Barbed wire and high-tensile smooth wire are the cheapest ways to fence large pastures for cattle, horses or sheep. A wire fence uses far fewer materials per foot than wood or mesh, but you still need to know how many rolls, posts and staples to order.
The calculation
Wire = fence length × number of strands × (1 + extra)
Rolls = wire ÷ wire per roll, rounded up
Line posts = fence length ÷ post spacing + 1
Add extra posts for corner and end brace assemblies and for gates. A typical H-brace uses two or three posts.
Typical setups
| Livestock | Strands | Post spacing |
|---|---|---|
| Cattle, barbed wire | 4 to 5 | 10 to 16 ft |
| Horses | smooth or coated wire, never barbed | 10 to 12 ft |
| Sheep and goats | woven wire or 6 to 8 strands of electric | 8 to 12 ft |
Barbed wire is usually sold in rolls of 1,320 ft (a quarter mile) of 12.5 gauge double-strand wire. High-tensile smooth wire comes in 4,000 ft coils.
Example
A quarter mile (1,320 ft) of 4-strand barbed wire fence takes 5,544 ft of wire with 5% extra, so 5 rolls of 1,320 ft. With line posts every 12 ft, you need 111 posts, plus 8 for braces: 119 posts and about 476 staples.
Posts
Wood posts 4 to 6 in in diameter are driven or set about 2.5 to 3 ft deep; corner and brace posts are larger and deeper, because they carry the whole tension of the wire. Steel T-posts are cheaper and quicker to drive for line posts. On long straight runs, add a brace assembly every 650 ft or so.
Building tips
- Stretch the wire from a solid brace with a fence stretcher, and keep it tight but not overstretched; barbed wire should not be stretched over about 250 lb.
- Staple wire on the livestock side of the posts, and do not drive staples all the way in on wood posts, so the wire can move with temperature.
- Wear heavy gloves and eye protection when handling barbed wire.
Check local rules on boundary fences: many states have fence laws that define a legal fence and how neighbors share the cost.