Fences built using pressure-treated wood require a different type of paint than untreated wood. While treated wood receives protection against termites and decay, a treatment of water sealer helps keep moisture from getting into the wood. The sealer also keeps the wood from splitting or cracking. Recently constructed fences require a waiting period of up to two months before any kind of finish gets painted on the wood. However, if the wood was kiln-dried after treatment, you can start painting immediately.
Apply a coat of water-repellent/sealer preservative to your newly-installed fence. Make sure you use a liberal dose on exposed board ends and on all joints. Wait several days for the preservative to thoroughly dry. The preservative gets absorbed into the wood and will not offer any kind of shine or colour. If you need to repaint your fence, complete the next step first, then apply the sealer.
Spray your fence with water to remove any dirt or debris, if the fence was installed months or years ago. Scrape any loose paint or dirt from an older fence using the scraper and bristle brush. Use sandpaper to smooth any rough surfaces.
Wait for the fence to dry over a period of several sunny days.
Grab a can of stain-blocking acrylic latex primer and brush a coat on the fence. The primer coat helps prepare the fence for the exterior paint you're about to add.
Brush two topcoats of acrylic latex exterior house paint on your fence once the primer dries. Now you are ready to enjoy your beautiful fence. Plan on repeating the process every 1 to 2 years to keep the fence looking attractive and well-kept.
Choose a sealer/preservative that contains mildewcide. This helps keep mildew and mould from causing rapid wood decay. Make sure your fence is completely dry before applying the sealer/preservative.
Avoid use of varnish finishes or solid-colour stains since they cannot take much sun and rain, and will require lots of refinishing. Use gloves when handling the wood and while sanding, scraping or applying the sealer, primer and exterior paint.