White Shingle Roof Algae Stains

To remove the existing stains you need to use a safe cleaning solution.

White shingle roof algae stains.

Many of these shingles are guaranteed to kill the algae for the life of the shingle. When that happens it is generally caused by mildew algae mold or dirt stains. So it pays to clean your shingles as soon as you spot algae growth. It is not uncommon for roof shingles to turn black over time.

Roofing manufacturers have tackled the problem of roof algae by creating shingles containing copper which is deadly to algae. White stains on wood shingle roofs. The white stains shown on this wood shingle roof are in fact not a stain but an absence of lichens or moss. Roof shingles are exposed to a lot of wear and tear as extreme heat sun wind and precipitation come into contact with them.

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. Algae lichens and moss for example. Using shingles that have been treated with algicide keeps the growth at bay for about 10 years thus the 10 year algae warranty. 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.

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. 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.