Introduction Damaged siding lets moisture enter exterior walls and rot away their framing. Make repairs as soon as you spot damage. Pack small cracks, splits, and open seams at board ends with latex or butyl caulk. If more than a few boards or shingles are failing, however, consider re-siding the entire wall. You may be able to repair badly split pieces by applying waterproof glue directly into the split. If not, you'll have to replace the damaged board or shingle -- an operation that requires careful, but not skilled, carpentry. The problem is that each course of lapped siding is held in place by nails driven through the course above it. The drawings below show how to repair lapped wood siding. Use the same steps to replace wood shingles, but don't try to pry out the nails; cut them underneath the shingle with a hacksaw.

Wood siding is very durable but can be damaged by excess moisture.

1. Remove damaged siding To remove an entire length of siding, work a chisel under its lower edge, then switch to a pry bar.
2. Expose nails If the nails begin to come out with the board, jam the nail with a pry bar and tap the board down.
3. Cut inaccessible nails If the nails aren't accessible from the surface, slip a hacksaw blade underneath the siding and cut them.
4. Removing small sections If the damage is limited to a small area, tap wedges under the course above and use a square to mark the saw cuts. Cut along marks.
5. Removing in pieces Split damaged area along the grain and remove a piece at a time. Remove all remnants under the board above.
6. Seal punctures If you puncture the building paper underneath, seal it with a liberal coat of roofing cement.
7. Cut and place replacement Cut the replacement for a tight fit, then slide it under the board above, tap into place, and remove the wedges.

BHG