Fence Post Repair vs Replacement: Which Does Your Fence Need?

TL;DR

If the post above grade is still solid and the concrete is cracked: reset the concrete or add a steel insert.

If the post is rotted at grade but solid above: install a steel post sleeve. Cheaper than full replacement, often stronger.

If the post is rotted throughout: full replacement. New wood or steel, new concrete.

Full replacement: $350–$550 per post. Steel insert: $275–$450. Concrete reset: $200–$350.

Steel posts and Simpson Strong-Tie Postmaster outlast any wood replacement.

A leaning fence is almost always a post problem — not a panel problem. Rails, pickets, and panels above the post are usually fine. The failure is at the post base where wood meets concrete or dirt. Figuring out whether you need a repair or a replacement comes down to what’s actually rotted.

The diagnosis

Stand beside the leaning post. Do three tests:

Test 1: Wiggle the post at chest height.

No give, just lean: the post is moving in its footing. Concrete issue.
Visible give, flexes near ground: the post is rotted at grade.
Whole post rocks in the concrete: concrete is cracked or soil has washed out.

Test 2: Inspect the base. Dig out 2–4 inches of soil at the post base. Look for:

Solid wood all the way into the concrete: Post wood is fine. Fix is concrete-related.
Soft, darkened, or crumbly wood at the soil line: Rot at grade. Classic fence failure.
Cracks in the concrete around the post: Concrete has failed; needs replacement.
Concrete intact but post rocks: Footing was too shallow or sandy soil eroded under the footing.

Test 3: Check the wood condition above grade.

Solid, dry, stain intact: Post wood above grade is fine.
Cracked, split, or twisted: Post wood itself is failing (usually from UV and weather, less common than base rot).
Rotted throughout: Full replacement.

Those three tests tell you which fix you need.

Fix type 1: Concrete reset (post wood is fine)

Scenario: The post wood is solid from top to bottom, but the concrete footing has cracked or shifted.

What’s involved:

Dig out around the concrete footing.
Break the old concrete with a mini sledge or cold chisel.
Remove concrete chunks.
Brace the post plumb.
Pour fresh 3,000-psi concrete to 30-inch minimum depth, crowned above grade so water sheds.
Let cure 24 hours before reattaching rails or pickets.

Cost: $200–$350 per post from a pro. DIY is possible with 2 hours of effort and $20 in concrete mix.

Works for: Any post where the wood itself is still solid but the concrete has failed.

Fix type 2: Steel post insert (rotted at grade, solid above)

Scenario: The post base has rotted at the soil line, but the upper 3–4 feet of post is still solid.

What’s involved: Install a galvanized or stainless steel post insert — Simpson Strong-Tie Postmaster, E-Z Mender, or similar. The insert:

Has a steel sleeve that bolts to the upper (solid) portion of the existing wood post.
Has a square steel base plate that sits on or in fresh concrete.
Replaces the rotted wood portion with a permanent steel section.

Installation:

Cut off the rotted wood portion of the post (usually the bottom 12–18 inches).
Excavate around the base.
Position the steel insert so the sleeve slides up onto the remaining wood post.
Bolt the sleeve to the wood with carriage bolts or lag screws.
Pour fresh concrete around the steel base, 30-inch minimum depth.
Brace plumb until concrete cures.

Cost: $275–$450 per post from a pro. DIY possible with basic tools and $30–$50 in parts.

Works for: Most leaning fences in San Diego. Cheaper and often longer-lasting than a full wood replacement.

Advantage: Steel doesn’t rot. The repair is usually permanent (20+ years) where the original wood failed in 7–10.

Fix type 3: Full post replacement

Scenario: The post is rotted or damaged throughout — not just at grade.

What’s involved:

Remove the old post and concrete completely.
Detach rails and any pickets attached to the post, preserving what can be reused.
Dig a new 30-inch-minimum post hole.
Set new post (cedar, pressure-treated, or steel) in fresh concrete.
Crown concrete above grade.
Reattach rails and pickets to the new post.
Match stain or finish to the surrounding fence.

Cost: $350–$550 per post from a pro, including material and reattachment.

Works for: Fences where the old post can’t be salvaged — multiple failure points, cracked throughout, or severe impact damage.

Advantage: Starting from scratch gives you the option to upgrade — 6x6 post instead of 4x4, steel instead of wood, deeper footing, stainless hardware.

Steel post insert vs wood replacement: which is better?

This is the question most homeowners want answered. Honest comparison:

Steel post insert:

Permanent (steel doesn’t rot).
Cheaper on install ($275–$450 vs $350–$550).
Preserves the existing fence panels (less disruption).
Hidden below the ground — invisible after install.

Wood replacement:

Familiar fix — looks like original construction.
Allows a full rebuild (new post, new hardware, matching stain).
No mixed-material look underground.
If using cedar or redwood, lasts 10–15 years.

In most San Diego scenarios, the steel insert is the better repair. It’s cheaper, stronger, and outlasts the fence panels above it. Full wood replacement only wins when the existing post is damaged beyond the ground line or when you’re rebuilding multiple adjacent posts.

When you need more than one post repaired

If 3 or more posts along a single fence run are leaning or rotted, the economics shift. At that point, it may be cheaper to rebuild the full run with new posts from scratch rather than patching 3 individual posts.

Rule of thumb:

1–2 posts: Individual repairs.
3–4 posts on a single run: Individual repairs if the panels are salvageable; full rebuild if panels are also showing issues.
5+ posts on a run: Full rebuild usually cheaper per linear foot.

A 150-foot fence rebuild with new posts runs $5,500–$9,500. Individual post repairs run $275–$550 each. Break-even is around 10–15 posts — so for a typical 15-post backyard run, if half the posts are failing, a full rebuild often wins.

Common DIY mistakes on post repair

Setting a new wood post in the old cracked concrete. The old concrete has already failed; it’ll fail again, faster.

Skipping the 30-inch footing depth. Shallow posts lean again within a year or two.

Pouring concrete directly over buried wood. Any wood below the concrete rots over time. Post bottoms should be in gravel or a concrete footing, not buried wood-to-dirt.

Using fast-setting concrete without enough depth. Fast-set is fine for small posts but needs the same depth to hold.

Not crowning the concrete. Flat-topped footings let water pool at the post base — accelerates rot. Always crown so water sheds.

Zinc-plated hardware in coastal zones. Corrodes fast. Stainless is required on the coast.

When post repair won’t save the fence

Sometimes the post is fine but the rest of the fence is dying:

Rails rotted at connections. Post fix doesn’t help if the horizontal rails are failing.
Pickets falling off in multiple sections. The underlying structure may be past the point where individual fixes add up.
Panels twisted or bowed. Often a sign that the fence wasn’t built straight originally.

If the whole fence is tired and the posts are just the most visible symptom, a full rebuild is often the better call.

What we do on post calls

Single-post calls we usually handle same-day or next-morning. Multi-post calls get scheduled within the week. We carry steel post inserts, replacement cedar and pressure-treated 4x4s, and concrete mix on the truck — most repairs are start-to-finish in under 4 hours.

If you’re not sure whether your fence needs repair or rebuild, send photos of the post bases and the overall fence condition. We can usually diagnose from photos and give a quote without a site visit.