Home Tips : How to Repair Wood Siding

How to repair and prevent wood siding problems, including holes, warps, leaks between boards, and more.

Wood siding comes in many forms, including several types of boards, shingles, and sheets. If you have woodworking skills, you can tackle small repairs by duplicating the way the siding is installed. Special tools such as shingle-nail pullers may be needed for certain jobs.

Large repairs generally require more equipment and more hands, and the work becomes more difficult the higher up the wall you go. If the work extends beyond replacing a board or a shingle or two, you may want to hire a professional. Contact a local siding contractor who can handle repairs on all types of wood and hardboard siding.

As you repair damage, identify what caused the damage, and correct the problem promptly. For example, if your wood siding was damaged by leaky gutters or poor drainage from the downspouts, correct those problems before more damage develops.

If paint problems are confined to a small area, you can touch them up. If they are more extensive, you may need to repaint the entire wall or house. Before painting, solve the cause of the problem.

Keep an eye out for dry rot and termite damage. Both are found on exterior as well as interior wood and can cause serious structural damage to your house. Dry rot is crumbling wood caused by a fungus. Termites bore tunnels through wood; you’ll sometimes see their wings or the castings they push out. Call pest control professionals if you find termite damage.

Before painting, make sure surfaces are clean, dry, and in good shape. It’s best to paint in dry weather with temperatures between 50 and 90 degrees F.

For repairs that will match natural-wood siding, you’ll want to use stainable wood putty. If you intend to paint the patched area to match the siding, use pre-mixed bridging and patching compound, sold at paint stores and home improvement centers. Follow the label directions; most advise you to:

1) Remove any loose material from the hole, and brush the hole clean.

2) Apply the filler with a putty knife. Small holes require only one application; build up the patch with several layers (allowing each to dry in between) for large holes.

3) Sand the surface, and finish it to match the rest of the siding.

If board siding is butted together too tightly during installation, it may warp when it tries to expand with moisture changes. You can try pulling the board in flat and tight by driving a couple of long, galvanized screws through the siding into studs (drill pilot holes to avoid splitting the siding). But chances are good that you’ll need to slightly shorten the warped board. Here’s how:

1) If the boards seem to be jammed together at the ends, pry out the nails from the warped area, and continue pulling nails (or you can cut them with a hacksaw blade), working your way toward the nearest end of the siding board.

2) Pry the end of the board away from the house and put a block behind it. Be careful not to damage any building paper beneath the siding.

3) Shorten the board. Sometimes it’s easiest to do this with a saw; other times a rasp, plane, or perforated rasp works better. Allow about 1/16 inch of clearance to the next board.

4) Replace the board and re-nail it.

How to Caulk Siding Joints

Siding is most vulnerable to water infiltration at vertical joints, such as where doors and windows intersect, or where siding boards butt against one another. Tube caulking is easy to apply, and it’s available in colors to match natural or painted finishes.

Choose a quality caulk that will maintain its elasticity over a range of temperatures. Cut the tube’s tip at a slight angle, and push it into the joint as you apply the caulk.