Repairing Water Damaged Wood

Rotten fascia board on eaves.

If water damaged wood isn’t providing structural support on your home, it can often be repaired using auto body filler, which is often easier than replacing the entire piece.

To repair water damaged wood using auto body filler:

  1. Remove any rotten wood from the water damage wood.
  2. Mix up auto filler putty with hardening cream following the directions on the container.
  3. Fill the hole before the filler has time to set.
  4. Apply additional coats of filler if needed.
  5. Sand the filler flush with the wood surface.
  6. Prime and paint over the filler.

Watch this video to find out more.

Further Information


If water damaged wood on the outside of your house doesn’t provide structural support it can often be repaired with auto body filler to avoid removing the whole piece. Clean out the rotten material so the filler will stick to good wood before mixing the filler putty with the supplied hardening cream.

Then fill in the damaged area, but work quickly because the body filler dries fast. Some repairs may require multiple coats of body filler. When it dries, sand it down flush with the surrounding wood, and you’re ready to repaint.


  1. Telling people to fix water damaged wood with bondo is BAD practice and actually worsens the problem. Bondo works on cars because metal and plastic don’t expand and contract with moisture. It only “works” on wood for one maybe 2 seasons. Plus you haven’t stabilized the wood with a hardener. And ideally you should use a borate wash compound to eliminate and prevent any mold and bacteria. Then you use a good – real – wood epoxy filler, such as Abatron.
    These steps are fast and easy and, most importantly, work long-term.

  2. This is some really good information about water damage. It is good to know that it would be smart to remove any rotten wood from water damage. It does seem like wood affected by water damage would become unstable.


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