How Mold and Mildew Grow
Learn the invasive growth habits of fungus, the "enemy."
Mold grows via spores to form mycelia. Like roots, these mycelia penetrate paint and may reach into the wood surface below. To the highest degree possible, the fungicide must reach beneath the immediate surface.
Understand why the best tool to accomplish the job may not be the right one.
Mercury preparations (such as phenyl mercuric compounds or mercuric acetate) make excellent fungicides; however, due to health and environmental concerns, less efficacious substances must be chosen for use in paint, especially for indoor surfaces. Mercury can invade the body through ingestion, skin absorption, or inhalation in trace quantities (causing acrodynia, a rare disease that causes painful extremities). Mercury is concentrated in the tissues of the nervous system and in red blood cells.
Heavy metals have been largely supplanted by proprietary organic formulations.
Maintain your investment. Periodically check painted surfaces to see if mold and mildew removal is needed.
Though fungicides are compounded in quality latex paints, protection against mold and mildew does not last forever. Cool, damp, and shady locations will hasten the growth of mold and mildew. Painted surfaces will require external application of cleaning/fungicidal agents. There are proprietary formulations (often expensive) that can be purchased to remove mold and mildew, however it is possible to formulate your own fungicide using the following ingredients:
1/2 cup of 5% chlorine bleach 1/4 cup laundry detergent 1 gallon water
Once applied, let the formulation sit on the surface for about 5 minutes before rinsing. If using a power washer (for outdoor painted surfaces), do not apply too much pressure, as this can cause paint to chip or peel.
Things You Will Need
- Household bleach
- Household detergent
- Power washer (optional)
- Some prefer to use Borax, rather than bleach plus detergent. Follow safety precautions and use in a manner consistent with labeling instructions.