• Manifestations
  1. Washing down of chalk from an excessively eroding painted surface can ruin the surface of the lower area.
  2. For example, chalk run-down from an exterior wall can ruin the appearance of a brick foundation.
• Causes
  1. Using low-quality paint that is highly pigmented.
  2. Painting an exterior surface with an interior paint.
  3. When factory-finished metal siding erodes.
• Solutions
  1. Removing as much chalk residue as possible. Using a detergent solution and a stiff brush to scrub stained areas. Rinse thoroughly.
  2. In cases where the stains are severe, it may require using an acid wash. If the area treated is a different color after drying, paint with a quality latex paint.
  3. Aluminum siding that has eroded should be cleaned using the power washing method. Then apply a quality exterior latex paint.