The solution might involve anything from waterproofing the roof to pruning the trees in your yard.
What causes dark stains on roof.
Commonly found in climates with warm humid summers it does no damage to the roofing but it certainly does looks bad.
Rust or chimney soot stains red or brown rust stains around chimneys is a common roof stain.
Roof leaks are the main cause of water stains on the ceiling.
The most common type is known as gloeocapsa magma also known as blue green algae.
It is most widespread in the eastern united states and is commonly found on roofs with northern exposure.
As the blue green algae accumulate they develop a dark hardened outer coating which results in the black stains you see.
Once stains redevelope and stay then it s time to recoat the entire roof since this dark algae can develope anywhere upon it.
The black streaks running down roofs are actually a hardy algae called gloeocapsa magma.
The algae feed off of the limestone within the roof shingles.
Here is a diagnostic guide to types of stains and staining materials found on roof surfaces black red green brown or other coloured stains on asphalt roof shingles or on other roofing materials need first an accurate diagnosis of the stain cause and then proper steps to remove the stain or to prevent future staining on roof shingles surfaces.
This job goes much faster if you can borrow or rent a 12 volt diaphram garden sprayer with a large tank and a slew of hose preferably on a reel be sure to wear rubber boots plus gloves and stay upwind while applying.
Here are some clues to follow.
If your household water pressure isn t enough to generate the proper nozzle pressure at the jets the manufacturer recommends boosting it.
To identify a roof leak you should look for the obvious factors like missing or damaged shingles roof tiles torn flashings or loose screws on the exterior of the roof.
The algae feed on the limestone in shingles.
Quite a few other issues can cause stains on a roof.
The black mold like stains and streaks that appear on roofs particularly light colored asphalt shingles is actually a blue green algae gloeocapsa magma.
Over time this algae accumulates developing a black outer coating which causes stains on roof shingles.
Once you identify the leak have someone fix it before you intend to remove the water stains so that the stains do.
Dark streaks or roof discoloration caused by algae happens in varying degrees across the u s especially in areas exposed to warm humid conditions.
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.
Other causes of roof discoloration.