How to Repair Rotting Wood Siding

Wood siding, properly maintained, can last for decades once mounted in place.

Repair wood rot in your siding by replacing the damaged areas.Repair wood rot in your siding by replacing the damaged areas.
Unfortunately, damage can occur to even the best-maintained siding. For wood siding, the smallest of damage can provide an opening for moisture, leading to wood rot. Caught early, a small rotting portion of siding does not mean the siding itself must be replaced. You can cut out the rot and replace the damaged area, saving the rest of the plank while preventing the spread of the rot at the same time.

Examine the damaged plank to determine the full extent of the rotted area. Place marks on both ends of the rotted section about ½ inch into the undamaged wood, running the full height of the plank.

Cut the plank along the marked lines with a circular saw set to a blade depth slightly less than the plank’s width. Remove the nails securing the cut portion of the plank to the building using a claw hammer. Use a hammer and chisel to finish the cut through the plank, then pry it from the surface of the building. Dispose of the rotted wood.

Paint the exposed edge of the plank with paint the same color as that already covering the panel. The paint will provide a protective layer for the exposed edge from the elements. Allow the paint to dry for two hours.

Cut a new plank portion to the size of the removed rotted wood. Measure the empty space and cut the new plank to size with the circular saw. Paint the edges of the new plank and allow it to dry for two hours.

Slip the replacement plank beneath the lower edge of the plank in the row above. Place the groove running along the length of the bottom of the replacement plank onto the top edge of the plank directly under it. Nail the new plank into place, using 2 ½-inch siding nails placed into each wall stud spanning the replacement area. If the edges of the replacement plank overshoot a stud, nail it directly into the house sheathing using 1 ¾-inch nails. Make sure the siding is made of wood first and that it’s at least 5/8 inch thick.

Paint the replacement plank the same color as the surrounding planks to protect it from the elements.

Things You Will Need

  • Circular saw
  • Hammer with claw
  • Chisel
  • Paint
  • Paintbrush
  • Measuring tape
  • Replacement siding panels
  • Siding nails


  • Nail the siding loosely but securely to the wall to allow for expansion space for the siding.

About the Author

Larry Simmons is a freelance writer and expert in the fusion of computer technology and business. He has a B.S. in economics, an M.S. in information systems, an M.S. in communications technology, as well as significant work towards an M.B.A. in finance. He's published several hundred articles with Demand Studios.