Facade Cleaning Damage From High Pressure Cleaners?

In the case of facades with ETICS or in older designs, spontaneous cleaning with a high-pressure cleaner should be discouraged.

During the cleaning process, the water pressure or the force acting on the outer shell of a building cannot be optimally controlled due to the distance to the object that cannot be maintained. Smallest cracks in the facade or defects, such as. B. bulges are aggravated or broken up by the action of high water pressure. In the case of existing cracks or other damaged areas, it is difficult to determine in advance how far they will extend into an insulation layer. It cannot be predicted with certainty up to which level of the facade the cleaning water will act. It can happen that the high-pressure water penetrates deep into the building envelope. Between which layers it lands, whether between damaged areas of the masonry and the insulation or on the reinforcement remains open. This “uncertainty” poses dangers. The water that has penetrated will evaporate again after cleaning the facade and will also detach areas that have already been damaged, provided that they are only partially permeable to water vapor. Another risk is that insufficiently killed algae or other spores are moved into the background during high pressure cleaning. The consequences are explosive, they amount to total damage to the facade: if the moisture cannot escape completely, there is a risk of frost damage in colder months. In warmer periods, mold can form behind the plaster, and lichen may develop in secret. Due to gaps between the insulation boards, the cleaning water sometimes penetrates very deeply into the insulation composite. Especially houses of simple construction, when building materialsnot processed properly are affected.

Facade cleaning: undesirable effects

Another undesirable effect can be seen in the fact that the facade is more open-pored after a cleaning action has not been carried out properly and that color pigments may have been removed. Consequence: The outer walls get dirty faster, appearance and protection of the facade are impaired. Subsequent cleaning actions are much more difficult to carry out. Based on an attacked structure, algae and fungi can thrive better.

Not to forget:

Facades that are to be cleaned with the high-pressure cleaner and to be given a new coat of paint have to dry for up to six weeks under unfavorable conditions. If the drying time is insufficient, the paint will be damaged.