Why Does My Roof Have Black Streaks

While the dark streaks are unsightly experts tell our team that the greatest danger to the roof is from moisture retention or root damage that algae and other life forms can cause.

Why does my roof have black streaks.

It can happen to homes that are otherwise maintained very well but why. A contagious roof algae is responsible for those black streaks on your roof. The algae feed on the limestone in shingles. This isn t unique to abandoned houses either.

Although these dark spots and ugly black streaks on your roof may look like dirt mildew soot or mold what they really are is algae. When decayed the algae turn black. The algae have a weakness and it s the copper and zinc coating used on the sheet of metal flashing which is toxic and kills the growth. Black streaks on shingles aren t caused by leaking tar.

Near the metal flashing that s around chimneys and roof vents. Almost without fail every photo of an abandoned house would have black streaks on roof shingles. Rather they are caused by a hardy algae known as. Learn how to remove them and how to prevent them.

This algae growth usually begins as small spots and then eventually becomes visible streaks. If you look even closer you re bound to notice that the black streaks are everywhere but one place in particular. The algae will worsen and become more noticeable each year trapping moisture and causing premature shingle aging and granule loss.