You might typically associate mould growth with damp, dark interior spaces, but your home's exterior siding can be susceptible to mould growth, as well. Excessive moisture and humidity can create an attractive environment for mould growth on several kinds of siding, including low-maintenance vinyl. Learn more about what causes mould on vinyl siding and other materials, and discover how you can reduce the risk of a dangerous or costly mould outbreak on your home's exterior.

Causes of Mould on Siding

Siding is designed to allow rainwater and other types of moisture to run off the exterior walls of your home, but even otherwise durable siding can be susceptible to unsightly mould growth under certain conditions. Excessive rains or continual contact with water (such as from a lawn sprinkler) can increase the moisture content on and under your siding, thereby elevating your risk of mould. Since some mould types may need humidity to grow, warm and humid weather conditions can also help make circumstances ripe for a mould outbreak on your siding.

Light can also play a role. Mould likes darkness, putting shadier areas of your house particularly at risk. These areas will also tend to be the slowest to dry out, which means moisture levels can remain dangerously high. If you have trees or shrubs that shade part of your home, check those areas first for mould. Additionally, the side or sides of your house that don't receive direct sunlight may also be at higher risk of a mould outbreak.

Vinyl Siding Mould Removal and Prevention

Now that you know the conditions that encourage mould growth, you're ready to reduce your mould risk. First, keep your siding clean of dirt and grime, as clean siding dries faster and repels water better. Your garden hose or a pressure washer are usually adequate tools for cleaning different types of siding, including vinyl siding. For tough spots, a scrub brush and cleaning solution may be useful. According to the Vinyl Siding Institute, a simple vinegar and water solution is effective in cleaning mould from vinyl siding.

Tip: Don't spray your hose or pressure washer upward at the siding, as you can get water underneath the panels. Always spray straight ahead or downward.

Next, target the vegetation around your house that creates those shady spots that mould loves. Keep trees and shrubs away from your siding, as contact can transfer water from vegetation to your exterior walls. Regularly trim your trees and shrubs to minimize shaded areas that can encourage mould growth.

Finally, take steps to reduce the amount of moisture that hits your siding. Adjust lawn sprinklers as necessary to keep them directed away from your home. Additionally, ensure that your gutters are clean and in good working order. Clogged or leaking gutters can cause rainwater to run down your exterior walls and can increase moisture levels on and under your siding.

Mould's Effect on Your Home

Mould on your siding may indicate mould growth in other areas of your home. When moisture becomes trapped under your siding, it can seep through to interior walls, especially if your home lacks a weather barrier. Since mould can spread quickly, cleaning mould from vinyl siding is essential as soon as you notice it beginning to appear on your home's exterior.

Preventing mould on your siding begins by monitoring and reducing the conditions that encourage mould growth in the first place. Keep a watchful eye on your home's siding for any signs of mould, and be prepared to take action to prevent a major outbreak. For serious mould problems, don't hesitate to call in the professionals at ServiceMaster Restore.