Putting it all together
Planning is essential. Mark out the line of the fence, keeping it as straight as possible to minimise pressure points. Every corner means another stay assembly, which is more expense.
Install end posts at least one metre in the ground. For maximum strength the post needs to be driven into the soil using a pilot hole as a guide. This requires a tractor powered post-hole digger and driver.
Alternatively the holes can be dug by hand and the soil rammed back around the post using a crowbar. In some unstable soil sites it may be worth considering concreting the posts into the ground.
To get all intermediate posts aligned between the two end posts use a helper and an optical aid such as an automatic level.
Another method is to strain a sight wire or the top wire between the two strainers, shaking it to make sure it is lying straight on the ground just as you might do with a stringline.
Put in the intermediate posts, if using steel posts these are driven in using a post knocker.
Concrete or wooden posts will need to be dug in or driven in using a mechanical driver.
Prefabricated fences are tied off onto one of the end posts and rolled out to the next post. If the distance is greater than one roll, join it to another roll and continue until the next post is reached.
When straining up prefabricated fences it is wise to use a multiwire strainer. This grips all the wires in the roll simultaneously ensuring an even tension.
The strainer is fitted to the wire a few metres before the second strainer and tension applied. This can be carried out with a tractor or four-wheel-drive.
After the first strain, the roll needs to be lifted and shaken along its length to free it from any obstructions on the ground.
Judging when the correct tension is reached can be tricky but there are several tools on the market which can help.
With prefabricated wire one simple method is to note the change in crimp shape in any of the line wires. When the crimp is half flattened the tension is generally sufficient.
When no crimp can be seen, then the tension in the wire is too high and needs to be reduced.
The loose ends of the line wires can now be tied off on the second end assembly and the tension on the strainer released.
A commonly used method of straining plain and prefabricated wire is to use a wire joiner as a tensioning device that fits permanently on the fence allowing the wire to be restrained at a later date.
To join rolls, use wire connectors and pretension using a multiwire strainer. The multiwire strainers are removed from the wire and the end tied off on the second end assembly.
Then, using single wire strainers, the individual line wires can be tensioned at the join of the rolls.
Using plain wires follows a similar process except that the wires are rolled out and strained one at a time.
When using steel intermediate posts it is important to not run the wire through the holes in the post — tempting as it may be. This will damage the galvanised coating on the line wire, shortening the life of the wire.
The final job is to tie off the line wires onto the posts and droppers.
Remember when using wire ties on steel posts that one side of the tie needs to go under the line wire and the other side over the line wire to hold it securely in place.
The finished product should be a quality fence capable of managing your livestock and preserving a healthy relationship with your neighbours!
What you will need
To construct a fence you will need the following:
- a helper
- posts (strainers and drop posts)
- post hole-digger
- crow bar
- safety glasses
Tying the knot
Traditional knots are the cheapest method of joining wire but some knots are better than others. The strongest knot for all types of wire is the figure eight (below), but it is not suitable for all applications.
Tying the knot requires some extra length in the wire, but the wire will usually slacken by about 50mm after wire strainers are removed so this makes the knot unsuitable when straining short lengths of fencing.
A better knot in this situation is the double loop knot (below) which is easier to tie but can reduce fence strength significantly.
Another option is the pin and loop knot (below). While more complicated to tie this knot is stronger under tension than the double loop.
The Donald knot (below) is stronger than the double knot, but needs to be tied tightly to avoid unravelling under tension.