Mix one part bleach and three parts water in a bucket if mildew is present on the PVC. Apply the mixture to the PVC and allow it to sit for 20 minutes. Rinse it off thoroughly.
Clean the PVC with a mixture of detergent and water. Use a soft-bristled brush to scrub it free of any dirt or mildew. Rinse and allow the PVC to dry.
Lightly sand shiny parts of the PVC with 220-grit sandpaper to create a better bonding surface for the paint. Use a damp cloth to wipe off the dust.
Prime the PVC with one coat of acrylic primer. For large surfaces, use a paint roller; for smaller surfaces, a standard paintbrush is fine. Apply with even brush strokes.
Apply the finishing coat. Paint the PVC in the same fashion as the primer coat using exterior acrylic latex paint.