Umbrella Property Services - Moss on the roof

What’s That Growing On My Roof

Umbrella Property ServicesHome Care, Pressure Washing Leave a Comment

Got something growing on your roof and not quite sure what to make of it? Here are a few of the would be culprits:

Moss – This is a more common type of growth on roofs. Moss is darker green, thick, holds more water, and grips into the surface of the shingles.

Lichen – Lichen is a combination of algae and fungus and usually has a light, mint-green color. It doesn’t trap as much water against the surface of the roof as moss, but it can be acidic and has strands that can penetrate into the shingles.

Algae – The third most common type of growth on a roof is algae. It doesn’t have the thick growth like moss and lichen and it looks like stains on a roof, usually in streaks of black or sometimes green. It doesn’t cause any damage to shingles but definitely affects the appearance of your roof, making it look dirty and worn out


If the roof is in good condition and the shingles aren’t worn, it is recommended that moss, lichen and algae be removed and the roof surface be treated and cleaned.

Here are some steps that can be taken to remove that unwanted roof carpet:

Thicker growth will need to be carefully scraped. A wide plastic scraper, used to remove excess wax from snowboards, works well. It’s best to round the sharp corners with a file so that you don’t gouge your shingles

Any remaining or thinner growth can then be treated with a herbicide. There are commercially available products that are specifically for moss, lichen and algae. With any herbicide, bleach or other chemical treatments, be cautious of overspray and runoff that could harm plants.

After the lichen or moss dies off and loses its grip on your shingles, a low-pressure wash, aimed down the slope of the roof, will likely remove the rest of the growth


These things grow where there are enough sunlight, nutrients and water. Algae on roofs is usually an indication that there is a lack of inadequate building practises such as dirty gutters/roof above and poor gutter and/or roof drainage.

Be sure to wash your roof regularly. Also, water from upper gutters should go through a downspout and not over the roof where it will wear on the shingles.

Aesthetics is the chief reason for cleaning algae from roofs. You work hard to showcase your home and to make it a welcome sight at the end of a long day. Don’t let this unsightly growth plague you any longer. The task of removing can be daunting (not to mention potentially dangerous). But take heart, there are professionals that can look after this for you. Why not pick up the phone and give us a call right now?

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