Repairing Wood Siding and Shingles
Damaged siding permits moisture to enter exterior walls, where it can rot the sheathing and even the framing. It needs quick attention. Keep exterior walls well covered with quality paint . Make repairs as soon as you spot damage. Pack small cracks, splits, and open seams with latex/silicone or butyl caulk. You may be able to repair splits and holes using epoxy wood filler. If not, you’ll have to replace the damaged board or shingle. If more than a few boards or shingles are failing, consider re-siding the entire wall.
Tools: Chisel, hammer, pry bar, close-work hacksaw, square, putty knife, utility knife, plane, backsaw, drill, caulking gun.
1. Loosen the board. To remove a length of siding, cut through the paint along its bottom edge. Work a chisel under its lower edge, then switch to a flat pry bar. To keep from damaging the surrounding siding, pry by pulling away from the house rather than pushing toward it.
2. Pry it away. Each course of lapped siding is held in place by nails driven through the course above it. First deal with the lower nails. If the nails begin to come out with the board, jam the nail with a pry bar and tap the board down. This may cause the heads to pop out, making them easy to pry away. The same can be done for the nails in the course above.
3. Cut nails that won't pop out. If the nails aren’t cooperating, or if they are not accessible from the surface, slip a hacksaw blade underneath the siding and cut them. A close-work hacksaw works well for this. Be careful not to scrape the siding beneath the damage.
4. Prepare to cut out the damaged area. To cut a piece to length, tap wedges under the course above and use a square to mark the cut lines. Cut first with a utility knife to diminish splintering.
5. Saw the siding. Use a backsaw or fine-toothed handsaw to cut the face of the siding. Use short strokes, holding the top of the blade to keep it from buckling. As you finish each cut, be careful not to cut siding below the damaged area.
6. Split away the damage. Split the damaged area along the grain and remove a piece at a time. Carefully pry away all remnants under the board above. Pry away or pound down all nails. Check that the replacement piece can slide all the way up into position.
7. Seal the building wrap. If you puncture the building paper underneath, seal it with roofing cement. Or cut a piece of roofing felt (tar paper) slightly larger than the opening and shoehorn it in. Fasten any loose paper with roofing nails or staples.
8. Slip in the patch. Cut the replacement for a snug fit, then slide it under the board above, tap it into place, and remove the wedges. Avoid too tight a fit, however. Use a block plane to skim off one edge if you have to force the patch.
9. Drill pilot holes. Wherever you will drive a nail less than 3 inches from the end or edge of a board, drill a pilot hole first to prevent splitting the board.
10. Nail, and caulk the seams. Finally nail the new board at the top and bottom. Use siding nails, which have thin shanks. Fill nail holes and the vertical seams with caulk, then prime and paint.