This article was crafted with the help of Preferred Siding, Inc.

Mold on siding is not only unsightly, but it can also cause health problems and damage to your home. So what causes this gross fungus in the first place? According to Steve Ginsberg of Preferred Siding in Northern Virginia, the mold is organic matter combined with moisture.

“When you have things like dust and pollen remaining moist on siding, and no sun or airflow to move it along, mold can begin to grow.” This explains why homeowners so often find mold on the shady sides of their home.

No Siding Is Safe

“Brick, wood siding, vinyl siding, and cement siding—none of them are impervious to mold,” Steve explains. “Even siding that is processed with fungicide can still grow mold.” What’s a homeowner to do?

Steve recommends regularly hosing down your siding to keep organic matter from resting on it. (However, do not confuse hosing down your siding with power washing, which can sometimes cause more harm than good by damaging siding and voiding warranties.) 

The frequency with which you should hose down your house depends on a variety of things. If certain parts of the siding are in very shady, dark areas, those spots should be hosed off once every month or so, but if your siding is in bright, open areas and has never had a tough mold problem, twice a year should be all you need.

Steps to Eradicate Mold

If you already have mold, the process is a little different depending on the type of siding you have. Before treating your siding, Steve advises checking with the manufacturer. “As with all home improvement, it’s not what you expect; it’s what you inspect. You are responsible for doing your own research. 

When it comes to siding care, certain things can void the manufacturers’ warranties, so it is safer to call the manufacturer of your siding products and ask them what they recommend for mold and mildew. It would even be helpful to send them photos of your problem, so they can see what you’re dealing with.&rdquo This is a good rule of thumb to follow before completing any work on your house.

Steve cautions homeowners to “pay attention to the details and find out the proper way to do things” to avoid significant issues. In addition to calling the manufacturer directly, homeowners can also contact an association that specializes in the type of siding they have, such as the Vinyl Siding Institute or the Western Red Cedar Lumber Association.

The next step in eradicating mold on siding is typically cleaning the siding with a bleach solution, which is either sprayed or brushed onto the affected areas. This can be done by either the homeowner or a professional contractor. Homeowners can then try applying a mildew blocker to keep the matter from returning.

Paint with special additives to reduce mold and mildew can also be helpful. But buyer beware—Steve warns that these products do not guarantee mold-free siding forever. “Once mold or mildew has made its home on the siding, it can be hard to get rid of, particularly on wood siding.”

Prevention Is Key

Aside from hosing down your home, there are other ways to help prevent mold and mildew from forming on your siding.

  • Tree limbs should not be pressed right up against the house, as this can cause stagnant air and deposit organic matter directly onto your siding.
  • Prune all plants and bushes away from your siding, so there is ample air circulation in between them and the surface of the home.
  • Avoid aiming your sprinkler system directly at your house, because moisture can increase your chance of mold and mildew growth.
  • When installing siding, ask your installation company what they would recommend for preventing mold growth. Prevention is better than treatment.

Seeing mold on any part of your house, inside or out, is an unfavorable situation because of the added problems it can signify. With the right prevention and treatment, homeowners can keep their house clean and attractive.

This article was crafted with the help of Preferred Siding, Inc., a Northern Virginia expert in Siding. While we strive to provide relevant information to all homeowners, some of the material we publish may not pertain to every area. Please contact your local Best Pick companies for any further area-specific advice.

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