How Often Does Clapboard Siding Need to Be Painted?

Preparation

• Clapboards -- or lap siding, as its called in the South -- require impeccable preparation for a lasting paint job. Preparation IS painting, as professional painters say. Old boards must be stripped of loose paint and sanded so new paint will adhere. Rotten and spongy boards must be replaced and old nail holes, major dings and gouges filled with exterior wood filler.

Priming

• Exterior oil primer improves paint adhesion and seals rust-prone nail heads and filler. Exposed wood and new boards can be coated with wood preservative first to improve primer and paint adhesion. A well-kept pro painter's secret, wood preservative reduces water absorption of wood fibers, therefore reducing swelling and shrinkage, which helps keep paint from peeling. Look for a product the claims to be water repellent, preservative and paintable.

Top Coat

• Exterior latex paint is the best choice for house paint these days. It is durable and flexible, moving with the wood as it moves with the weather. Buy the best paint that you can afford for a long-lasting coating. Look for latex paint that has a high percentage of acrylic binders. Two coats give a thick enough coating to cover the primer adequately.

House Maintenance

• Extend the life your paint job by diverting water away from the house. Make sure gutters are clean and sloped in the right direction to keep them running freely. Downspouts and splash guards keep rushing water from splashing onto and under the siding near the foundation. Maintain proper flashing around windows, doors and chimneys to drain water away from the clapboards.

Paint Lifespan

• When paint is slapped on clapboards without preparation and priming, you can expect paint failure in just a few years. But if you use good preparation methods and excellent-quality paint and vigilantly maintaining your house, you can expect many years of service. On well-cared-for exteriors, the paint on the dry, sunny side of a house might last as long as 20 years. Paint under a tree on the north side might only last 10. Yearly inspections, followed by clapboard repair and touch-ups, will extend the life of a paint job and reduce the preparation necessary for the next all-over painting.