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What Is The Green Stuff On Siding?

Updated: Jun 8, 2020

The green stuff on your siding is more than an eyesore. It is actually airborne algae that can cause long-term damage to the surface. While it is not uncommon to see homes with an accumulation of green stuff, it is important to take care of it in a timely fashion.

In this post, we cover what this green stuff is, how it got there, where it is typically found on a home, and how to remove it. We hope this provides proper insight for you to make educated decisions in removing the green stuff and keeping your home protected going forward.

I have green stuff on my siding. What now?

While the appearance of algae on your siding is not a good thing, there is no reason to panic. Following these steps will help you get rid of it quickly and effectively: Assess the problem areas and the severity of the algae staining. Hire a professional cleaner they typically will have an application of specialized cleansers used to eliminate the algae growth on your siding. After the cleansers have a moment to set, water is widely distributed on the siding to remove all algae safely and efficiently.

What happens if I leave the algae alone?

Truthfully, algae will not structurally harm the surface of your siding. It can, however, leave stains behind that embed themselves into the siding even after being washed. When these stains are embedded into the siding, they become a part of your siding rather than a stain. Embedded stains can be very difficult, if not impossible, to remove without structurally or aesthetically damaging your siding. The best way to prevent this from happening is to frequently maintain your home.

Where did the algae come from?

It is difficult to pinpoint the point of origin of airborne algae as it varies from region to region. One cause of algal blooms in Lake Erie, for example, is sewage and agricultural runoff washing into the lake and forming this buildup. While algae blooms happen naturally, this pollution allows the algae to feed and grow. Once that alga is airborne, it can attach to dirt on siding and surfaces to feed on.

Where is green stuff typically found on a home?

In most cases, algae is found on the north side of your home. One reason for this is that the north side of your home gets less sunlight than the other sides. Algae and mold form more easily in darker conditions and moisture. If untreated, additional dirt can make its way to your siding that algae can feed on, causing it to widen its coverage.

How do I keep algae off my siding for good?

The best way to keep your siding protected from algae growth is to get it washed on a yearly basis. Leaving algae on the home can cause the stains to embed themselves, and the algae will make its way back over time after an initial wash. By having the house washed annually, you will be able to keep your largest investment looking great and protected from algae growth.


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