Farm Fence Post Spacing Guide: How Far Apart Should Your Posts Be?

FENCING RESOURCES

Setting out a new farm fence? The question we get asked most is: how far apart should I space my posts?

There’s no single number, because spacing depends on what you’re fencing in, the country you’re fencing over, how many wires you’re running and how hard your stock works a fence. But there are proven rules, and this guide lays them all out: what to consider, plus a spacing chart you can work from on the most common jobs.

The short answer: On most Australian farm fences, 4 metres between star pickets is the sweet spot. Stretch to 5 metres for crop fencing on firm flat ground, tighten to 3 metres for cattle on hilly country. On long straight runs, drop in an inline strainer roughly every 100 metres. And remember the strength of your fence lives in the strainer posts, not the pickets: put one at every corner and gateway, and wherever the topography changes.

THE BASICS

Where Do I Start? The Two Posts That Make A Fence

First, understand that a farm fence uses two different types of posts, and they do different jobs.

Strainer posts keep your wire fence tight and upright. A strainer is an anchor point for the wires. Wherever anything changes along the fence line, the wires need to be anchored so they hold the same distance and the same strain.

Star pickets guide the line of the wires and provide additional support between strainers.

For both, the distance between posts comes down to four things: how heavy the fence is, the stock being fenced in or out, the topography of the land, and any changes in direction. But because strainers and pickets play different roles, you space them by different rules. Here’s the chart, then the reasoning.

THE CHART

Fence Post Spacing Chart

Star picket and strainer post spacing for common fencing jobs. Roadside rules vary by state, so always confirm with the road authority before you build.

Those numbers cover most jobs. The rest of this guide explains the why, so you can adjust with confidence when your paddock doesn’t match the chart.

PICKETS

What Impacts Star Picket Spacing?

The Number Of Wires On Your Fence

A big wire count, say 9 to 12, needs as much support as it can get. Your pickets will need to be closer together to carry that extra weight.

Livestock Size and Pressure

Large stock like cattle lean on fences, so pickets need to be closer together to take the pressure. Barbed wire helps as a deterrent, but you still want the added strength. Smaller stock like sheep and goats let you space pickets further apart.

Terrain

Flat country lets you run more space between support pickets. Hilly country needs more pickets so the fence follows the contours of the land, and the significant dips and rises need more than a picket. More on that below.

STRAINERS

What Impacts Strainer Post Spacing?

Does Type Of Livestock Matter?

Livestock type changes your picket spacing, but it doesn’t really affect your strainers. Use strong steel strainer posts of 80NB (89mm O.D.) or larger and the post will carry the fence. It won’t matter if you have cows or chickens.

The Topography Of Your Land

Any significant topography change calls for a strainer.

If your fence dips into a gully, put an inline strainer at the bottom of it. A star picket down there would be pulled straight out by the strain of the wire. A strainer holds tight.

Same logic at the top of a hill, in reverse. Use an inline strainer on the crest so the strained wire doesn’t drive the post into the ground.

On a dead flat plain running straight, with no hills or dips, you can easily get hundreds of metres between strainer posts.

SOIL

Do Ground Conditions Affect The Spacing Between Posts?

Ground conditions matter, but not the way most people think. The instinct is to add more posts. What actually counts is the depth of the posts.

In black soil or clay country, use longer posts that reach down to solid ground, or go for Drive-Tight® end assemblies that give you more anchorage. In sandy soil, set your posts deeper rather than adding more strainers. Rocky ground is harder to drive into, but the rock repays you: it gives the posts extra support and makes the whole fence stronger.

One trap worth calling out: crop fencing country. It’s usually flat, low-stress fencing, so most people figure 5 metre picket spacing is fine. On firm ground, it is. But cropping soil is often deep and soft and holds moisture, and in that ground widely spaced pickets can’t hold a straight line. Give it a few seasons and the whole fence leans over. If your ground is soft and wet, bring your pickets back to 4 metres.

SPECIAL CASES

Barbed Wire And Exclusion Fencing

Does barbed wire change your post spacing?

Not really. A barbed wire fence follows the same spacing rules as a plain wire fence: the spacing is set by your stock and terrain and how many wires you run, not by the barbs. So a 5 strand barbed wire cattle fence on flat ground still runs 4 metre picket spacing (3 metres on hilly country), with the same strainer rules as the chart above. The barbs discourage stock from leaning on the fence, which helps the fence, but don’t use them as an excuse to stretch your spacing.

Exclusion fencing

Fencing pests out is a different job to fencing stock in. Pigs and kangaroos hit a fence harder than sheep ever will, and they probe it constantly. Keep your picket spacing at 4 metres or less under real pest pressure, and don’t skimp on the end assemblies, because an exclusion fence only works while it’s tight.

THE METHOD

How To Build A Wire Fence: Our Fencing Tips

1.

Strainer posts first.

Plan the fence by marking out where the strainers go: the ends of the fence, the corners, the gateways and every change in direction or topography. Can you kill two birds with one stone by putting a gate where the fence changes direction? On long runs with no corners or gates, drop in an inline strainer every 100 metres or so, and a bit closer in high-pressure spots like a laneway into the yards, or wherever rowdy cattle work the fence. So a 300 metre stretch on flat terrain at 4 metre picket spacing needs an inline strainer every 100 metres, with pickets every 4 metres in between.

2.

Space your pickets out evenly.

Even spacing between strainers gives the fence even strength and support along its whole length. And it looks better too.

3.

Always double check.

It’s easy to knock in another strainer when there’s no wire and no strain. Once the fence is wired up and strained, changes are a nightmare. Check your placements before you strain, do it once and do it right.

4.

Consider what’s in your neighbour’s paddock.

On boundary fences, what’s on the other side matters as much as what’s on yours. If the neighbour runs Brahmans and you’ve spaced for a light three wire fence, you’re building yourself years of headaches.

QUICK ANSWERS

Fence Post Spacing FAQs