Black Algae On Siding

Lichen is a complex organism formed by a combination of fungus and algae.

Black algae on siding.

Green stains clean up in 1 2 weeks black stains and moss clean up in 2 or more months. But testing is probably not justified. The combination of the wind and the rain rinses and scrubs your surfaces clean over time. Clean siding without any scrubbing.

The fungus sets its sights on bright areas so that means it will aim for any pale surface that reflects light such as the siding on your house. The black stains on the vinyl siding shown at left may be a fungus or a black agae. Green stainsare almost always the result of algae or moss. Fortunately algae on vinyl siding will not affect the function of your siding or cause it decompose.

By the growth pattern we think this is almost certainly a dark colored algae. A microscopy lab examination of a sample from this surface would be needed to know for sure. Also known as artillery or cannonball fungus sphaerobolus it uses internal water pressure to forcefully fire its spores similar to seeds up to 20 feet away. Usually appearing as a scaly growth it can grow on any type of siding.

Black stainsare usually a sign of mildew algae mold or fungus. Yellow stainsmean you probably have damaged insulation or deteriorating sheathing behind the siding. Wet and forget is as simple as spraying your outdoor surface and leaving it. To prevent stains you will need to clean your siding thoroughly to kill the algae and prevent it from returning.

Black algae can grow there as well as in areas with direct sunlight due to its protective coating. Green algae black mold and moss begin to die off on contact.