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Can Moss Grow on Metal Roofs?

August 18, 2019 by ROTban Services Corp.
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Metal roofing is strong and durable, providing many benefits when compared to other roofing options. However, even with how strong and durable it is, the surface can still be damaged from moss growing on it, and algae too.  Yes, even metal roofs are susceptible to these growths.  Metal roofs can quickly look dingy and blah.  Fortunately, there are some ways to prevent the these from growing as part of regular roof maintenance, and a full metal roof cleaning is an option.

How does Moss Grow on a Metal Roof?

Moss begins its life as a spore. These are carried by the wind, or even birds, and can land anywhere, including your metal roof. Moss attaches itself to any organic material that is available, and uses this as its anchor, or base, for growing. Often on a metal roof, the organic material that moss attaches to is pollen from nearby trees, decomposing leaves or even bird droppings. Amazingly, you can see this happening on metal that seems to have no dirt on it.  Notice old cars sitting in the shade, and how stained they are.

Can Moss Damage a Metal Roof?

Moss may seem harmless, but the feeding action from it can actually cause significant damage to a metal roof. Moss has excellent moisture retention, meaning it is constantly damp from rain and slow to dry out. This water is then trapped against the metal roofing. As we all know, water corrodes metal, and overtime this damage can become more serious. The water and digestive material can also discolour and stain the roof, making it unsightly once the moss and algae is eventually cleaned off, unless it’s sterilized.

How can I protect my roof?

The main thing is to get a professional for a thorough metal roof cleaning. This will remove any moss that is present, as well as any organic matter that may be on the roof. After it has been cleaned, the roof can be inspected to determine the extent of the damage, and if any repairs are needed. Once this is completed, you will want to make sure that you do regular roof maintenance and keep it clean. But are the professionals really up to date in their methods?  What about walking on the metal?  Is that good?

A more practical option is to have your metal roof cleaned with ROTban™ Sterilization System. ROTban is able to thoroughly clear and remove all the moss and algae from your metal roof, and provide a protective environment, without damaging your roof. This protection has been shown to last for at least 4 years, preventing new moss growth. ROTban reduces the need for constant roof maintenance.