What Are the Causes of Mold on the Outside of House Siding?

eHow may earn compensation through affiliate links in this story. Learn more about our affiliate and product review process here.

House sidings protect the structural integrity of the home and provide an aesthetic finish. Siding comes in natural and man-made materials, which vary in cost and durability. Professional installers and manufacturers suggest periodic inspection to prolong the life of siding. The most common problem is mold.


Siding Benefits

Video of the Day

Most kinds of siding eliminate the need for painting, require little maintenance, increase insulation and reduce noise penetration. Some are crack resistant and even fire resistant. None are totally mold resistant, including siding treated with anti-fungal substances.

Video of the Day

Kinds of Siding

Wood clapboard is made from wood boards and installed with nails in an overlap pattern that allows the wood to expand and contract. Other wood styles are shingles, shakes and logs. Since it is a natural material, wood is susceptible to mold buildup. Metals such as aluminum and steel can rust from excessive moisture. Stucco is a cement mixture that includes water, which attracts mold. Stone is known by a number of names, including rock siding, stone veneer and stone facade. It, too, can attract mold, just as stone does in the woods. Vinyl is the easiest surface to clean and maintain, but it too can become moldy.


Water Problems

Mold will thrive if the ground next to the house is constantly wet. Correct problems such as poor rainwater runoff, poor drainage, dripping gutters and leaky outdoor faucets and hoses.


Excessive Shade

While shade keeps your house cooler, it blocks the sun from drying off your siding. That makes it susceptible to mold, particularly in damp climates. Soffits, which are not exposed to direct sunlight, attract mold as well.


Inadequate Air Circulation

Besides the sun, air circulation can dry off siding. But if you have dense bushes next to your home, rain-slicked siding will not dry out. Mold likes dark and damp places.

Vines on the House

Various kinds of ivy and other vines may enhance the look of your house, but they can be bad for the siding. Vines latch onto surface, sometimes causing cracks that allow moisture to penetrate the siding. Besides fostering mold, the cracks provide entryways for insects.


Maintenance Tips

Keep gutters and downspouts clean. Fix leaking faucets and hoses. Landscape the perimeter around the home to push water runoff away from the structure. Keep vegetation away from the house to allow for sunlight and air circulation to dry the siding. Inspect the outside surface several times a year. Wash away dirt . Immediately remove mold with bleach and water, natural anti-fungal soaps and sprays or treatments recommended by the manufacturer of your siding.



Report an Issue

screenshot of the current page

Screenshot loading...