What’s Eating Your Roof?

Learn about the natural threats to your roof  today (algae, lichen, moss) so you avoid time-consuming, costly repairs and replacements tomorrow.

Airborne algae causes the BLACK STREAKS on your roof.  Air currents carry the spores to all surfaces. GREEN GROWTH on your roof is one of two organisms, a moss or a lichen. 

All of these growing organisms destroy your shingles, as well as, collectively reduce the expected life of your most expensive single component of your home, your roof.  

Therefore, insurance carriers insist that any buildup of growth is promptly removed from the roof surface. Our recommended and approved process satisfies insurance carriers’ requirements for your roof.


The black “stains” on your roof are actually large colonies of airborne algae called Gloeocapsa Magma (Cyanobacteria). They affix themselves and eat away at the limestone filler found in shingles. As they eat and grow, they readily reproduce into more algae. Eventually billions of individual alga cover the entire roof surface; destruction to your roof system will gradually occur over time, potentially leading to premature replacement of your roof.  Here is the science behind the infestation Microbe Wikipedia .


A lichen is an organism that evolves from the algae, Gloeocapsa Magma. Lichens attach themselves very securely to the shingle, consequently, wind, rain or snow will not dislodge them. 

As a result, if left untreated, they forcibly remove the top layer of the shingle, the color coat, and will permanently scar the shingle surface.


Mosses have root-like appendages called rhizoids, which drive into the shingle to anchor themselves onto the roof. The mosses consequently build a thicker layer of soil by catching windblown dirt in their interlocking system of roots and upraised stems. As a result, the accumulation of soil facilitates both algae and lichen growth, and make possible the evolution of higher plants with real roots. Because mosses anchor themselves onto the shingles forcible removal causes permanent damage and will greatly speed up the need for roof replacement.

Frequently Asked Questions

Q. What are those black stains on my roof?
A. Those UGLY and DAMAGING roof stains (often erroneously thought of as roof mold, tree sap or even acid rain) are a very hardy algae called Gloeocapsa Magma. The algae thrive on the moisture on your roof and the limestone in your shingles. As a result, your whole roof becomes completely discolored as the algae multiply.

Q. Can the algae on my roof shingles damage my roof?
A. ABSOLUTELY! Algae feed on the limestone filler used to give the shingles weight. Over time, as the filler is eaten away, the granules protecting the surface of the shingle lose their hold and begin to wash off. As a result of this loss of shingle mass, the roof loses the ability to reflect heat rays. By not efficiently reflecting light from the sun, the roof gets much hotter than it should. The increased heat leads to shortened shingle-life, as well as increased heat in your attic, possibly causing higher air conditioning bills.

 Q. Is there anything else that might be growing on my roof and staining it?
A. DEFINITELY! Moss and lichens also love growing on roofs. Lichens evolve from the algae. They act like sponges, keeping the roof damp and causing even more growth. Roof moss and lichens anchor their “roots” into your shingles and remove granules.  In addition, their roots can fracture shingles or expose edges. Moss and lichens cause shingles to fail many years sooner than their 20 to 30 years of expected service.

Q. What can I do about it?
A. You can contact Softwash Hawaii! Instead of just pushing the algae, moss, and lichens off your roof with pressure washing (which can actually cause even more roof damage), our specially designed cleansing solutions kill algae, moss, lichens and other types of organic contaminants while protecting your family, pets, and the environment. It all starts with a thorough inspection.

Q. Will pressure washing really harm my roof?
A. YES! Just blasting away with a pressure washer can destroy your roof – and still not kill the algae in the shingles! Pressure washing roof shingles dislodges the protective granules from the shingle surface and consequently causes scarring. In the hands of an inexperienced operator, a pressure washer can even blow shingles right off your roof!  

In addition, it does NOT solve the root cause of the stains — algae growing and feeding on the limestone/slate/wood/minerals in the shingle.

Softwash Hawaii uses non-hazardous, water-based, specifically designed cleansing solutions that have been used for decades on thousands of roofs. Our application method has less pressure than a garden hose. Every major shingle manufacturer in the U.S. recommends a low-pressure wash.  Therefore all of our methods and techniques applied to your building are approved by ARMA — the American Roofing Manufacturers Association.

Q. How much will it cost me to hire Softwash Hawaii to eliminate algae, moss, lichens and other roof-destroying organisms from my roof and exterior surfaces?
A. Short answer — a small percentage of buying a new roof! Roof replacement can cost 10-20 times our treatment cost.

Nationally, the #1 reason most roofs are replaced is because they look dirty all the time. But they’re NOT worn out … they may still have a decade or two of life in them. This “dirt” is really the Gloeocapsa Magma algae living, breeding, and dying.  Be aware, if you replace your roof, and you live in a neighborhood where other roofs are infested with Gloeocapsa Magma, your roof stands a very good chance of being infested in just a few short years. The wind transfers the algae spores.  When the company was started, the average age of roofs with noticeable growth was between 10-14 years.  Now we are noticing many customers with 4-8 year old roofs that are covered with growth.  This is despite the increased manufacture of algae resistant shingles.  The spores are everywhere and they are growing fast.

We base our pricing on several factors, including but not limited to:

  • the size of the roof area to be cleaned
  • the number of stories (how high)
  • the pitch and complexity of the roof
  • the presence of moss and / or lichens
  • and the driving distance to the job

As a result, we custom-quote every job to keep our prices low for every homeowner.   

Locally in Hawaii, costs range between $0.29 -$0.41 per square foot of area treated.  

The variance in pricing includes items such as: 

  • severity of growth and type of growth
  • difficulty of treatment
  • safety measures/equipment needed
  • guarantees (thoroughness of treatment) offered
  • method of cleaning, etc.   

We do not cut corners with quality, safety or methods.   

Contact Softwash Hawaii FREE estimate today!

Q. Will the roof cleaning products hurt landscaping or pets?
A. No. Our biodegradable cleaners are, correctly handled and applied hence, safe for grass, shrubs, pets, and people. Also, they contain no solvents, phosphates, peroxides, or other harsh chemicals in high concentrations. In addition, our rigorously trained technicians know how to safely treat your home.

Q. How long does a roof cleaning last?
A. Our cleaning agents produce great results that we guarantee will last for two years. 

Q. Can you just clean off the few light streaks or just the front roof?  I don’t think my whole roof needs cleaned.
A. Spot cleaning is ineffective.  The minor stains or streaks on a roof indicate that an entire face of the roof is infected with algae.  

Q. What types of roof can you clean?
A. We clean (but are not limited to) asphalt shingle, slate, tile, wood shake and metal roofs.

Q. I’ve seen D-I-Y roof cleaning products on the Web. Are they any good?
A. There are roof cleaning products available online. Each has different chemical solutions with various application methods and precautions to consider, furthermore, need to buy or rent the tools, pumps, or sprayers to apply the chemicals. Our experience has shown that the “guaranteed” results promised by these products are almost always less than satisfactory. We have talked too many customers who have tried these products with little success. These products frustrated us, therefore we feel they will frustrate you. (Softwash Hawaii was started due to a DIY project gone bad)

Before you consider a do-it-yourself effort, remember that cleaning your roof is hazardous! We use a variety of required safety equipment to protect ourselves and your property from harm. Our goal is to rid your roof of algae and other damaging organisms in the least expensive, most effective, safest way possible.

Q. Are you insured?
A. Yes, we are fully insured.  

Q. When can you start?
A. As soon as you contact us! Get a Complimentary property walk-through and estimate.

Share This Post

You're In Good Hands!

We want you to know
We are committed to your happiness



& Insured




Oahu’s #1 Trusted Soft Washing & Pressure Washing Company

Ready to restore The Look of your Home?

no obligations just a fast quote



Use Code [ 25-OFF ] When Requesting a Quote for Two or More Services