In this video, This Old House landscape contractor Roger Cook replaces rotted wood on a split-rail fence.
1. Carefully dig up all plants that are close to the damaged fence post.
Wrap the plants in burlap and set off to the side.
2. Use a pointed shovel to dig around the old, rotted fence post.
Dump the dirt onto a burlap sheet spread onto the ground.
3. Remove the old fence post, then enlarge the hole with post-hole digger.
Again, dump the dirt onto the burlap.
4. Cut a new fence post to proper length with a chainsaw.
5. Stand the post in the hole, attach the fence rails, then backfill around post with dirt.
6. Use a 4-foot level to ensure the post is plumb (perfectly vertical).
Firmly compact the dirt around the base of the post.
7. Stretch a nylon string between the new post and nearest existing fence post.
8. Set intermediate posts into their respective holes, then mark height at the string and cut them to length with a chainsaw.
9. Insert fence rails into both sides of the final post.
Backfill and tamp the soil to hold the post plumb.
10. Re-plant the plants that were dug up earlier.