Algae and Mold Prevention on Vinyl Siding

Cultural Prevention

• Making changes around your home's exterior can help prevent mold and algae from growing on your vinyl siding. If the branches of a nearby tree shade the side of your house, trim them back. This allows sunlight to reach the siding and inhibits mold growth. Mold and algae thrive in moist environments, so redirect sprinklers that splash water onto your siding. A leaking gutter can provide them with the water they need, so repair any leaks above a problem area on the side of your house.

Vinegar

• If mold or algae have been a regular problem in a particular spot, every other week or so, wash the problem area with a solution of three parts white vinegar to seven parts water. The acetic acid in household vinegar is strong enough to damage organic tissue, including that of fungal growths and algae. This solution will kill mold spores and algae before they have a chance to get established.

Ions

• If washing your house down a couple times a month isn't an option but mold and algae continue to return, install copper or zinc strips along the topmost vinyl sections of your siding. Most commonly used to prevent fungal growth on roofs, copper and zinc strips release ions every time they are exposed to water, like in rainfall. The ions sheet down the side of your home, killing mold spores and algae and creating a protective barrier against their return.

Cleanup

• If mold and algae grow on your vinyl siding despite your precautions, remove them with a mixture of one part bleach, one part laundry detergent and five parts water. Use a long-handled brush dipped in the mixture to scrub away the growth on your siding and rinse the area thoroughly with water. Try to avoid getting the mixture on nearby plants because it can damage them. Once the mold and algae are gone, start using the vinegar mixture to keep your siding growth-free.