Have you always wondered what those black roof stains are and what is causing them to appear on your roof?
Most homeowners assume something has failed and the shingle's granules have fallen off fortunately that is not true.The black stains on your roof is a form off algae called (Gloeocapsa Magma) this roof algae is spread by wind and animals and can't be prevented, it has been a problem in the southern United States and now has traveled into parts of Canada, cold and freezing temperature's will not stop the growth of this type of roof algae in Canada, this roof algae feeds off the limestone filler that is put in the shingle's, so every time it rains the algae runs down the roof and over time it will causes those black streaks you see on your roof.
Can The Black Stains Be Removed?
The answer is YES at Durham Roof Cleaning we can remove those ugly black roof stains at a fraction of the cost of a roof replacement, some homeowners are replacing there roof because of these black roof stains and do not know that it can be removed when there roof still has life left.We use a safe non-pressure roof cleaning method that the Canadian Asphalt Shingle Manufacturer's Association (C.A.S.M.A.) recommends.
Lichen (Grey Moss)
In the picture above the roof was covered in Gloeocapsa Magma and Lichen you see the white streaks this is dead Lichen, after are roof treatment this grey moss will go white and then turn brown this will come off in time with a few good rain falls or it can be rinsed off with a garden hose. ( Extra for rinsing.)
There is certainly a lot of misconception involved with the topic of roof cleaning. Can you clean an asphalt shingle roof? Can you clean a roof without harming the shingles? What are the black stains on my roof? What will happen if I don't get the roof cleaned? These are just a few of the questions this article will answer. Knowing this information can save you costly future roof replacements and added heating and cooling cost..
What Are Those Black Roof Stains On My Roof?
In many regions across the United States and Canada roof algae (Gloeocapsa Magma) is a growing problem. The algae thrives in warm humid climates, usually first appearing on the north facing slopes of your roof where the right amount of shade and moisture are common. With the proper atmosphere the algae only needs one more element to survive and that's food.
Roof Algae feeds on the crushed limestone filler that is used in the manufacturing of asphalt shingles.When shingles where first produced manufacturers quickly realized they where to light and would not provide adequate protection, so they added crushed limestone to the asphalt to add weight and durability to the shingles.
Gloeocapsa Magma is an airborne algae so it can land on any roof with no rhyme or reason, though it does seem to be more prominent in areas holding a lot of trees. Once the roof algae lands on the roof it will have to be killed and removed properly or it will continue to spread, it will never get better or just go away on its own. The algae begins feeding on the nutrients in the shingles, as it rains it is spread down the roof causing black streaks. If not taken care of it will take over the entire roof in a few short years turning the whole roof black.
Besides looking very unsightly and diminishing any home's curb appeal and value, what other damage can roof algae do? When roof algae is not taken care of they stop the shingles from reflecting heat from the sun's UV rays. When this happens it can affect your home's heating and cooling costs without you even realizing it. Also because the shingles cannot reflect heat they start to diminish prematurely. Signs of wear are curled corners, wavy or humped shingles, broke or loose shingles, and an excess of shingle granules appearing in your gutters just to name a few.
Most home owners become concerned when the first unsightly black streaks begin to appear long before permanent damage is done. It's at this point that most home owners will call a roofing contractor and in my opinion it's the point where home owners are steered in the wrong direction.
It has been my experience from talking with many troubled home owners that most and I express the word "most" roofing contractors are not going to tell the home owner that their roof only needs to be cleaned. Think about that for a moment, why would they? I have had many customers tell me that a roofing contractor told them that the black streaks were water marks or a sign of wear in either case a roof replacement was recommended.
Another scenario is that some roofing contractors have no idea themselves what roof algae is and that it can be cleaned. Some will also combat losing a potential roof replacement job by telling the home owner that you can't clean shingles without damaging them, which is completely untrue. None the less many home owners are suckered into a costly, premature roof replacement of a roof that only needed cleaned. If you think about it, it is no different than replacing your vinyl siding because it has mold or mildew on it, no one would think of doing that.
The good news is that shingles can be cleaned properly without harming the shingles, and the major shingle manufacturers say so themselves. They even have suggestions and guidelines for cleaning roof algae off of asphalt shingles without harming them. http://www.casma.ca/en/bulletin_13.shtml The proper methods include a low pressure chemical application followed by a light rinsing. NOTE: never use or allow a pressure washer to be used on your roof.
Inexperienced home owners and unethical contractors have damaged shingles by attempting to blast the algae off the shingles using high water pressure. Doing this blows the shingle granules off which are there to protect the shingles, thus lessening the longevity of the roof.
In the past some have tried zinc strips on the peak of the roof which are suppose to release chemicals down the roof when it rains to help combat roof algae. Most have reported poor results with the strips. Recently shingle manufacturers have produced algae resistant shingles but there have been plenty of cases of roof algae still invading such shingles. This is why they can only call them "algae resistant" and not algae proof.
If you are battling with roof algae or know of someone else whom is don't lose hope and don't replace that roof prematurely.
