Black Marks On Painted Wood Siding Shingles

The iron found in galvanized fasteners as well as some window screens and flashings can cause blue or black stains on cedar.

Black marks on painted wood siding shingles. As the blue green algae accumulate they develop a dark hardened outer coating which results in the black stains you see. Remove black stains from roof shingles to preserve the appearance of your home s roof. The black roof stains are caused by a form of algae that has been around for years typically found in the woods on the north side of trees or on exposed rocks. The problem is that for many years the only semi transparent wood stains on the market were oil based.

These stains don t respond to oxygen bleach. Some tell us it s from spiders. Black mold we have all seen wood sided homes that turned that death black color. The algae will worsen and become more noticeable each year trapping moisture and causing premature shingle aging and granule loss.

But now this black algae is termed a roof shingle algae because of the annoying discoloration on a asphalt shingle roof. It is not uncommon for roof shingles to turn black over time. The algae feed on the limestone in shingles. It just looks bad.

Micro black spots on siding tags. The black streaks running down roofs are actually a hardy algae called gloeocapsa magma. Lawn garden we have thousands of tiny black spots pin head size all over the siding of our house. Black brown or gray stains on roofing products due to debris left on the roof surface such as piles of leaves and organic waste from nearby trees.

Oil based stains actually feed mold. In wooded or shaded areas mold is going to present itself insidiously. When that happens it is generally caused by mildew algae mold or dirt stains. Instead use a wood.

See debris staining and see proximate cause of roof shingle stains.