What Causes Vinyl Siding Discoloration?

Chemicals

• While vinyl is a durable siding choice, it is made of organic materials that make it vulnerable to damage from certain chemicals. Stains, herbicides, insecticides and deck sealants used around the exterior of your home may stain your vinyl siding or cause discoloration. When treating your garden or re-painting your deck, take care that these chemicals aren't splashed up onto your siding. Cleaners that contain organic solvents, undiluted bleach, grease, nail polish removers, furniture polishes and cleaners will also cause discoloration on vinyl siding. With any chemical, check the label to ensure it is formulated for use with vinyl siding before using.

Sunlight

• Vinyl siding is manufactured to resist fading, but over time discoloration from UV rays is unavoidable. The areas of your home that are subject to the most intense or direct rays typically show noticeable fading more rapidly than the vinyl on shaded sections. This discoloration typically takes several years on properly maintained vinyl siding. One option is to side your home with lighter color of vinyl. Dark colors absorb more heat, and fading is often more noticeable.

Mold and Mildew

• Mold and mildew will develop on vinyl siding that isn't cleaned regularly or that has been exposed to chemicals that have deteriorated the surface. Because it is made of organic materials, vinyl provides an ideal environment for their growth. If left long enough, mildew can permanently discolor vinyl siding. If your siding appears dull or has grey patches, cleaning it with mild detergent and water may bring back the original color.

Dirt

• Although manufacturer's guidelines recommend washing your siding once every few years, you may need to clean it more frequently to prevent discoloration. If your home is in an area where dust is abundant, the siding will begin to look dingy as dirt and dust cling to the vinyl. Cleaning your siding every year or twice each year in regions that are dry and dusty can keep your siding looking newer longer. When cleaning, check the manufacturer's recommendations regarding pressure washers and don't spray with pressure above 500 psi. Too much pressure will penetrate the surface of the vinyl and contribute to the siding's deterioration.