Chainwire is durable stuff. The galvanised wire is close to corrosion proof and a good fence lasts for decades. But over time the weave relaxes and the mesh starts to sag, especially where the fence gets climbed on or copes with rough weather. A loose fence is easier to get under or over, and near children a droopy bottom edge is a hazard. The good news is that tightening a chainwire fence is usually a straightforward job.
A chainwire fence is a system
The mesh on its own is too flexible to hold a line. What keeps it tight is the framework around it: the terminal posts, the line posts and the top rail give the mesh its support, and a tension wire along the bottom holds the base in place.
That bottom tension wire is what keeps animals from pushing under and stops the mesh bending out at ground level. A good installer runs it at the time the fence goes in. Plenty of DIY fences skip it, which is exactly why they sag within a season or two. If your fence has no bottom tension wire, adding one is the first thing to do.
What you need
You can tension most chainwire fences with a few common tools:
- pliers
- bolt cutters or wire cutters
- a come-along (a hand winch)
- tension wire
- brace bands and bolts
Installing or replacing the bottom tension wire
Cut the tension wire into suitable lengths, allowing extra rather than cutting it short. Leaving a bit spare is far less frustrating than trying to work with a wire that is too short, and the wasted material is minimal next to the aggravation of over-stretching a tight run.
- Attach the wire to a terminal post using a brace band. Form a loop in the end, thread the brace band bolt through the loop, and secure the assembly.
- Place a brace band on the far terminal post and thread the wire through it.
- Take up the tension. A common trick is a length of pipe with two holes drilled near one end: thread the wire through the holes, then turn the pipe to wind the wire on and pull the slack out.
- Once the slack is gone, wrap the loose end around the standing part of the wire and secure it back to the brace band bolt.
One thing worth knowing: the bottom tension wire does not need to weave through the diamonds of the mesh. It is tensioned first, then the mesh is clipped to it with hog rings at regular intervals, usually every 600mm to 900mm. That is what holds the base tight to the wire.
When to call a fencer
Tightening a short domestic run is well within reach for a handy owner. Where it is worth getting a crew in is when the posts themselves have moved or leaned, the top rail is bent, or a long commercial run has gone slack, because at that point the framework needs attention, not just the mesh. If you are not sure whether it is a quick tension job or a bigger repair, a look over the fence line will tell you fast.