Chalking is the formation of fine powder on the surface of the paint film during weathering, which can cause color fading. Although some degree of chalking is normal, desirable way for a paint film to wear, excessive film erosion can result in heavy chalking.

Possible Cause:

• Use of a low-grade, highly pigmented paint.
• Use of an interior paint for an outdoor application.

Solution:

First, remove as much of the chalk residual as possible, use a stiff bristle brush (or wire brush on masonry) and then rinse thoroughly with a garden house; or use power washing equipment. Check for any remaining chalk by running a hand over the surface after it dries If noticeable chalk is still present, apply a quality oil-based or acrylic latex primer (or comparable sealer for masonry), then repaint with a quality exterior coating; if little or no chalk remains and the old paint is sound, no priming is necessary.