How to repair rotten weatherboards

Updated November 21, 2016

Rotten weatherboards can cause many problems for homeowners. In addition to cosmetic issues, compromised weatherboarding creates an entry point for insects and rodents, and is a breeding ground for potentially dangerous mould. Repairing your rotten weatherboards increases your house's longevity as well as its appraisal value. Fortunately, a damaged weatherboard can be replaced with a minimal amount of remodelling experience, and without significantly affecting the surrounding boards.

Remove the damaged weatherboarding, as well as any undamaged weatherboarding surrounding the affected area. Apply gentle pressure to the seams between the weatherboards using a crowbar until the nails loosen. Discard the damaged weatherboarding. Remove the nails from the undamaged weatherboards and set them to the side.

Examine the area behind the weatherboards for water damage. If there appears to be warping, heavy discolouration or extensive rot or mould, consult with a professional before proceeding.

Lay the damaged weatherboard on top of a new piece of weatherboarding. Use a pencil to mark the edge lines of the damaged weatherboard onto the new piece.

Cut the new weatherboard to length, using a circular saw.

Locate the studs in the damaged section of the wall, using a stud finder. Mark the edges of each stud with a pencil.

Reinstall the weatherboarding. Work from the bottom piece up toward the top, nailing each piece of weatherboard at the top of the strip using a hammer and 3/4-inch nails. Drive your nails into the marked studs to ensure a secure installation. If there is weatherboarding still in place above the damaged area of the wall, you might need to loosen it slightly in order to slot the lower pieces back into place.

Seal all seams around the new weatherboarding with a high-quality, clear silicone caulk. Allow the caulk to dry thoroughly.


Always take appropriate safety precautions when using a circular saw. Pull back long hair, remove jewellery and wear safety glasses.

Things You'll Need

  • Crowbar
  • Pencil
  • Circular saw
  • Stud finder
  • Hammer
  • 3/4 inch nails
  • Silicone caulk
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About the Author

Michael Cohen has been a technical writer since 2006. His areas of expertise include classical music and nonprofit management, and his work has been featured across a variety of media platforms. Cohen received his bachelor's degree from The New School in New York City.