How should exterior wood surfaces be prepared before painting?

• A. Remove loose paint, clean, dry rot, sand, and apply primer.
• B. Treat rot, then paint directly.
• C. Dry the wood, then apply topcoat.
• D. Remove loose paint, clean, treat rot, dry thoroughly, sand, and apply a suitable primer.

Answer: (D)

Preparing exterior wood surfaces starts with making the surface solid, clean, dry, and ready to bond with paint. Begin by removing all loose and peeling paint so the new coating can grip a sound edge rather than flake off. Clean the wood to remove dirt, oils, and mildew, since contaminants interfere with adhesion. If there is rot, treat or repair it so the wood isn’t decaying under the finish; unaddressed rot will continue to weaken the surface and cause failure of the paint job. Dry the surface thoroughly because painting over damp wood traps moisture, leading to peeling and mold growth. Lightly sanding creates a rough, even surface and feathered edges so the primer can adhere smoothly. Finally, apply a suitable exterior primer that is compatible with the topcoat; the primer seals the wood, improves adhesion, and provides a uniform base for lasting coverage. Skipping any of these steps—or applying primer and paint too soon—risks poor adhesion, premature peeling, and reduced durability.