Use soap and water to hand scrub the old siding and make sure to thoroughly rinse it clean. Do not power wash vinyl siding as water can get behind the vinyl siding. If mildewed surfaces, use oxygen bleach cleaner. Paint in the shade or when overcast, never in direct sunlight.
Thermal Expansion of the Vinyl
Understand that vinyl siding was designed to be installed so that it slides back and forth just slightly at its overlapping seams as the siding expands and contracts. When that happens and the siding contracts in cold weather, you may have a slight color gap at the seams.
Paint Color Limitations
The vinyl siding plastic composition at factory was designed for a specific amount of heat absorption. As a result, do not pick a color shade darker than the original or you may have warping or buckling due to the darker color absorbing more heat than the original vinyl siding was designed to handle.
Type of Paint to Use When Painting Vinyl Siding
Buy a paint with blend of urethane and acrylic resins. Water based urethane mixed with quality acrylic resins provide excellent adhesion, so buy only a quality exterior latex urethane paint such as Sherwin Williams Duration or Sears Weatherbeater ULTRA (which is also made by Sherwin Williams).
