Warped Door
Photo: Courtesy of Trustyle
An interior door made of medium-density fiberboard (MDF) won't warp, but it should be painted on all sides to protect the material from moisture.
Q: The bottom corner of the 1 3/8-inch-thick, 6-panel pine door leading to our garage has warped inward about ½ inch. The problem starts at the door knob and gradually increases toward the bottom of the door. Is there any way to correct this, or should I just replace the door?

—John Pistone, Granite City, ILL.

A: Norm Abram replies: I have a similar, if not quite as dramatic, problem in my house on passage doors, cabinet doors, and doors on furniture. Wood is not the most stable material—especially solid pine—and it's particularly susceptible to changes in humidity. Over the years I've tried a few things to correct this problem, but nothing seems to work permanently. The wood always wins and goes where it wants to.

My guess is that the bottom edge of your door is not sealed with paint or polyurethane, and that ­allows moisture to migrate up through the end grain and warp the wood. If you discover that this is true, take the door off and apply a finish so that the problem doesn't get any worse.

Still, the warp may never go away completely. If it were my house and the door wasn't letting in a draft, I wouldn't do anything. But if it bugs you, think about getting a new door made of MDF—medium-density fiberboard. It will need to be painted on both sides and every edge, but as long as it doesn't get wet, this engineered material is more stable than solid wood.
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