Problems
You see: A black line opening up on the bottom of an exterior wood door. Cause: This often occurs on an exterior French-style door where two portions of wood meet near the bottom. Wind and rain can drive moisture under and into the door if it's not properly sealed and installed. The paint should be even on the door, with no spacing anywhere between the pieces. If you see a space opening up, the door is on the road to failure, Dawson says. “Moisture goes in there, and it’s a domino effect,” he says. “Once moisture starts expanding and contracting, it breaks the joint, and the process starts. Wood doors and wood windows are hell. They require a lot of maintenance.”
You see: Black streaks or black circles around nails on hardwood floors. Cause: This most often occurs near doors. If you’ve got an old home with exposed nail flooring and you see blackness around those nails, chances are that you’ve got moisture getting underneath the door sill, and it's corroding the nails. If the wood is cupping up, the problem is really bad. Who to call: A home repair specialist to do the preliminary fix, then you’ll need a flooring specialist to refinish the area.
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