The formation of fine powder on the surface of the paint film during weathering can cause the paint colour to fade. Although some degree of chalking is a normal, desirable, way for a paint film to wear, the paint film can become excessively eroded through heavy chalking.
- Using a low-grade, highly pigmented paint.
- Using an interior paint for an outdoor application.
Remove as much of the chalk residue as possible by scrubbing the surface with a stiff bristle brush (or a wire brush for masonry), and rinse the area thoroughly. Alternatively, use power-washing equipment to clean the surface.
Check for any remaining chalk by running a hand over the surface after it has dried. If a noticeable amount of chalk is still present, apply a quality solvent-based or acrylic water-based primer (or comparable sealer for masonry), then repaint the surface with a quality exterior coating. If little or no chalk remains and the old paint is sound, no priming is necessary.