By Gene and
Over the years the effects of wind, rain, sun and snow can damage a wooden fence and the metal fasteners and hardware used in its construction. The dimensional stability of wood changes with excessive moisture so it's one of wood's worst enemies. Water can also lead to decay or rot. A wooden fence is susceptible to damage from insects and fungal attack, too, not to mention decay organisms that can grow in moist wood. You can protect it from these elements and extend its life with a water-repellent sealer.
Wood posts and planks are vulnerable to rot at the ends because end grain absorbs water more easily than the rest of the plank. For that reason the ends should be well sealed. This is especially important for the top of the fence posts. A post top should be cut at an angle to promote drainage or protected with a post cap to prevent water from pooling. Inspect the top of all posts for signs of splitting or decay. If the post is cut square, re-cut it at a slight angle, if possible. In any case, thoroughly coat all the end grain of the posts and fence planking with a water-repellent sealer.
Beat the Mildew
A build up of dirt and mildew on fence posts and planking is an invitation to rot. The least expensive and easiest step to extend the life of a fence it to keep it clean. Wash away dirt and mildew especially on the north or shady side of the fence. Use a mixture of one cup of household bleach to a gallon of water. Commercial house wash solutions are also effective for this process.
Power washing will effectively clean even the dirtiest of fences. Consider hiring a deck cleaning/house washing service to power wash the house, deck and fence. You can save some money by having all the cleaning done at one time. Another option is to rent a power washer (available by the hour or day) and do it yourself.
After cleaning, a natural unpainted fence should be given a coating of a water-repellent sealer. Products with a UV inhibitor are a good choice since UV radiation from the sun is a major cause of wood deterioration. Treat the fence, posts and rails and give special attention to the post area close to the ground. Apply the finish with a paintbrush, roller or sprayer according to the manufacturer's directions.
Before Painting a Fence
Apply a water-repellent sealer to unfinished wood before painting it to increase the protection and life of the paint. Check the recommendations of both the paint and sealer manufacturers for product compatibility.
Loose and flaking paint is a sign of paint failure. A power washer is very effective removing loose paint while it cleans off dirt and mildew. To repaint it, first scrape off the damaged paint and coat all bare spots with a sealer. When dry, use an exterior primer followed by a protective topcoat of exterior house paint.
Gate hinges and latches are especially vulnerable to weather damage because over time the screws can loosen as wood expands and contracts. As they loosen, the screw holes enlarge so water can penetrate the wood and promote rot. Every year, inspect all hardware. Then tighten or replace any loose screws. Be sure to use galvanized or at least zinc coated screws and hardware on the fence.
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