The Problem: A common exterior paint issue resulting in the development of a fine powder on a surface coating due to weathering. All paints have a tendency to chalk over time. High quality paints may chalk mildly, but maintain a sound surface for several years. Medium and heavy chalking is characteristic of lower quality paints and can cause color fading, as well as make it difficult for any new top coatings to adhere.
Causes: Include the use of low quality paint, long term exposure to moisture and sunlight, and not properly priming and sealing a porous surface.
How-to-fix: Depending on the surface, excessive chalking requires pressure washing or sand blasting to remediate the problem. Light to moderate chalking will require wire brushing or sanding, followed by rinsing with a garden hose to remove excess surface powder. Allow the surface to dry thoroughly. If little or no chalk remains and the old paint is in good condition, no priming is necessary. In all cases, recoat with a high quality exterior paint.