DIY Fence Post Repair: Fix a Leaning Fence in Under 3 Hours

Updated at: 19/05/2025

A leaning fence post not only detracts from your property's curb appeal but also compromises the structural integrity of your entire fence line. Ignoring the problem can lead to further damage, ultimately requiring a more extensive (and expensive!) repair down the line. But don't despair! Fixing a wobbly fence post is often a simpler DIY project than you might think, and can be accomplished in a surprisingly short amount of time. With the right tools and a little know-how, you can restore your fence to its former glory without breaking the bank or needing to call in professional help.

This article provides a straightforward, step-by-step guide that will have you tackling that leaning post and getting your fence back in shape in under three hours. Ready to get your hands dirty and reclaim your fence's stability? Let's dive into the process, equipping you with the knowledge and confidence to complete this repair quickly and efficiently.

Preparation and Safety Guidelines

Tools Needed
  • Shovels
  • Crowbar
  • Cement Mixer (or bar)
  • Level
  • Screws
  • Drill
  • Fast-Setting Concrete Mix
  • Water
  • 4x4 Post (10ft)
  • Measuring Tape
  • String
  • Saw
Safety Guidelines
  • Always wear appropriate safety gear, including gloves, safety glasses, and sturdy work boots. Loose clothing and jewelry should be avoided.
  • Before digging, call 811 (or your local equivalent) to have underground utilities marked. Hitting a gas line or power cable can be extremely dangerous.
  • Use caution when operating power tools. Ensure they are in good working order and follow the manufacturer's instructions carefully.

Step-by-Step Instructions

  1. Remove the Old Post

    • Remove the rotten 4x4 post.
    • Dig out the old concrete around the base of the post. Aim for roughly 14 inches by 24 inches deep.
    • Remove any obstructions, such as tree roots, that might interfere with the new post's placement.
    Remove any obstructions, such as tree roots, that might interfere with the new post's placement.Remove any obstructions, such as tree roots, that might interfere with the new post's placement.Remove any obstructions, such as tree roots, that might interfere with the new post's placement.
    Remove the Old Post

  2. Prepare the New Post

    • Cut the new 4x4 post to the desired length (8ft in this case).
    Cut the new 4x4 post to the desired length (8ft in this case).
    Prepare the New Post

  3. Set the Alignment

    • Set up a string line to ensure the new post is aligned with the rest of the fence.
    Set up a string line to ensure the new post is aligned with the rest of the fence.
    Set the Alignment

  4. Mix and Pour Concrete

    • Mix the fast-setting concrete according to package instructions, ensuring a consistent, workable mixture.
    • Position the new 4x4 post precisely using the string line as a guide, and fill the hole with the concrete mixture.
    Position the new 4x4 post precisely using the string line as a guide, and fill the hole with the concrete mixture.Position the new 4x4 post precisely using the string line as a guide, and fill the hole with the concrete mixture.
    Mix and Pour Concrete

  5. Level and Set the Post

    • Ensure the post is level in both directions before the concrete sets.
    Ensure the post is level in both directions before the concrete sets.
    Level and Set the Post

  6. Cure the Concrete

    • Allow the concrete to set completely. (approx 10-20 min for fast-setting mix)
    Allow the concrete to set completely. (approx 10-20 min for fast-setting mix)
    Cure the Concrete

  7. Reattach Fence Panels

    • Securely attach the fence panels to the new post using screws.

Read more: Reinforce Wobbly Deck Railings: The Lag Bolt Method

Tips

  • Use a small shovel for easier maneuvering in tight spaces.
  • Don't dig too wide around the old concrete to save space.
  • Mix the concrete to the right consistency – not too wet or dry.
  • Use a string line to ensure proper alignment of the new post.
  • Use fast-setting concrete to speed up the project.

Common Mistakes to Avoid

1. Insufficient Digging Depth

Reason: Setting posts too shallowly results in instability and further leaning over time, especially in challenging soil conditions.
Solution: Dig holes at least twice the depth of the post, ensuring a secure foundation in compacted soil.

2. Ignoring Existing Damage

Reason: Attempting to repair a leaning post without addressing rot, insect damage, or cracks leads to recurring problems and wasted effort.
Solution: Replace severely damaged posts entirely, and reinforce weakened sections with metal brackets or concrete.

3. Improper Post Straightening

Reason: Using brute force or inadequate support to straighten a leaning post can cause further cracking or damage to the post itself or neighboring fence sections.
Solution: Gradually straighten the post using temporary supports and leverage, ensuring consistent pressure to prevent sudden snapping.

FAQs

What type of concrete should I use to reset a fence post?
Use a quick-setting concrete mix designed for exterior use. Standard concrete mix works, but quick-setting allows for faster curing and less waiting time before the post is stable. Avoid using lightweight concrete, as it may not provide sufficient support.