materials.

Where to buy?

In the UK, to buy roof leak repair sealant please contact us for details of your local stockist. For other countries Adiseal products can be purchased from www.guglue.com

Frequently asked questions about roof leak sealer

How to fix roof leak?

To fix a leaking roof it is best to get a professional roofer to carry out the repair. There are many reasons for a roof to start leaking. Adiseal roof leak sealer can provide an emergency fix as well as a permanent repair.

How quickly will Adiseal stop a leak on a felt roof?

Adiseal will repair the leak instantly on a leaking felt roof. It can take Adiseal 24 to 48 hours to fully cure but the seal on the leaf is immediate. This makes Adiseal ideal for emergency repairs as well as permanent fixes.

Can Adiseal stick a felt sheet that has peeled off from the roof?

Yes, Adiseal will stick a felt sheet that has peeled off. It will provide a very strong long lasting bond and will also seal at the same time.

Will Adiseal stick roofing felt to lead?

Yes, Adiseal will stick roofing felt to lead. Make sure the surfaces are thoroughly clean to get the best result.

Will Adiseal do a emergency roof repair?

Adiseal will provide an emergency roof repair as well as a long lasting fix on a leaking roof. Once Adiseal has cured, it requires cutting off to remove it. On a pitched roof where tiles or slates require replacing, it is better to do this instead of an emergency repair.

How to stop a roof leak in the rain?

To stop a roof leak in the rain, first locate the gap where the rain water in working it’s way through the roof. Clean that area from any dirt and debris. Apply Adiseal into the gap, pushing it in to make sure the gap is thoroughly filled. This should stop the leak immediately even though Adiseal can take 24 to 48 hours to fully dry.

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.