Mildew

 

Small fungus growth, usually black, which appears on coating surfaces.

Small fungus growth, usually black, which appears on coating surfaces.

Causes

  1. Continuous high humidity. The critical point of relative humidity is about 75%. The higher the humidity level, the fastest the mildew growth.
  2. Coating or sealant applied over a contaminated surface from which mildew has not been completely removed.
  3. Exposure to conditions favouring mildew: humidity, absence of light, contact with food or fermented drink (beer).
  4. Interior coatings used outside.
  5. Water infiltration.

Solutions

  1. Consider installing proper ventilating system. Clean surface properly with a household bleach solution and paint again.
  2. Clean surface and remove coating or sealant by sanding, scraping or striping surfaces. Clean surface with a household bleach solution and repaint or apply the new sealant.
  3. Clean surface on a regular basis with a household bleach solution or choose a mildew resistant coating.
  4. Clean surface with a household bleach solution and repaint. Choose a paint containing fungicides.
  5. Check sealants’ water resistance.
  • Solvent-based products usually offer a very good resistance to mildew. If you wish to
  • apply a water-based product in high moisture areas, use a coating containing fungicides (kitchens and bathrooms paint).
  • To eliminate fungus growth causing mildew, use household bleach.
  • If mildew develops under coating, strip and clean surfaces with a household bleach solution before repainting.
  • The same recommendations apply in the case of algae growth.