Black Marks On Painted Wood Siding Shingles

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.

Black marks on painted wood siding shingles.

When that happens it is generally caused by mildew algae mold or dirt stains. Instead use a wood. Oil based stains actually feed mold. Others have said it s a.

These stains don t respond to oxygen bleach. These black streaks are unsightly and can diminish the appearance of the entire exterior of the home. Some tell us it s from spiders. See debris staining and see proximate cause of roof shingle stains.

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. Remove black stains from roof shingles to preserve the appearance of your home s roof. Lawn garden we have thousands of tiny black spots pin head size all over the siding of our house. It is not uncommon for roof shingles to turn black over time.

The problem is that for many years the only semi transparent wood stains on the market were oil based. It just looks bad. But now this black algae is termed a roof shingle algae because of the annoying discoloration on a asphalt shingle roof. The iron found in galvanized fasteners as well as some window screens and flashings can cause blue or black stains on cedar.

Black stains on vinyl or painted building exterior wall siding may also be mold as our photo shows at above right. The algae will worsen and become more noticeable each year trapping moisture and causing premature shingle aging and granule loss. The black streaks running down roofs are actually a hardy algae called gloeocapsa magma. As the blue green algae accumulate they develop a dark hardened outer coating which results in the black stains you see.

Micro black spots on siding tags.