Like graffiti removal, facade cleaning is an important issue in the field of exterior wall maintenance on a house. Because fine dust, exhaust fumes, building dust, plant growth and moisture can cause discoloration on the facade and microorganisms can also multiply.
Algae, moss, mould and dirt, which forms the breeding ground for the organisms, can be removed relatively easily, depending on the type and structure of the facade. In this guide, we have compiled information on how and with which aids you can clean your facade (or have it cleaned).
When cleaning facades by hand or high-pressure water jet, you remove dirt, algae, mould, moss and more. Details on cleaning the facade: here in the guide!
Facade cleaning: Remove algae, dirt and mould
We have already summarised the reasons for algae and mould on the house facade in the article “Development and prophylaxis: Algae and mould stains on the house facade“.
In the following we would like to show you what you can do if no precaution has been taken and the outside wall of the house now looks unattractive.
Depending on the type of plaster, insulation cladding and other factors concerning the facade, the type and aggressiveness of cleaning must be designed.
Working by hand: Scrubbing brush and water
The first measures you should take when cleaning your facade are manual methods. Use lukewarm or warm water, a hard brush and for higher areas a scrubbing brush to remove dirt from the house wall by hand and individual pressure.
Especially with coarse, sandy plaster, the use of a high-pressure cleaner with a water jet can cause more damage than the cleaning makes up for.
The disadvantage of mechanical, manual cleaning with water is, of course, that no in-depth cleaning is possible with coarse-pored plaster structures.
Remove algae and mould with high pressure water jet
The manual work with brushes and similar tools should always be the first choice when cleaning the facades of the house.
Only in the case of heavy soiling, fine dust, stubborn building dirt or deep-seated mould is a high-pressure cleaner with a strong water jet the step to be taken.
Also soot from fires or other, special soiling can be removed quite comfortably. By the way, natural additives to water for the fight against microorganisms are vinegar essence or soda (one spoon per litre of water).
Household remedy against algae growth, moss and Co.
This porridge, which you can use to clean the facade, can still be used in private households and is also environmentally friendly:
- 500 g cornstarch
- 100 g soda ash
- 5 l water
- Or everything extrapolated accordingly to your requirements
Apply this mixture to the house wall or to the individual affected areas. After four hours of exposure, you can wash the mixture off again or blast it with a high-pressure water jet.
In the case of sensitive facades or sandy plaster, it is best to brush the paste off by hand using circular movements. Use warm water for this – preferably in the early afternoon so that the facade can dry well afterwards.
Cleaning of the facade with wood panelling
Cleaning a wooden facade is a special topic. Because if you decide to use a high-pressure water jet, you should adjust its strength or pressure precisely so that you do not damage the wood.
In most cases, however, even at low pressure, you will remove the surface protection of the wood anyway, which is why after cleaning the facade a new treatment and painting should be a priority.
However, before using heavy equipment, try cleaning the facade with a brush, scrubbing brush, etc.
Use of biocides, fungicides, pesticides? Better not!
The use of chemical substances which are used as biocides, fungicides or pesticides is not recommended in connection with facade cleaning.
Although these chemicals kill a wide variety of micro-organisms from algae to moss and mould, they enter the soil and thus the groundwater when washed up or during the next rainfall.
And even if this goes into the sewerage system, there is no guarantee that purification and treatment plants will filter out or neutralise the substances.
A long-term exposure as well as a health risk for humans, animals and the environment are therefore likely. Therefore the means of choice for facade cleaning should only be water, vinegar, sodium bicarbonate and co.
That is why there is more and more pollution on facades
There is a tendency for more frequent soiling and more frequent growth on the facades of houses. This is mainly due to the ever increasing energy efficiency of properties.
With appropriate insulation of the walls, i.e. thermal energy insulation, less thermal energy is transported from inside the house to the outside. Ergo, the outside surfaces are cooler and the moisture on them evaporates more slowly or not at all.
Ideal conditions for algae, especially when fine dust and dirt provide a breeding ground. In addition, at high humidity a cool house wall leads to condensation of water, which also has a positive effect on the development of microorganisms.
How to prevent effectively
If you are currently planning a facade or want to modernise the existing one, then you have the best conditions for structural prophylaxis.
You should opt for a rear-ventilated exterior facade, which prevents the accumulation of moisture or promotes the evaporation of moisture through good air circulation.
In addition, clinker bricks instead of plaster are more suitable when it comes to the permanent appearance of the exterior wall of the house. This is because plaster does not store much heat, but absorbs water.
Clinkers, on the other hand, can store the heat energy of the sun and are less susceptible to moisture and dampness. They can even survive short rain showers dry.
Water-repellent facade paint, horizontal barrier and wall paste
If there are currently no plans to rebuild or structurally modernise the wall, insulation and/or facade, then you should use the appropriate facade paint, a facade cream or, in the case of moisture from the ground, a horizontal barrier to combat the causes of algae, mould and other soiling.
We naturally recommend proPERLA® facade paints and creams for this purpose. The paints are particularly suitable for plaster; the cream is effective on masonry, clinker bricks and similar forms.
The horizontal barrier ensures that moisture from the ground and cellar is kept out of the higher masonry.
Information about our products
Please feel free to visit our homepage and the menu item “Systems” to find out more about the individual colours and sealants.
Once applied and dried, the individual products are water-resistant, breathable and self-cleaning. In addition to solutions for facades, we also offer products for roofs and floors. Please contact us if you have any questions.