Wire – Specification and Correct Installation
Pre-fabricated wire netting – High tensile
Hinge jointed – tensile strength 1235-1390 (N/mm2)
X Fence – tensile strength 1235-1550 (N/mm2)
Coating – Hinge jointed hot dip galvanised to BSEN min coating weight 245grm OR X fence - Alu/zinc coated min 5% aluminum is mixed with the zinc to provide a wire that will last up to three times longer than heavy galvanised wire.
Tension curves – All netting these days should come with tension curves between the vertical wires, these tension curves were introduced many years ago after much research. They are applied to the netting at the point of manufacture. Their sole purpose is to retain the tensile strength of the netting in climatic changes, i.e. the wire will expand and contract to a certain degree in hot and cold weather, the idea of the tension curve is it act like a spring. These spring like properties will make sure the wire netting retains its elasticity throughout its life. As a rule of thumb in order to get the correct tension of the netting 50% of the tension curve should be pulled out. At no point should the whole curve be pulled out or the use of mechanical machinery to achieve this. This may provide an immediate strained fence but this will slacken once the climate changes.
The correct tension for fabricated netting should be a maximum of 150kg, which can be tested using a tension indicator.
Single strand wire
High tensile wire – tensile strength 1235-1350 (N/mm2)
Coating – Hot dip galvanised exceeding BSEN10244-2 min coating weight 275grm or Alu/zinc coated min 5% aluminium is mixed with the zinc to provide a wire that will last up to three times longer than heavy galvanised wire.
Tensioning - With the lack of tension curves as an indicator it can difficult to gauge the correct tension.
There are several ways to determine the correct tension on single strand wire. Install a tension spring with one of the in-line strainers per section. This will help you gauge the wire tension. The tension spring is 225mm long; proper tension to a maximum of 200kg has been reached when the spring is compressed to 175mm.
Using Gripple wire joiners – which are designed to take up to 400kg strain maximum.
Use medium Gripples with a Gripple Torq Tensioning Tool, which not only tensions the wire but regulates the load applied too, delivering consistent results and maximising the life of your wire.
It’s the simplest laymen’s tool to make sure that the tensile strength is not being overdone, simple set the tension indicator to the tensile strength required, 150kg recommended, when the tool clicks out, the correct tension has been achieved.
If using the wire tension gauge the tension should be tested in the middle between the strainers.
Alternatively, use in line strainers with tension indicator springs, these springs give a clear indication of where the correct tension should be. They also help with climatic change, retaining tension on the single line wire fence.
Tension gauge marks, once taken to second mark the correct tension of the line wire has been achieved. If no marks, then compressed between 190-175mm maximum.
For more information on installation, watch the short video below.