Roof cleaning – removing black algae stains on roofs

removing black algae stains on roofs by Bluewhale Powerwash in Charlotte

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If you’ve noticed black stains and streaks on your roof, you should look into hiring a professional roof cleaning company to have them removed.  Aside from fallen debris (leaves, branches, dirt, etc…) that can accumulate on your roof, bacteria and fungi can also proliferate on your roof covering, especially in the Charlotte area where moisture and a warmer climate create the perfect environment for algae ( gloeocapsa magma ), fungi, moss and lichens to grow and spread. Bacteria and fungi growths will make your roof look old and neglected, negatively affect curb appeal and the perceived value of your home,  and worst, compromise your roof structural integrity and shorten its lifespan. Organics such as algae can grow on all types of roof coverings including asphalt shingles, metal roofs, concrete and tile roofs.

Types of organic growths found on roofs in and around Charlotte

Algae – gloeocapsa magma

If you have dark streaks and smudges on your roof, it is caused by gloeocapsa magma, a type of algae that is very common in the Charlotte area. We see it all the time on residential and commercial roofs.  This type of algae causes unsightly stains that won’t resolve on their own and will keep spreading until properly treated. Gloeocapsa magma feeds on the lining of shingles, erodes shingle granules in the process and shortens the life of the roof covering. This kind of algae shows up as vertical black and brown stains and smears, usually starting on the north side of the roof. 


Moss grows where there is moisture and shade. It usually starts growing on north-facing surfaces. While some people might like the organic look of moss on their roof, it is problematic with shingle and tile roofs. Moss is a wet plant that accumulates moisture as it grows in size. It allows for constant moisture to touch the roof. Moss can grow to a substantial size and weight as it sucks up moisture. Overtime time, it can move shingles and tiles away from their original position, creating gaps that allow moisture to infiltrate below the outer layer of the roof, causing wood decay and a host of other issues overtime. It also adds weight to the roof structure, which could in extreme cases, lead to a roof caving in.


Lichens on a roof (and other surfaces) show up as spot-growths ranging in color from light green to yellow and gray. Lichens can tarnish the neat appearance of a roof. Like moss, lichens hold moisture in place against roof coverings, speeding up the normal wear and tear. When it freezes likes it does in the Charlotte area, lichens can cause frost damage to shingles and make them bend, warp or even even cause separation between shingles.

Learn more about organic growth on roofs.

roof cleaning mossy roof in Charlotte before Roof cleaning mossy roof in Charlotte after treatment results
This an example of a roof cleaning treatment performed by Bluewhale Powerwash near Charlotte. This roof had a substantial amount of algae, moss and lichen growths. Our safe roof cleaning treatment using the soft washing method drastically improved the roof condition and curb appeal of the property.

How can bacteria and fungi growing on your roof affect your property?

Starting with the obvious, bacteria and fungi growing on your roof will affect your property’s curb appeal. Roof discolorations make your roof (and your home) look old and neglected, hence affecting perceived value. This can really be problematic if you are selling your home. To get top dollars for your home, making sure your roof and exterior surfaces are clean will make your home more attractive and desirable to prospective buyers, driving higher offers and reducing buyer concessions for repairs and improvements. Bluewhale Powerwash offers pre-listing pressure washing and soft washing services to make sure your home looks its best when you decide to put it up for sale. 

Organic growths can also cause substantial structural damage to your roof because they hold moisture and can compromise your roof’s ability to repel water by causing shingles to move or warp allowing moisture to seep in and rot wood materials. Organic growths can also attract insects and cause mold infestation.

Charlotte algae roof treatment before Charlotte algae removal roof treatment after

Roof cleaning treatment - how we safely remove organic growths from roofs

Removing organic growths from a roof is an involved process that requires the right equipment, cleaning solutions and the right techniques. Our roof cleaning treatment is safe and yield great results. We use the soft wash cleaning method to apply our cleaning solution to treat algae, fungi, bacteria, moss and lichens. Once applied, we do not rinse the roof unless it is a metal roof or if a home does not have gutters. The sun and rainwater will over time and naturally deactivate our cleaning solution leaving your roof clean and looking fantastic. Before, during and after the roof cleaning treatment, we follow a vegetation protocol to protect your flowers, shrubs and trees during the treatment.

If you live in or near Charlotte and your roof has algae, moss or other organic growths, contact Bluewhale Powerwash at (704) 272-4726 to request a free estimate. We respond to inquiries the same day they are received during business hours or the next business day if received after hours. View some of our most recent work on our Facebook page.

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Bluewhale Powerwash service areas

Bluewhale Powerwash is proud to offer its professional pressure washing and soft washing services to homeowners and businesses in Charlotte and nearby areas. We also serve smaller towns located close to larger ones. If your town is not listed below, please contact Bluewhale Powerwash to find out if we can service your area.

Bluewhale Powerwash, LLC

317 Matthews Mint Hill Road
Ste 201
Matthews, NC 28105

Business Hours
Monday 8:00 AM - 5:00 PM
Tuesday 8:00 AM - 5:00 PM
Wednesday 8:00 AM - 5:00 PM
Thursday 8:00 AM - 5:00 PM
Friday 8:00 AM - 5:00 PM
Saturday 8:00 AM - 5:00 PM
Sunday Closed

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