White Shingle Roof Algae Stains

Algae lichens and moss for example.

White shingle roof algae stains.

I covered our asphalt shingle roof about five years ago with white 50 year guaranteed shingles that had algae prevention treatment but now the entire north side of our roof is black with algae i bought the shingles from lowe s in marianna florida. It is not uncommon for roof shingles to turn black over time. Replacing the shingles on your roof just because you have black stains is not necessary however and you should be suspicious of any roofer that suggests roof shingle replacement as the only solution to your algae problem. Roof shingles are exposed to a lot of wear and tear as extreme heat sun wind and precipitation come into contact with them.

Algae is more likely to grow on shaded roof sections probably the cause of black stains on the lower roof in the photo at above right while asphalt shingle bleed through stains more often appear to emanate from single points regardless of sun or shade exposure probably the cause of stains in the photo at above left. When that happens it is generally caused by mildew algae mold or dirt stains. Do it yourself and save big bucks. Believe it or not there are several treated wood deck cleaners that will do the job without hurting you the roof your gutters and any vegetation below.

To remove the existing stains you need to use a safe cleaning solution. Using shingles that have been treated with algicide keeps the growth at bay for about 10 years thus the 10 year algae warranty. But once the algicide wears off your roof hosts an all you can eat buffet for the neighborhood algae spores. White stains on wood shingle roofs.

Metal salts washing down the roof surface from metal chimney flashing are often enough to kill of biological organisms that otherwise stain various roof surfaces. So it pays to clean your shingles as soon as you spot algae growth.