Why Algae is Roof Poison

Your roof is the shield for your home. It collects dirt and leaves. But if you don’t watch things you can get a huge enemy! ALGAE! Your roof can slowly become covered in algae, fungus, lichens, and bacteria. There is no such thing as “roof mold” so if someone tells you it is normal they are wrong. The most common thing is a blue-green algae that leaves dark nasty streaks on your roof.

The stains will worsen year after you until you invest in professional cleaning. If your roof is already covered in streaks and algae call All About Roofs to have a professional cleaning done. If your roof is new you can clean it yourself on a yearly basis or have us do it if you do not feel comfortable doing the job yourself.


What Does it Look Like?


Recognizing it will take practice but if you see discoloration to the roofing materials like black stains or streaks or a big mass of green moss on the roof then you have a problem. It can also be patchy in clumps like a mold on bread. Lichens appear like round spots. Mosses look just like they do in a shady part of your yard or forest.  Green mosses tend to spread slowly.

Any vegetative growth on your roof also makes your home look neglected and reduces your property value and curb appeal.

Why is this Happening?

Roof algaes develop and thrive in certain conditions. This is moistly hot and moist. Here in Wiregrass we have plenty of both. Algae grows very quickly in damp and shady areas. If you have a large tree shading part of your roof then you have the perfect environment for algae to bloom.

FUN FACT: the limestone in asphalt shingles provides the nutrients to algae sports.

Algae blows in the wind as a spore and all it takes is a single spore to land on your roof for an algae bloom to start. Keep your gutters clean and trim back branches as much as possible to limit the happy environment algae needs.

Roof Bacteria, Lichens, Algae and Mold

Roof bacteria are common. There are many different types. You may have bacteria, moss, or mold. Roof algae is usually black-green or black-blue. Gloeocapsa Magma is a common roof bacterium that lives on water and produces oxygen. It usually stains black on your roof and the stains actually protect the bacteria from being killed! Ingenious little things indeed!

Roof lichen is a combination of both algae and some fungus. They live in a symbiotic relationship. Lichens use roots to secure themselves to your shingles which can result in them removing the top layer of your shingles. It is extremely important to get ahead of lichen before it causes granular loss or even worse shingle failure. The roots can permanently disfigure your roof causing lasting cosmetic and structural damage. The roots are call rhizoids and they can actually harbor even more stain producing bacteria by protecting it from sunlight which dries it out and retaining moisture which fuels it.

Mold is never a healthy thing to have around. Roof mold is usually blotchy and grows in clusters. It stinks and is often slimy. Mold is a sign your roof has a water absorption problem and should be handled immediately. 

Mildew is like mold. It grows on damp surfaces and looks powdery. It can be a lot of different colors from black to pink.

All of these things pose a risk not only to your investment in your roof but to your family’s health. Call us immediately.

8 Negative Affects of Roof Growths

  1. Degraded Appearance Most people don’t even know they have a problem until they have ugly black streaks, mossy fuzz, powdery white stains, spots, or some other cosmetic defect. This reduces curb appeal and makes your home seem unmaintained.
  2. Home Value If you’re trying to sell your home algae is not something they want to see. It makes it seem like your home is not well maintained. They will automatically assume your roof needs to be replaced.
  3. Damage to Other Structures Mold and Algae travel on the wind and if you have a secondary structure like a garage on your property you are leaving it at risk for contamination and the problem will just spread around.
  4. Decking and Wood Rot Moisture that penetrates your roof can cause severe problems and permanently compromise the strength and safety of your roof. This can lead to leaks, mold, and the need for a complete replacement.
  5. Roof Integrity Allowing an algae, lichen or mold situation to overtake your roof can limit the lifespan of your roof by years.
  6. Health Risk Roof mold or algae can damage the health of you and your family. You do not want to breathe in dangerous bacteria while in your home or yes, even your yard. The sooner you deal with any problems the better. Don’t worry we’re here for you!