Why does my wire go slack?
In this post we will talk about 3 possible reasons why high tensile wire can go slack after time.
Has your wire been over tensioned?
High tensile plain coiled wire should be tensioned to a max of 200kg, this can be difficult to gauge visibly, tension gauges tend to be the best way to test the wire has the correct tension.
What time of year was it erected?
If the wire was tensioned in the summer months and tensioned tight, the wire has nowhere to go when there is climatic change. The same can be said if installed in the winter, the wire will expand and contract.
(It is for this reason tension curves are built in to stock fence (the slight bend in the top/bottom wires). These tension curves should only be pulled out 50% to allow the wire to expand/contract to climatic change. )
What staples were used?
Staples should never been driven all the way in, high tensile line wire needs to be able to flex its full length.
Barbed staples are the most commonly used staple for this purpose, the simple double barbs bite into any timber type, the barbs act like an anchor preventing the staple from pulling out even when under pressure. These are also suitable for standard fencing when using softwood or chestnut, the barbs give better holding should the timber start showing natural signs of drying out and exposing splits.
The best method to prevent single line wires from going slack and to make sure you get the correct tension is to use a tension spring at the end of the lines. This is not only a visible indicator of the amount of tension applied but it also allows the wire to contract/expand under different temperatures. These can be used in conjunction with a wire tensioner to allow for fine tuning when needed.