Treating Cedar Wood
Q: I have a one-year-old cedar fence that gets a lot of sun. It has not been stained. What is the best treatment to preserve the wood? Color is not as important as longevity. - Keith
A: The treatments which can last the longest and give the best protection to outdoor wood, such as fences and decks, are paint and solid color stains (which are much like paint.) They protect wood well because they are good at screening out the sun's damaging ultraviolet rays and sealing out moisture. Unfortunately, these treatments are sometimes a poor choice because they can peel and flake if the surface is not properly prepared or poor quality products are used. They also conceal the grain and natural color of the wood.
Cedar and redwood contain oils that can bleed through latex paint, so a stain-blocking primer should be applied first, or an oil-based paint used. High-quality paints and solid color stains, properly applied, generally last up to 10 years on outdoor wood.
Other finishing choices fall well short of paint and solid color stains for protection and longevity. Clear water-repellent preservatives are seldom effective for more than two years. Lightly pigmented stains (sometimes called semi-transparent stains) are better at screening out ultraviolet light and can last for up to about five years.
If this was my fence, I would not give it any finish at all. In fact, that's how I handled a cedar fence I installed more than 20 years ago, and I am still happy with the fence. Cedar and redwood are naturally durable woods that can survive sun and rain for many years. Like other outdoor woods, they will gradually turn gray if left unfinished, but the color is not necessarily displeasing. The natural color can be restored by spraying the wood every few years with a bleach-type deck cleaner.