Paint that has lost its adhesion can generally be traced to moisture in the material, which causes the paint film to loosen, crack, and ultimately peel off.

Causes:

• Moisture seeping to the surface through worn or uncaulked joints or through leaks in the roof or walls.

• More water vapor than the paint can transmit is escaping through the exterior walls.

• A solvent-based paint was applied over a damp surface.

• Blistering has occurred and gone uncorrected.

What to do:

• Locate and eliminate the source of the moisture. If the condition is localized, remove all loose paint and sand smooth. Then spot prime with exterior latex primer and top with a coating compatible with the existing paint.

• Otherwise, completely remove all old paint. Once down to the bare wood, prep with exterior latex primer and repaint with exterior latex.