Problem - Algae
Green spots or areas on the paint film surface.

Possible causes

  • Humid, warm autumn and winter.
  • The paint contains too few anti-algae agents.
  • Algae normally occurs on damp surfaces with little or no direct sunlight.
  • Structural features that allow humid conditions, for example, absence of plinth, unprotected fences, or insufficient ventilation.
  • Vegetation nearby.


If repainting is not required, remove algae with Tikkurila Huoltopesu (Maintenance Cleaner) according to instructions on the label, and rinse thoroughly.

If Tikkurila Huoltopesu fails to remove the algae or if the surface has been repainted, wash the infected areas with Tikkurila Homeenpoisto, rinse thoroughly and allow to dry (see Mould).

Apply primer to the clean wooden surfaces. Finish with a suitable Tikkurila exterior paint according to instructions.