Almost every property is fenced in some way, and nearly every fence has gaps in it, whether it is the spacing between boards or the open weave of a mesh fence. We see them everywhere, so it is easy to walk past without wondering why they are there. But the gaps are deliberate, and if you ignore them when planning a fence you can end up with problems.
First, what is the fence for?
Before you decide how open or closed a fence should be, it helps to be clear on why you want it.
- Protection. A fence is the first line of defence against trespassers, and it keeps animals out of a garden or yard. For that it needs to be sturdy enough to actually stop something.
- Privacy. A fence screens your yard from the street and the neighbours. The more you want screened, the more solid and the taller it needs to be.
- Appearance. A well-designed fence lifts the look of a property. If that is the goal, the spacing and pattern become part of the design.
What the gaps are actually for
Once you know the job, the gaps start to make sense. There are three main reasons fences are built with them.
- Airflow. Gaps let air move through the space a fence encloses. The bigger the gaps, the more air gets through, which matters for yards that cop a lot of heat and would otherwise sit still and stuffy.
- Room for movement. Timber swells and shrinks with moisture. Leaving space between boards gives the material room to move without buckling or splitting the fence. Metal moves less, but the principle holds.
- Wind load. This is the big one. A solid fence takes the full push of the wind like a sail, which is hard on posts and footings. Gaps let air pass through, so the fence sheds the load instead of fighting it. In an exposed spot that is the difference between a fence that stands and one that blows over.
Chainwire takes it to the extreme
If gaps are good for airflow and wind, chainwire is the logical end of the idea. Its open diamond mesh is almost all gap, so wind passes straight through and there is next to no sail area to worry about. That is a big part of why chainwire, also called cyclone or chain mesh fencing, holds up so well on exposed rural blocks, sports grounds and coastal sites, and why it needs far lighter posts and footings than a solid fence of the same height.
So something as ordinary as a gap turns out to matter. Before you settle on a fence, be clear on what you want it to do, then choose the spacing, or the mesh, that suits the site rather than fighting it.