Fence Post 101: How to Choose & Install the Right Posts
Posts Are the Backbone
Your fence posts support everything else. They need to be made of a durable material and installed properly — a weak post turns a good fence into a seasonal repair project. Before you choose, answer three questions: will the fence be permanent or temporary? What is the general layout (corners, gates, terrain)? What animals will it hold?
The Three Post Jobs
- Corner posts — usually wood, set deeper than in-line posts to withstand the strain of a taut fence line. A good rule: sink them about as deep as their above-ground height.
- In-line posts — spaced between corner posts to support the wire and stop sagging. They don't need to go as deep as corners but should be firmly set.
- Temporary / portable posts — smaller and lighter, used to section a pasture for rotational grazing. Most push into the soil by hand with a step-in flange.
Fence Post Types
| Post type | Best used for | Notes |
|---|---|---|
| Wood | Corner and permanent lines | Use at least 8 ft for corners; set 24–48 in deep (more in sandy or rocky soil) |
| Steel rebar / fiberglass rod | Temporary and portable fencing | Fiberglass is flexible but needs gloves; both work as in-line spacers |
| T-post | Permanent or semi-permanent in-line | Drive with a post pounder; pairs with clips and brackets |
| Step-in post | Rotational grazing, temporary lines | Lightweight, no clips or insulators needed |
| Pigtail post | Cross-fencing, managed intensive grazing | Top loop holds the line; no clips or insulators |
Recommended Post Spacing
| Fencing type | Spacing (feet) |
|---|---|
| Woven wire | 14–16 |
| Barbed wire | 12–14 |
| Electric | 12–20 |
| High-tensile, level terrain | 30–90 |
| High-tensile, difficult animals / rolling terrain | 15–20 |
| Polytape and polywire | 12 |
| Board | 8 |
| Corrals | 6 or less |
Choosing Wood Posts That Last
Wood decays over time — untreated wood typically fails in just a few years. Look for pressure-treated wood (CCA or equivalent), and check the retention rating: 0.4 lb/ft³ or higher indicates enough treatment to last decades. Anything lower will break apart fairly quickly.
| Wood type | Untreated (years) | Treated (years) |
|---|---|---|
| Pine (most common) | 3–7 | 25–30 |
| Cedar | 15–20 | 20–25 |
| Redwood | 10–15 | 20–30 |
| Black Locust | 20–25 | Treatment not necessary |
| Osage Orange | 20–25 | Treatment not necessary |
| Oak (white) | 10 | 15–20 |
| Sweetgum | 3–6 | 20–30 |
| Douglas Fir | 3–7 | 15–18 |
Two species — Black Locust and Osage Orange — resist decay so well they don't need treatment at all and can last up to 25 years. Avoid "landscape timbers", which are often unlabeled and not built to carry fence tension.
Metal Posts: Know the Trade-Off
Metal posts are fine for ornamental or chain-link fencing, but for livestock lines they are usually inferior to wood — especially as corner posts. Metal doesn't flex: once bent, it stays bent. Animals testing the fence will eventually push a metal post past its limit and you'll have to replace it. Wood flexes and returns to shape, which is exactly what a fence under pressure needs. For corners, sink the post about as deep as its above-ground height; in-line posts can go shallower.
Putting It Together
Match the post to the job: wood corners and T-posts for permanent lines, step-in and pigtail posts for rotational grazing. Spacing follows the fence type in the table above — more posts than needed wastes money, too few lets the line sag and short out. For the full install sequence, work through our installation guides.