Black stains on an asphalt roof caused by algae. … Though often attributed to an accumulation of dirt, defective shingles, mold, or mildew; the most common culprit is actually a blue-green algae known as Gloeocapsa Magma that is spread by airborne spores.
What causes black stains on roof shingles?
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. The algae feed on the limestone in shingles.
What do dark spots on roof mean?
It’s not mold. It’s probably not soot. The black spots discoloring your asphalt roof are more than likely the pervasive and prevalent algae known as Gloecapsa Magma. These roof-invaders require a moisture-rich environment, usually supplied by dew and shade.
What is the best cleaner for roof shingles?
of laundry strength liquid chlorine bleach and water. This is the best way to clean a roof if you have asphalt shingles. After spraying the roof with the mixture, allow it to sit on the surface for 15 to 20 minutes before rinsing thoroughly with clean water.
Will bleach damage asphalt shingles?
Algae creates ugly black or brown streaks but doesn’t damage a roof. Moss — which is what shows in the pictures you sent — is more worrisome because it can damage asphalt shingles. … The bleach will kill the algae or moss, but rinsing won’t necessarily leave the roof sparkling clean.
How do you remove stains from roof shingles?
A mixture of trisodium phosphate (TSP), bleach, and water will also remove stains. Oxygen bleach lightens stains as well and is less harmful to the environment, but it doesn’t produce as immediate or dramatic an effect as chlorine bleach. Roof cleaned with oxygen bleach (left) and chlorine bleach (center).
How do you remove black algae from roof shingles?
The less expensive solution is to spray wash the roof with a 50 percent mix of water and bleach to get rid of the algae. (No pressure washers, please. They’re likely to damage the shingles.) Just be sure to wet your foundation plantings first, and rinse everything in clean water when you’re done.
How much does it cost to clean roof?
Cleaning a roof costs $295 and $592, or $432 on average. Expect to pay between $0.20 and $0.60 per square foot. Regular roof cleaning makes it last longer and improves your curb appeal.
Will vinegar hurt roof shingles?
A: The insurer should have told you that moss on the roof can cause the shingles to decay, but that will take a long, long time. … Yes, vinegar will kill the plants, because vinegar is like acid rain, which can damage any green living thing. Bleach will also kill it.
Can you power wash roof shingles?
NEVER aim your pressure washer up the roof, as it can push water under the shingles. Spraying water under your shingles can both tear off the shingles and force water under them and into your home. Cover a few shingles at a time, and move the wand slightly closer to the surface as more power is needed.
Does Spray and forget work on roofs?
A: Spray & Forget will not work to remove dirt, pollen, sap, or soot, but is very effective on roof moss. … A: Yes, Spray & Forget will work on almost any exterior surface and actually works faster on these surfaces then on roof surfaces. Apply 5 gallons of water to 1 gallon of Spray & Forget mixture to these surfaces.
What is the best way to clean asphalt shingles?
The most effective method of cleaning algae and moss from a roof is with a 50:50 mix of laundry strength liquid chlorine bleach and water. Apply with a sprayer and allow the solution to dwell on the roof surface for 15 to 20 minutes, and then rinse thoroughly with low pressure water.
What is better wet and forget or spray and forget?
The concentration that the wet and forget companies use in their products are slow to kill mold, lichen, moss, and fungi. Spray & Forget, on the other hand, uses sodium hypochlorite which is completely a different composition and is also widely popular due to its effectiveness.
Can you clean roof shingles with bleach?
Mix equal parts of bleach and water in the ratio of 50:50 to form a bleach cleaning solution. … Climb the roof using a ladder and spray the shingles with the solution. Leave the solution on the surface of the roof shingles for 15 to 20 minutes. Rinse thoroughly with water.