Hydrotec since 1988
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Improved insulation due to a clean and well-moisture-protected wall

Facade protection | Protect an exterior wall from rain

Shortly after their construction, brick, stone and mineral plaster facades degrade due to the harmful effects of rain, frost, pollution and vegetation (mosses, lichens). It is therefore essential to waterproof facades to protect them.

Hydrotec offers the cleaning and waterproofing of your façades. Our damp proofing treatment is microporous the wall is made impermeable to rain but not to air. Thus, water in the form of vapour can always escape from the wall.

The treated wall becomes self-cleaning: vegetation and pollution do not encrust so easily. This treatment does not change the appearance of the treated wall. This avoids the damage caused by frost to the bricks, the loosening of the joints, the appearance of cracks.

Long-lasting preservation effect: by protecting the façade, water repellence prevents premature aging. The waterproofing of the façade walls also prevents the appearance of efflorescence (white lime stains caused by carbonation of the cement).

Increasedinsulating capacity of the material protected by a water-repellent quality: a wall impregnated with rainwater acts as a thermal bridge that brings the cold from the outside into the interior of the house.
If its walls remain dry, a building will already be a little more energy efficient.

Where ?

On natural facades (unpainted brick, natural stone, exposed concrete, etc.) exposed to wind, rain, atmospheric and road pollution (along a busy road, for example).


  • Salts appear as white concretions on the surface of the walls. They are white veils of free lime released during the carbonation of cement
  • Fragmentation, expansion, cracking of bricks. In the case of frost, the expansion of the water causes ruptures on the surface of the materials (bricks, blocks, joints, etc.).
  • Incrustation of mosses, lichens, algae, etc.
  • Incrustation of pollutants.

Why do it ?

  • Aesthetics: your facades recover a clean appearance. Self-cleaning: a treated facade no longer retains mosses or pollution. It cleans itself when it rains.
  • Conservation: the water repellence delays the aging of the substrate.
  • Increased insulation of the wall: a room whose walls are very dry is easier to heat.
  • Hydrotec offers a 10-year warranty on the damp proofing of facades.

Processing steps of injection treatment


Protection of vegetation and terraces

at the foot of the wall


Scaffolding installation

If necessary


Or use of Cherry picker

If necessary


Application of a cleaning product

and pressurized water cleaning


Patching holes, repairing joints

if necessary


Application of the selected water repellent

FAQ – find out more


As part of a home renovation program, cleaning and waterproofing the facades is part of the necessary waterproofing work.
Facade renovation includes cleaning, repairing defective joints by various processes, including the application of various cleaning products and water repellants for porous facades exposed to rainwater.
The waterproofing treatment is applied to porous substrates subject to capillarity and therefore to the penetration of rainwater (bricks, stone, concrete, mineral plasters).
The facade treatment with a water repellent product does not concern synthetic plasters which are water repellent by nature. There is also no question of injection treatment here.
There is also no question of injection treatment here.


Porous facades exposed to bad weather, rainwater runoff, pollution and microorganisms suffer and tarnish. In just a few years they can lose their original appearance.
Soot and various biological organisms such as lichens and green algae (often called “moss”, hence the name “anti-foam product” for the cleaning product that concerns them) become encrusted in facades, degrading and removing their aesthetic appearance.
It is possible to stop these damages by applying a water repellent preventively, if the facade is still in good condition.
If the facade is already dirty, the operation will be more difficult: cleaning can restore your home to some of its original shine.

Facade cleaning

It should be noted that the application of a water repellent product on a recent wall durably prevents its soiling. If the facade has not been the subject of a preventive treatment, then a scaffolding must be placed and its cleaning provided before applying the water repellent.

Choice of cleaning product
  • A facade contaminated by microorganisms (algae and lichens) will be the subject of a curative treatment by spraying with a biocide, generally a long-lasting fungicidal algaecide product. A bleach-based product kills microorganisms, but this treatment will not last very long.
  • A facade blackened by soot will be treated with a product based on surfactants and / or acid.
How to clean a dirty facade?

High pressure cleaning is carried out after spraying the cleaning agent.
If the facade is not too dirty, most of the time you can get pretty much back to the original condition, but there is no guarantee of the result on paper.
In this regard, we regret that “preventive” water repellency is not more strongly recommended by builders and architects.

Repair of joints

Damaged gaskets are replaced after cleaning. We repair a few joints, but when the facade has to be repointed completely, we advise customers to contact a specialized company

Waterproofing - how to waterproof a facade?

The waterproofing prevents the infiltration of rainwater and the penetration of polluting substances into the material. It thus prevents discoloration, deterioration and too rapid aging of facades.

  • Long-lasting waterproofing
  • Self-cleaning effect
  • Appearance and natural color of the facade will be maintained for many years
  • Blocking of organic developments (green moss, lichens, etc.)
  • Block the migration and efflorescence of salts present in the material.
  • Reduction of frost damage (loosening of joints, cracks, etc.)
  • Maintenance of the microporosity of the support
  • Maintenance of the initial appearance: after the product has dried, the treatment is almost invisible.

For the treatment of facades by water-repellent impregnation, Hydrotec uses a series of colorless products suitable for various substrates. Some products in the range are also valid as water repellent for roofs.
The application of water repellents is done by trickling (not by spraying), with a lance that has been removed from the nozzle.
The water repellent in cream form (CR505) is applied by brush.

Choice of water repellent

The most widely used water repellent by Hydrotec is called H205. This product has an excellent efficiency report from the BBRI, which awarded it Class A, that is to say, it shows the best efficiency among the products on the market.
Other products are used depending on the support and longevity expected for its effectiveness.

All the water repellents used by Hydrotec are made from SILANES-SILOXANES resins.
Silane molecules have a smaller dimension than siloxanes. Their combination makes it possible to obtain a very versatile water-repellent product, suitable for all pores of common materials.
Our water repellents are suitable for all supports encountered: natural stone, brick, concrete, mineral plasters. Their main differences are:

  • Diluent: aqueous phase or solvent phase.
  • Difference in concentration for very porous or slightly porous substrates.
  • CSTC approval (class A) for H205.
  • Creamy formula (CR505) for delicate brush applications without dripping.
  • A particularly effective water repellent for concrete floors (H305).
Is a water repellent breathable?

It is often said that a water repellent or paint should be “breathable”. This term is overused because water repellent does not breathe, but it must be microporous to allow water vapor transfer.