how to jack up deck to replace post

3 min read 12-01-2025

Replacing a deck post is a crucial maintenance task that ensures the safety and longevity of your deck. This process often requires jacking up the deck section to access and replace the damaged post. While it might seem daunting, with the right tools and approach, it's a manageable DIY project. This guide will walk you through the steps, ensuring you complete the job safely and effectively.

Assessing the Situation: Before You Begin

Before you grab your tools, carefully inspect the deck and the post needing replacement. Determine the extent of the damage and the best approach for jacking.

1. Identify the Affected Area

Pinpoint the exact location of the damaged post and the section of the deck supported by it. You'll need to isolate this area to work safely and effectively.

2. Gather Necessary Tools and Materials

You'll need these essentials:

Jacks: Several heavy-duty car jacks or a post jack. Choose the type best suited for the weight of your deck section. Consider using multiple jacks for better stability and distribution of weight.
Cribbing: Solid blocks of wood (4x4s are ideal) to provide stable support for the jacks and the deck.
Level: A sturdy level to ensure the deck remains level during the jacking process. An accurate level is essential for preventing structural damage.
Post removal tools: Depending on the post type, you may need a saw, hammer, pry bar, or other tools to safely remove the old post.
New post: Ensure the new post is the same size and material as the old one. Treat the new post with appropriate wood preservative.
Post base and fasteners: You'll also need a new post base and appropriate fasteners (concrete, bolts, etc.)
Safety gear: Wear safety glasses, work gloves, and sturdy footwear.

3. Prepare the Work Area

Clear the area around the post to be replaced. Remove any obstacles or items that could interfere with the jacking process. Ensure the ground is level and stable enough to support your jacks.

Step-by-Step Guide to Jacking Up the Deck

This process requires careful attention to detail to avoid damage or injury.

1. Securely Position Jacks and Cribbing

Carefully place your jacks under the deck joists near the damaged post. Use the cribbing to distribute the weight evenly and provide stable support. Ensure the jacks are positioned correctly to lift the targeted section.

2. Gradually Jack Up the Deck

Slowly raise the deck section using the jacks. Work in small increments, constantly checking the levelness of the deck. Avoid sudden or jerky movements. Having a helper can make this easier and safer.

3. Secure the Raised Section

Once the deck is raised high enough to remove the old post, carefully secure it in place. Use additional cribbing to support the raised section and prevent it from dropping. Remember safety first!

4. Remove the Damaged Post

Carefully remove the damaged post. Depending on its condition and type of attachment, you may need to saw, pry, or hammer it out.

5. Install the New Post

Place the new post in position. Ensure it's properly aligned and plumb. Secure the new post with appropriate fasteners according to your deck's design and local building codes.

6. Lower the Deck Slowly

Carefully lower the deck section onto the new post. Again, work slowly and steadily, constantly checking the level using your level.

7. Final Checks and Clean Up

Once the deck is lowered, check its levelness and stability. Ensure the new post is firmly secure. Finally, clean up the work area and dispose of any debris.

Troubleshooting and Safety Tips

Uneven Lifting: If the deck lifts unevenly, adjust the jack placement and cribbing.
Excessive Weight: If the deck section is too heavy for your jacks, consider using a more robust jack or seeking professional help.
Safety First: Always prioritize safety. Use proper safety gear, work with a partner if possible, and never work under a raised section of the deck without proper support.

Replacing a deck post is a significant undertaking. While this guide provides a comprehensive overview, if you're unsure about any aspect of this process, it's always best to consult with a qualified professional. A structurally unsound deck can be dangerous, so prioritize safety and quality workmanship.