Q: I have a 6-foot-high fence that is about two years old. It was built with CCA-treated lumber, including 6x6 posts, 2x4 cross members, and 1x4 fencing boards. My problem is with the posts. They're about 8 feet on center, and all of them have started to twist. The ones that get the most sun are twisting the worst. The problem is getting so severe that I'm afraid the cross members will disconnect from the posts. Any ideas on how to twist these posts back?

— Lee , Morrisville, N.C.

A: Norm Abram replies: I'm afraid you're out of luck here. Once wood twists, it won't twist back. Wood often twists as it dries, particularly if it's a lower grade or if the sun hits one side more than the others. Posts are particularly prone to this problem because one end is always free to do what it wants. Pressure-treated posts are even more likely to behave this way because they're saturated with water and chemicals during the treatment process and often haven't dried out enough before they're put in the ground. Sounds like that's the stuff you ended up with. Maybe you can live with a slightly off-kilter fence — at some point, your posts will stop twisting — but if you do decide to dig them up and put in new ones, you'll want to use better-quality material. The best pressure-treated lumber is graded Number 1 or better, has factory-impregnated water repellent, and is kiln-dried after treatment (KDAT). Look for the KDAT initials on a tag or stamp; they mean the wood's moisture content is about 19 percent. But even the best pressure-treated lumber can twist, too, although usually not as much as what you're seeing. The most stable (and expensive) wooden fence posts are milled from cedar or redwood. Before you plant them, soak the ends in wood preservative for extra durability.
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