Call it what you like: 358 fence, 358 security mesh, prison mesh fencing. There’s no denying that 358 mesh fences have become a go to for high security perimeter fencing.
It’s been around for a while, but if you’re still not sure exactly how 358 fence works, or where you should install it, you’re in the right place. Read on to find out what you need to know about 358 mesh or prison mesh fencing, and everything related to it.
The first thing you probably need to know is why it’s called 358 mesh to begin with – and it’s all about dimensions.
The standard mesh aperture size for prison mesh fencing is 3 inches wide by 0.5 inches high, and it’s made from 8-gauge wire. So, when the product was named, it was simply named for the dimensions of the mesh.
358 mesh is a very precise product, and each wire intersection needs to be welded, so of course, it wouldn’t be feasible to do this by hand!
Instead, 358 mesh manufacturers have large machines that position and electrically weld each wire intersection precisely. This ensures that every wire is perfect spaced and every joint on the panel is securely welded.
358 mesh is usually made from mild steel wire, but there are a variety of wire coating options.
You could choose an ordinary galvanized panel for noncorrosive environments, or you could opt for a hot dip galvanized panel. There are also zincalum panels, which are coated with a corrosion resistant mixture of aluminum and zinc. These are usually better for highly corrosive environments.
There are also a variety of paint and powder coating finishes available. These are applied after the panels are made, and over the galvanizing or zincalum, and panels can usually be coated in a wide variety of standard and custom colors, depending on the volume being ordered.
One of the biggest challenges to designing, manufacturing and installing a 358 fence is the weight of the panels. This is about 9.6 kilograms per square meter of panel. That’s over 21lbs!
A standard 2.4 x 2.4m or 8 x 8’ panel will weigh 55.57 kilograms or over 122lbs.
This means that the structure of the fence needs to be designed to carry a lot of weight, and it can be tricky to get the fence panels into the right position and hold them there while you fasten them in place.
In some parts of the world, believe it or not, a standard 358 mesh prison mesh fencing panel might not be enough to secure a site.
Which is why some companies developed “double skin” panels. These are panels that have a second “layer” of wires welded to each side, reducing the aperture size dramatically, and making the panels much heavier and stronger.
In most cases, ordinary 358 mesh fence will do the job well. But it’s nice to know that there are alternatives out there if you need them!
Yes, in theory, you can curve 358 mesh panels, and there are fence systems like the bowed fence or curved fence systems that are installed at prisons in South Africa and elsewhere where that is done.
The general rule of thumb is that if you want to curve panels it should be along the standard “height” of the panel, and that the radius of the curve should be large and gentle.
If you want to install a bowed 358 fence, it’s a good idea to defer to the experts for design and specifying advice. This is not an easy task!
There are many kinds of structure that could be used for 358 mesh fence systems, such as:
Because of the weight of 358 mesh panels, standard fence structural components will not be strong enough for this kind of fence. So, if you are planning to install a fence like this, you should get advice to engineer the structure properly.
Yes. Any fence can be cut. However, it’s a lot harder to cut 358 mesh fences than other fence types.
First, there’s the problem of space. You need space to get wire cutters around wires, and with only 0.5” between wires on a 358-mesh fence, there’s not a lot of that.
Then there’s the wire itself. It’s over 4mm or 8 gauge thick. Which means you would really struggle to cut them by hand, and even if you only had to create a 12” hole, you’d have to cut 24 wires on only one side! That would take a long time, and by that time, site security is very likely to have caught up to you already.
However, if someone had an angle grinder and the time to make a lot of noise and sparks cutting through the fence, they could do it. You would be able to see the hole instantly though – there’s no disguising a hole in a high security welded mesh fence!
Most sites that use 358 mesh fencing don’t give people enough time to do that though, and that kind of noise and disruption would almost certainly be spotted.
So, can you cut a 358 fence? Yes. In theory. But you probably wouldn’t be able to do it without being caught, and definitely not with hand tools.
358 fence or prison mesh fencing as it’s known in some parts of the world is often marketed as a high security anti climb mesh fence.
That doesn’t mean that it can’t be climbed at all. But it is a whole lot harder than climbing any other kind of fence, and again, it’s all about the mesh aperture.
It’s very hard for most people to get their fingers into a 0.5mm gap and get enough grip to climb! Of course, if you had a ladder, which wouldn’t be a problem, but since most 358 fences are installed with fence top security like razor coils or electric fence, you’d still struggle to get over quickly.
There are lots of challenges involved in installing 358 fences, which is why the labour costs are higher for this type of fence too.
If your fence structure uses holes with predrilled or pre slotted holes, you need to make sure that they are installed at the right height, and of course, they need to be completely plumb to ensure that panel wires, cover strips and posts line up correctly.
Posts also have to be installed at the correct centers to ensure that all the holes, wires and bolts are lined up.
Then there’s the issue of slopes. 358 mesh panels are very rigid, so they don’t do well on sloped sites. You would need to cut the panels to follow slopes and use techniques like stepping to get the fence to follow a gradient.
358 mesh fence systems are designed to be security fences, so you will struggle to find them in anything under 3m height, unless you have them specially made or cut to size.
They can go up to 2.4m or 8’, 3m or 10’ or 3.6m or 12’ high in most standard sizes, and they can be specially made in other heights for special systems like bowed fences.
Usually, the width of the panel is designed for post spacing of 2.4m / 8’ or 3m / 10’, but again, there might be other options.
Hopefully, you know a little more about 358 fences now, but there’s one more thing you should know.
This is a highly technical fence system and should not be installed by any contractors who don’t specialize in this type of system. It requires a high level of precision, and in the hands of the untrained, it can be very difficult to get prison mesh fencing right.
So, make sure you not only choose the right specification, but also the right contractor for the job.
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