Black Algae On Siding

To prevent stains you will need to clean your siding thoroughly to kill the algae and prevent it from returning.

Black algae on siding.

Fortunately algae on vinyl siding will not affect the function of your siding or cause it decompose. Black stainsare usually a sign of mildew algae mold or fungus. A microscopy lab examination of a sample from this surface would be needed to know for sure. Lichen is a complex organism formed by a combination of fungus and algae.

But testing is probably not justified. Yellow stainsmean you probably have damaged insulation or deteriorating sheathing behind the siding. By the growth pattern we think this is almost certainly a dark colored algae. Wet and forget is as simple as spraying your outdoor surface and leaving it.

Black algae can grow there as well as in areas with direct sunlight due to its protective coating. The black stains on the vinyl siding shown at left may be a fungus or a black agae. Clean siding without any scrubbing. Will algae harm your siding.

Green stainsare almost always the result of algae or moss. 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. You re most likely to see green stains on siding that is inadequately ventilated.

However if the algae is left to flourish it could permanently stain lighter colored siding with unsightly green brown or black spots. The combination of the wind and the rain rinses and scrubs your surfaces clean over time.