Fix Now, Save (A Lot) Later

Potential problem: Damaged wood can allow rainwater to make its way into the wall, leading to decay and insect damage. Rot may also spread to surrounding boards.

Fix it now: Replace the board for $100 or less, depending on the wood type. "Don't just caulk the crack," says Norm. "That'll get loose and invite more water to get behind the siding." For a tight fit on the first try, mark the old board's length directly on the new one. Score the cutline using a utility knife, and slice off the overage with a handsaw.

What you'll save: Up to $3,000 to re-side and rebuild a rotted wall, including new clapboards, sheathing, framing, and drywall inside, plus $2,000 or so for termite or carpenter ant control.

DIY: Learn how to remove a broken clapboard and install a new one without damaging the surrounding siding.