If your fence is leaning, it may need a new post or two

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Q: One of our front yard fence posts isn’t holding up its end of the bargain due to old age. How can I quickly replace a rotten anchor post? 

A: This time of year in the beautiful Pacific Northwest, we spend more time outside with our focus drifting toward outdoor projects. Your fence sections may be weathered and gray, but cedar boards don’t typically need replacing.

If your fence is leaning significantly, it may be that a post has rotted and a simple post replacement is all that’s needed. Here’s how to replace an anchored post on a standard wooden fence.

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1. Remove the sections

To get to the post and provide working room, it’s necessary to remove the attached fence sections. First, remove all fence boards within 12 inches of the post. This will also need to be done at the next post on either side of where you’re working.

Next, use a Sawzall or other reciprocating saw with a blade for cutting metal. Insert the blade between the post and the section rail, and cut the nails off. Do this at the post you’re removing and at the post at the far end of the sections. Remove the section and set it aside for reinstallation.

2. Remove the post

Removing the old post base is a matter of digging it out. Soaking the ground with water may assist in the removal process. If the post proves difficult to remove, a lever can be created by driving large nails or screws into the base of the rotten post as the fulcrum before using a two-by-four to lift the post out of the hole. Existing concrete should come out with the rotten post, or crumble during the process for easy removal.

3. Replace the post

The new post should be the same size as the rotten post, with a pressure-treated, ground contact wood used. Make sure the new post rises above the top of the fence; it can be cut to size later.

Reinstall one of the sections using 3-inch outdoor screws through the side rail and into one of the existing posts exactly where it was positioned previously. (This is easier to perform with two people.) Then set the new post at the bottom of the hole against the section rails and secure the post to the section with screws.

The new post is now positioned exactly where it should be and won’t require measuring.

Take the next section and situate it between the old post and the new post. The new post won’t be stable, so have someone else hold it in place.

4. Secure the new post

Install a temporary brace to hold the post secure and aligned with the rest of the fence. Then it’s just a simple matter of filling the hole with concrete or gravel. (A level may be used to confirm that the post is close to plumb.)

Gravel will need to be applied in layers and tamped solid as you fill the hole again. You can purchase 60-pound bags of premix concrete. Dump the dry mix into the hole, and spray water as you fill the hole so the dry mix receives moisture.

5. Final steps

Cut the post at the height needed, reinstall any existing fence boards and remove the brace once the concrete is set. Finally, backfill the top of your hole. The replacement is now complete.

Posts are a crucial part of any fence, and this simple replacement technique will keep yours going for the long-term, so you can enjoy your yard and the outdoors even more while the sun is shining.

Daniel Westbrook writes for Dunn Lumber and is a member of the Master Builders Association of King and Snohomish Counties, and HomeWork is the MBA’s weekly column. If you have a home improvement, remodeling or residential homebuilding question you’d like answered by one of the MBA’s more than 2,800 members, write to homework@mbaks.com.