How to remove mildew from your home’s exterior

People who live in regions with high humidity may find their homes are vulnerable to exterior mildew growth. Mold thrives on any organic matter and surfaces with moisture management problems. Mildew, in particular, lives on shower walls, windowsills and other places where moisture levels are high. Mildew also can grow on home siding as well as fences and other exterior structures. While typically gray or white, mildew can be various colors.

Experts recommend various cleansers to help combat the issue of mildew on a home. One of the first products that homeowners tend to reach for is sodium hypochlorite, which is a standard bleach used in laundry and pool sanitation. While sodium hypochlorite seems to make mildew vanish, those at This Old House say that chlorine evaporates too quickly to get to mildew’s roots on porous surfaces, such as wood or vinyl siding. Bleach also can stain clothing and damage foliage around the house. Hydrogen peroxide, or oxygen bleach, is less volatile, will not affect foliage and can clean mildew, algae and dirt on and below the surface.

Trisodium phosphate is another effective cleanser. Commonly known as TSP, it often succeeds where other solutions fail in regard to stubborn stains and mildew. TSP also works well on various exterior surfaces. TSP needs to be used with extreme caution. When using TSP, wear long sleeves, gloves, goggles, and a respiratory mask, says Today’s Homeowner. The product also requires adequate ventilation. There also are some environmental concerns, as TSP can damage foliage. In addition, if the product ends up in lakes and streams, it can trigger an overgrowth of algae that results in the depletion of oxygen levels in the water. Eco-conscious homeowners may want to try oxy cleansers before TSP.

Mildew shies away from bright sunlight, so it tends to grow on the north side of homes. Removing trees or other foliage that can further block sunlight to areas of the house can help eradicate mildew growth and stop it before it starts. Another tactic is to clean out gutters regularly and thoroughly to reduce moisture and to prevent decomposing debris from running over the edge of the gutters. This runoff can drip down the home’s siding and spread the mildew to other areas.

Mildew can be problematic any time of year. Clean up mildew when the weather cools down to spruce up the look of a home.