How to Repair Rotten Fence Posts

One of the disadvantages of a wood fence post is the chance it may rot, and many fence posts rot around their base where the wood is routinely exposed to ground moisture.

Wood posts are subject to rot.Wood posts are subject to rot.
Fence posts with rotten bases need not be completely replaced, however. The rotten base can be removed and replaced with a metal fence post spike, extending the life of the remainder of the wood fence post. This task of repairing a rotten fence post requires only a few tools, and does not even require taking down much of the fencing.

Detach the fence panels or planks from the rotten fence post by striking with a hammer the areas where the plank or panel is attached to the post by nails. Use one hard blow to loosen each plank or panel, then remove it with steady taps. You may wish to use a rubber mallet for part or all of this step, to avoid damaging the panel/plank.

Lay the ends of planks or panels removed from the post on the ground a short distance from the rotten post so that they are not in your work space.

Cut off the fence post from its rotten base using a hand or reciprocating saw. Make sure to cut high enough to remove all rotten wood from the fence post. Set the fence post aside.

Trim the rotten base with the saw so it has a reasonably level top that is more or less flush with the ground.

Place a wood block inside the cup at the top of your fence post spike, and then put that spike atop the rotten base.

Strike it with the hammer to drive the spike an inch into the rotten wood, so that it stands on its own, then drive the spike the rest of the way with a sledge hammer. Take care to adjust your hammer blows to keep the spike straight and level on the way down.

Place the post in the fence post spike and mark spots through the screw holes on the bottom of the spike's cup onto the post with a marker.

Remove the post and drill holes into the marks made on the sides of the post.

Replace the post into the spike's cup and align the holes in the cup with the newly drilled holes in the post.

Fasten the post to the spike with screws and a screwdriver.

Reattach the panels and posts by driving the old nails back into the fence post with a hammer.

Things You Will Need

  • Claw hammer
  • Rubber mallet
  • Hand saw or reciprocating saw
  • Metal fence post spike (size should match the diameter of the fence post)
  • Wood block
  • Sledgehammer
  • Marker
  • Drill
  • Wood screws
  • Screwdriver
  • Bar wrench (optional)

Tip

  • If your fence post spike becomes misaligned as you drive it into the ground, you can readjust it with a bar wrench. Clamp the bar wrench onto the spike's cup and nudge it into the right position by pulling.