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Impregnator Vs Sealer – What Is The Difference?

Impregnator Sealer

'Impregnator', 'sealer', even 'impregnating sealer' are all terms you will see a lot when researching exterior waterproofing treatments & coatings. But what is the difference between them? In this guide we are going to answer all of the most common questions regarding impregnators & sealers so you can find the right waterproof treatment for you.

The Background

In the UK, our homes must endure large amounts of rain & weathering almost all year round. For this reason, protecting exterior surfaces is something that many homeowners want to do in order to protect their home.

Contrary to popular belief, mineral building materials such as brick, concrete, stone, paving, roof tiles & wood are all porous, meaning they absorb moisture. The more porous a surface, the more liquid or gas can pass through voids & be held in the material.

Moisture is the single biggest cause of building material deterioration. This is because when the temperature drops, any moisture that is present in building materials, whether it is masonry or roof tiles. can undergo a freeze-thaw cycle. 

This is the process in which moisture freezes from a liquid into a solid, causing it to expand. The result of this is that the water within building material expands when it freezes. This movement causes cracks in the material to open up, allowing more moisture to enter and continuing a cycle of deterioration. With masonry surfaces particularly, the moisture within the material can also lead to the strength of the mortar within the brickwork to weaken.

Moisture can also create the ideal environment for moss, lichens & other green growth to develop on & in-between building materials. In the case of roof tiles, by growing in the gaps between roof tiles, moss can compromise the ability for your roof to keep out moisture. If moss is allowed to grow on your roof, the moisture that the moss soaks up can cause roof tiles to rot due to the consistent exposure to moisture. Furthermore, the growth of the moss will fill the gaps between the roof tiles, which can move & damage the roof tiles. This is because the moss soaks up water & expands, which can compromise the bond between the adjoining materials that ensure the integrity of the roof. Eventually, roof tiles can crack under the movement.

Lastly, exterior surfaces, especially in the wet conditions here in the UK, can be left discoloured from moisture stains. Furthermore, the moisture can provide the perfect conditions for moss, lichens & other green growth to thrive, causing a significant loss to the kerb appeal of paving, timber, masonry & roof tiles.

In summary, there are a whole host of problems that are associated with water ingress on building materials, which is why preventing this moisture is crucial if you want dry, clean & protected exterior surfaces.

Impregnator Vs Sealer

This is where waterproofing treatments come in, which are designed to prevent this water ingress and keep exterior surfaces dry.

Unfortunately, in the UK there is a lot of conflicting information regarding waterproofing treatments, with many people confusing sealers & impregnators. These both refer to clear waterproofing treatments that are used to prevent water absorption.


Sealers refer to water repellent treatments that prevent water absorption. They achieve this by creating a waterproof film on the surface of the material.

While preventing water absorption, these sealers do what the name would suggest, which is seal the surface. This sealing film that is created can impact the breathability of the material, preventing water vapour from freely passing through the surface. By preventing this breathability, any moisture that finds its way underneath the film from any hairline cracks becomes trapped. Eventually, the build-up of moisture will cause the film of the sealer to break under the pressure & leave the surface unprotected once again. Think of wrapping a surface in cling film. Yes, it will prevent water getting in, but it will trap anything inside from escaping.

In the case of masonry, apply a sealer can be particularly detrimental to the health of the property. By sealing the surface and not allowing water vapour to escape, moisture that naturally occurs from condensation within the property will become trapped. The moisture will build-up within the property and cause significant damp problems, not to mention the breakdown of bricks and mortar from the high levels of moisture. Instead of preventing damage to bricks and damp, which is what they are designed to do, they accentuate these problems even more.

While these products are often clear, invisible treatments, as they form a film on the substrate they can leave an unnatural sheen on the material which is undesirable for many.

When they exist in a coloured system in the form of a waterproof masonry paint for example, the build-up of moisture will eventually cause the paintwork to peel & flake off the substrate, leaving an untidy finish on the property.

A sealer should only be used if you are looking for a short-term waterproofing solution on a small area. Even in this scenario, they should be used with caution.


An impregnator is a waterproofing treatment just like a sealer, however it achieves this in a different way. In contrast to a sealer, an impregnator works below the surface of the building material, rather than creating a film.

It does this by chemically bonding and penetrating into the material. Instead of sealing the pores of the material, it lines the pores. This means that while water cannot enter the substrate, any water vapour can still freely travel through the pores and breathe out.

The best way to think about an impregnator vs a sealer is that an impregnator waterproofs the substrate itself, while a sealer creates a waterproof film on the substrate.

Long-term, with no film to break and with the breathability of the building material maintained, the lifespan of an impregnator far exceeds that of a sealer.


  • Water Repellent
  • Highly Breathable
  • Lifespan of over 10 years
  • Self-cleaning
  • Penetrates into substrates
  • Does not alter the appearance


  • Water Repellent
  • Not Breathable
  • Lifespan of over 1-3 years
  • Creates a film on the surface of substrates
  • Offers a clear treatment, although a sheen can be left on the surface
Clean roof

Containing the latest nano technology, ProPERLA impregnating treatments create a super hydrophobic surface that repels water, preventing up to 96% of water absorption. This is caused when water droplets are unable to stick to the treated surface, instead simply forming beads on the surface of the paving.

While preventing water absorption, the impregnators also remain highly breathable, allowing water vapour to naturally pass through the substrate.

By creating a super hydrophobic substrate that repels water, ProPERLA technology also has self-cleaning properties. This is because any dirt on the surface is simply cleaned off with any rainfall. The super hydrophobic technology also discourages the growth of moss, lichens & green growth, as well as preventing any staining or discolouration from moisture. This significantly reduces the maintenance of exterior surfaces, allowing them to stay looking clean & pristine for decades.

ProPERLA icons

ProPERLA super hydrophobic impregnating technology is available for a range of substrates, including roof tiles, brick, concrete, stone, paving & timber:

  • ProPERLA Water Repellent - an advanced clear roof waterproofing treatment for mineral building roof tiles such as clay, concrete, terracotta, natural stone and slate.
  • ProPERLA Masonry Creme - a masonry protection cream that keeps properties warm & dry by creating a super hydrophobic coating on a range of substrates, including brick, stone & concrete.
  • ProPERLA Wood Impregnator - a clear waterproof coating for wood that provides long lasting weather protection for timber, preventing rotting, green growth & discolouration.
  • ProPERLA Paving Impregnator - an advanced waterproof treatment for patios & driveways that provides protection against weathering & discolouration.

In the case of ProPERLA Masonry Creme, this is our most popular impregnator. This is because of the nature of masonry surfaces. Roughly 35% of all heat loss in a home occurs through the walls which is caused by exterior walls becoming saturated with water. Tests have shown that a damp content of 5% in a plain brick wall can lower the insulation performance by up to 50%. By keeping walls dry, ProPERLA Masonry Creme helps to improve the thermal efficiency of a property.

In independent testing, ProPERLA Masonry Creme was found to keep a masonry wall 6⁰C warmer on average in comparison to the uncoated walls. For this reason, ProPERLA Masonry Creme has been verified by the Energy Saving Trust following their independent review process.

Testing conducted also found that both ProPERLA Masorny Creme & ProPERLA Water Repellent have a proven 25 year performance in the harsh weather conditions, ensuring their performance without failing for decades to come. This is in contrast to less advanced sealers that last between 1-3 years.

How Do I Treat My Surfaces With ProPERLA Impregnators?

ProPERLA impregnators contain a specialist technology that must be applied by experts in order to ensure maximum performance.

We have a number of approved ProPERLA applicators up and down the UK who have attended our rigorous training program to ensure they apply the impregnators to the highest level. To find an approved ProPERLA applicator, simply type your postcode in our applicator finder tool and find your nearest applicator, who can carry out a full block paving restoration for you.

ProPERLA waterproofing technology

Frequently Asked Questions

Q. How do I become an approved applicator of ProPERLA products?

To ensure our products are only applied by trained experts, we ensure that applicators attend our training course in order to become an approved applicator of ProPERLA products. Why not read more about our training course if you would like to be able to offer ProPERLA technology to your clients?

Q. Does an impregnator alter the appearance of paving?

By penetrating into the substrate, an impregnator does not leave any finish or alter the appearance of the surface in any way. A sealer may potentially leave a sheen as it creates a film on the surface.

Q. How long do impregnators last?

In the case of ProPERLA impregnating products, these have not all been fully tested to their maximum lifespan. ProPERLA Water Repellent & ProPERLA Masonry Creme have both been tested in a 25 year accelerated weathering process that found at the end of 25 years of harsh weather conditions, there was no sign of deterioration in performance or appearance. 

All ProPERLA products come with a manufacturer guarantee of between 10-20 years, which completely ensures the performance of the product & protects you from any product failure. Having said this, the lifespan of the products far exceed this guarantee.

Q. Is this technology available in colours?

ProPERLA super hydrophobic technology is available in coloured form for walls & roofs. While these products remain highly breathable, they must apply a film in order to create a coloured finish, which is why they are not considered impregnators. Having said this, they are not sealers as they still line the pores of substrates without sealing them, meaning full breathability is maintained. 

Q. Should natural stone be waterproofed?

We would recommend that you protect any natural mineral surface to ensure they last a long time looking their best. With natural stone being a very porous substrate, it can be particularly prone to water ingress, meaning waterproofing it can be highly beneficial for protecting the surface.

Want to speak to one of our technical advisers for further advice on impregnator sealers? Send them an email to info@properla.co.uk & one of the team will be on hand to assist you with any questions you may have.

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