An efficient way to get rid of algae and fungi from the facade

Algae and fungi, commonly referred to as mould, are often found enemies on our facades. However, the invaded facade can be cleaned and protected.

If the facade of our house has been attacked by algae and fungi, we need to do the following:

  • remove them mechanically;
  • destroy their traces, including invisible spores by taking advantage of chemicals;
  • fix the damaged plaster and paint, and if necessary also the flashings;
  • protect the restored surfaces against redevelopment of undesirable microorganisms;
  • finally, finish the restores facade, generally by painting it.
Simultaneous impact of algae on the wall (green colour) and fungi (brown and black residue). Algae and fungi can often be found together.

As we can see, actions are complex and cover also protection of walls for future. Since it makes no sense if the problem will recur in a few months. Fortunately, when we use appropriate and modern agents, certain works can be facilitated and accelerated. A good example are plasters and paints, which due to their chemical composition (strongly alkaline reaction of silicate products, low absorption and resistance to settling of impurities, silicate and acrylic paints with Teflon additive)prevent undesirable microorganisms from development.

The first stage, i.e. mechanical surface cleaning, is removing residues with putty knife or brush, or water under high pressure (pressure washer). All these works must be performed carefully, so as not to damage the existing plaster. It’s not recommended to use a dry brush, as this contributes to formation of dust containing fungal algae spores. Consequently, we can distribute them onto a large surface, moreover this dust is potentially hazardous for humans. Therefore, it’s best to remove residues with a wet brush. In addition, some agents for eliminating algae and fungi are intended for use at this very stage. We apply them in large quantity, leave them for a few days, so that are able to destroy the microorganisms on the facade and then we perform the first cleaning.

Wczesny etap porażenia przez glony.

Regardless of a method used, either mechanical or chemical agents, we need to wait until the walls dry. This initial cleaning does not guarantee removal of fungi and algae completely. Their residues are still visible, and if not, microscopic spores will certainly survive on the plaster. Therefore, the next stage is application of an agent eliminating fungi and algae. It can be, for example.: Foveo Tech RG 10RG 10 Fungicide and Algaecide AgentRG 10 Fungicide and Algaecide AgentSee more. We apply it in large quantity (even 250 ml/m2) with paintbrush, roller or sponge. In practice, it is impossible to do it well at one time, it’s better to repeat this operation 2-3 times, when the previous coating is almost dry. According to the time provided by the manufacturer - from several hours to several days - the rest dead residues of algae and fungi must be removed mechanically or with water under pressure. This cleaned area should be left till drying and next apply a biocidal agent. It will ensure protection for future.

Zielone plamy typowe dla alg.

After these procedures we can commence plaster repair works as well as faulty flashings contributing to damp patches. While cleaning it often turns out that the plaster under the coat of residue is weakened and damaged by fungi and algae (they penetrate the deeper layers), or it was damaged during works. The restored areas should be covered with a biocidal agent. While carrying out restoration in these areas we use the same plaster type as previously. The final stage is facade painting, it is recommended to use a product of enhanced resistance to fungi and algea (e.g. silicate, siliconeFN 30 Exterior Silicone PaintFN 30 Exterior Silicone PaintSee more, acrylic with Teflon), however, it must always be approved by the manufacturer for use on a specific type of plaster.

Then we need to take care of the facade on regular basis. At least once a year we should inspect it carefully and carry out necessary repairs (e.g. repair leaking gutters contributing in damp patches), if necessary, remove residues of algae and fungi, as soon as they occur. Since it’s better to prevent than treat.