Be prepared for regular maintenance no matter what finish you choose
by Scott Gibson

Despite the growing use of wood-plastic composites and all-plastic or metal decking, most new residential decks are still made from wood. And while pressure-treated lumber and naturally decay-resistant species such as cedar and redwood can last a very long time outside, they aren't immune from the effects of weather. Thus, most homeowners and deck professionals will turn to a deck finish to slow the aging process and prolong the life of their decking.
The available finishes run the gamut from semisolids that hide wood grain to clear preservatives designed to keep wood looking lumberyard fresh and the options continue to multiply. In addition to traditional finishes made from natural oils, there are finishes made from modified oils called "alkyds"; water-based acrylics; and coatings that combine acrylics and alkyds.
No finish does everything perfectly, especially in a grueling environment where heavy foot traffic, unrelenting sun, and exposure to rain and snow are the norm. Also, there's no such thing as a permanent, maintenance-free finish all will need periodic cleaning and recoating.
That said, there are fundamental differences between families of finishes that affect performance, appearance, longevity, and (of course) price. And just as your painter will tell you, surface preparation is everything.
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