Painting windowsills and wood door frames with hydrophobic paint protects the surface from ultraviolet rays and moisture. Water-based paints are more environmentally friendly than oil paints. Choosing a paint that is resistant to microorganisms prevents mold and mildew growth.
If wood surfaces are badly weathered, sanding, power rinsing and drying should be done before applying paint. Primer should be applied after the wood dries, and painting should follow when the primer is dry. Moisture meters detect moisture contained in wood. The moisture content in wood should be around 12 percent in most parts of the United States and 9 percent in the southwestern areas of the country. Painting wood surfaces with a moisture reading of more than 20 percent leads to peeling and cracking.
When painting exterior vinyl siding, choose paints that are marketed as vinyl safe. Experts recommend using paints that contain acrylic resins and urethane for maximum adhesion and durability. Darker paints absorb more heat into the plastic and warp the siding over time, but certain dark-colored paints are vinyl-friendly. The sidings can be washed with soap and water before painting, but power-washing should be avoided to prevent water seepage behind the sidings.
With outdoor decks and porches, sanding wood surfaces should be done to open the pores in the wood. This allows the wood finish to penetrate into the wood much deeper, and also gets rid of damaged fibers and stains. When sanding, wear a protective mask and goggles for protection against wood dust.