Your siding is exposed to the elements, which leaves it susceptible to mold and mildew growth. Mold and mildew don’t just destroy your home’s curb appeal. They’ll eat through the siding and trap moisture against it to cause significant water damage. Here’s how house washing can prevent and treat these growths.

What Causes Mold on Siding?

Mold and mildew require three components to grow: an organic material to feed on, oxygen, and moisture. Many siding materials, such as vinyl or wood, serve as a source of food.

Sunlight kills most mold spores and mildew. This means that shady areas, such as those underneath a tree or on the side of the home that doesn’t get as much exposure, are more vulnerable. Sunlight won’t eliminate the spores nearby, which means once the wind blows the spores onto the siding, they can immediately start to grow.  

Mildew often feeds on dirt and dust as well. Siding material that’s covered in dirt or has tree sap on it is more likely to experience mold growth than a clean surface.

How to Prevent & Treat It

house washingRoutine house washing is the best protection against mold and mildew. Without the proper cleaning, dirt and other buildup will trap moisture against the siding and serve as excellent food for those unwanted growths. Hire a power-washing service to quickly remove all contaminants from the siding. This equipment should be handled by a professional, since using a power-washer incorrectly could cause water damage or chip away at your siding.

You should also keep your gutters and downspouts in clean, working condition to prevent any water from running down the siding. Trim back trees so that sunlight can reach the siding and sap won’t drip onto the house.


If you want clean siding, the professionals at Squeeky Clean Window Washing in Bethesda, MD, offer comprehensive house washing services. They also offer window washing for residential and commercial customers throughout Montgomery County, Northwest DC, and Northern Virginia. Their technicians utilize state-of-the-art equipment and industry-tested methods for reliable results. Learn more about their services on their website, or call (301) 424-4020 for a free estimate.