Rust Stains on Aluminum Siding

Moisture

• Rust is caused by moisture. While you can't control the weather, it is possible to limit some exposure to moisture. Make sure sprinklers don't hit the side of the house. Keep landscaping and planters at least a few feet away from the sides of the home so they don't trap moisture against the siding. Clean the siding on warm, dry days rather than cooler, humid ones so the water evaporates quickly and doesn't allow rust to take hold.

Weaknesses

• Aluminum siding is designed to resist rust. Under normal conditions and with proper maintenance, it should not. Damage and lack of care can allow rust to get a foothold, however, which can cause significant damage if not repaired quickly. Scratches in the paint and protective coatings expose the metal and allow it to rust. Oxidized paint will leave the aluminum vulnerable to rust. Regular maintenance to cover scratches and repainting as necessary will help prevent rust.

Repair

• Remove rust as soon as it appears on aluminum siding. If caught right away, it is easy to remove and won't cause serious damage. A stiff wire brush or sandpaper can be used to remove surface rust. Liquid rust remover may be needed to clean away more serious rust. After the rust is removed, protect the surface with paint so that the rust will not reappear.

Prevention

• Preventing rust on aluminum siding is the best plan. Inspect the siding regularly for damage and signs of rust. Pay special attention to seams, lower areas that could be damaged by children or pets, and areas near heavy traffic, such as by the garage. Clean the siding at least every six months to remove dirt. This will also make any rust underneath the dirt more apparent. Repaint the siding as soon as the existing paint starts to fade, oxidize or show any other signs of aging.