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This introduction to wire balustrade is for those who are looking for guidance on which wire balustrade systems and options are best for their specific requirements.
The information provided here is general in nature and does not constitute legal advice. While all information is provided with respect to Australian laws and building regulations, as always you may want to seek professional advice from a licenced tradesman, surveyor or building regulator for your specific situation.
Here are some frequently asked questions which we’ll answer later:
When considering using wire balustrading, you should first think about the rules and regulations that pertain to barriers and handrails in Australia.
Thinking safety first will help prevent injury of your family, friends and loved ones.
Always stick to the Building Code of Australia (BCA) guidelines and gain approval from your local council to ensure your wire balustrade is legal and safe. You can download the National Construction Code (NCC) 2016 which is still current as of February 2019, for free. An updated version of the NCC will be released in 2019.
See NCC 2016 Volume One Amendment 1 for Commercial or Government Barriers and Handrail
See NCC 2016 Volume Two for Residential Barriers and Handrail, in particular, section 3.9.2
Below is an excerpt from section 126.96.36.199 which details the required tension for stainless steel wires, when used for a barrier (wire balustrade).
Most residential wire balustrades use 3.2mm diameter wire rope – usually either 1x19 or 7x7 constructions. The below 3.0mm diameter figures can be substituted for 3.2mm (as per Note. 3).
Guidelines on acceptable wire tension for wire balustrade. The above table is from NCC 2016 Volume 2 Section 188.8.131.52.
The above table shows the maximum permissible deflection for stainless wire rope
Barrier construction for stairs/angles
Different wire balustrade systems will suit different situations.
Initial considerations are:
Other factors include:
Entry level wire balustrade systems are versatile and be used for both flat and stair areas as well as for timber or metal posts. They can also be installed with low cost mechanical tools. Bear in mind they're more time consuming and tricky to install and also more bulky in appearance. If price is your only priority then these are your best bet.
Neat, slimline and more aesthetically pleasing systems are typically easier to install. With these systems you’ll maximise your views and keep your wires barely seen. They require strong hydraulic crimping tools, but don’t worry, they’re available for rent or purchase. Alternately, your wires can be professionally prepared by our team (called Factory Swaging) for you or a trade professional to simply and easily install... so you can get back your weekend and spend your time on something you’d rather be doing!
If you’re having trouble deciding or you need some expert advice, just send us an email (click on the Support button at the bottom right) with your plans and ideas – we’re experts and here to help.
Mechanical swaging is the method of using a hand operated swaging/crimping tool, to loop stainless steel wire (usually 7x7 or 7x19 constructions) around a thimble and secure the wire together to forma loop using a copper swage fitting.
A 'mechanically swaged' copper swage ferrule with a thimble and wire rope
Hydraulic swaging is the method of securing a stainless wire to a stainless swage fitting, which can then be secured to a post or other fixing point. 1x19 wire rope requires this swaging method as it is too stiff to loop around a thimble.
The purpose of wire balustrade is first and foremost to provide a barrier to prevent injury or possibly death. With this in mind, you do not want to allow a 125mm sphere (ie. a baby’s head) to pass between your wire runs. The easiest way to achieve this is to keep your wire spacing close together, keep tension on the wire and to have short intermediate post spacings.
Conversely the further apart the wires are spaced, the more tension you'll require to stop it spreading apart and you'll need closer intermediate post spacing.
As per the NCC, the minimum handrail height is 1 metre above the trafficable surface.
Remember earlier we talked about the importance of stopping the wire from being spread apart to allow a 125mm sphere (baby's head) through?
One of the ways to do this is to increase the wire tension.
Also be aware, the further apart you have your intermediate post spacings, the more tension you are going to require on your wire. as intermediate post spans increase, the wires can be more easily spread apart. This is something that you want to avoid it at all costs.
What do I need to install wire balustrade?
1. The first thing you need to decide on is which wire balustrade kit (system) you like/want. You can check them out on our wire balustrade kits page. The ones with the most reviews are our best sellers.
2. Then you need to work out how many metres of balustrade wire you need (measure the post-to-post measurement for each section you want to run wire between. Then multiply the measurement by the number of wires you want to run.) You can then choose which balustrade wire type and reel sizes here. You can learn about the different wire types here.
3. Then you'll need to select the appropriate crimping/swaging tool (hydraulic or mechanical). For a description on these, see above.
4. Then you'll need to choose the appropriate installation tools including wire cutters, tensioning spanners and drill bits.
How far apart do my posts need to be?
For 3.2mm wire, the sweet spot for tension is between 1000mm to 1500mm intermediate post spacing. Any more than this and it becomes very difficult to tension the wire enough to meet regulation. And too much less than this, although perfectly OK, may start to increate costs as posts are added and visual bulk is increased.
How may runs of wire do I need?
Using 3.2mm wire rope (either 7x7 or 1x19 typically), usually 80mm wire spacing. You can see the NCC wire spacing table above.
For most standard applications, where a 40mm thick (or more) handrail is 1000mm above the trafficable surface, then 11 runs of wire spaced at 80mm are required.
If the NCC regulations don’t apply, then you can use whatever number of wires you prefer.
What spacing do the wires need to be at?
What is swaging anyway ... and how do you pronounce it!?
Swaging, pronounced ‘sway-jing’, also known as crimping is the process of securing fittings to wire rope, so that they become a single assembly. This allows you to fix the end of your wire rope run to a post or other fixing point. Swaging requires specialist tools which are usually either mechanical or hydraulic. You can either do this yourself by buying or renting the appropriate tools, have a tradesman complete it for you or you can opt to have it completed in the factory, such as with our factory hydraulic swaging service.
What is the best system to use for timber posts?
The answer to this question is: it depends! Generally the best system to use is a balance between your budget, aesthetics and ease of installation.
You can browse our timber post systems here.
What is the best system to use for metal posts?
As with the timber post systems, the answer is: it depends, based upon your budget, aesthetics and ease of installation.
You can browse our metal posts systems here.
What wire type do I need? What’s better?
There are three main constructions of marine grade stainless wire rope commonly used for wire balustrading: 7x7, 1x19 and 7x19.
7x7 wire rope is a construction of 7 sets of 7 wires. It is flexible and can loop around thimbles, allowing it to be easily crimped with metal copper swage fittings. 3.2mm wire 7x7 has a tensile strength around 6.2kN, which amounts to over 600KG of break load – which is strong! Common 7x7 uses include espalier and trellis systems, wire rope slings, catenary wire and wire balustrading.
1x19 wire rope construction is the strongest construction, made from 19 individual strands twisted in a helical fashion. It is the heaviest, least flexible wire with the highest break load of over 8kN or 800KGs. It also has the least stretch over the same tension compared with the other constructions. It requires stainless swage fittings such as bottlescrews, fork terminals and swage stud terminals to connect the wire to the fixing point (ie. post). These fittings require hydraulic swaging. There is physically more stainless steel metal in 1x19 construction, so don’t be fooled by just comparing 3.2mm diameter constructions by price. Common 1x19 applications include architectural projects, Melbournes tram stop balustrades (5mm) and marine yacht stays and wire balustrading.
7x19 wire rope has 7 sets of 19 wires. It is the most flexible and can also loop around thimbles allowing it to be easily crimped with copper swage fittings. It is less common for wire balustrading. Common 7x19 applications include catenary wire, shop window light boxes, gym equipment cables and bore water pump securing.
What’s the cheapest and easiest system?
The cheapest is never the easiest. Conversely the easiest is never the cheapest.
What’s the neatest system?
Wire balustrade systems that utilise hydraulic crimping are by far the most slimline. ProRig has a number of original design systems which we stock and sell, which focus on aesthetics above all else; minimal bulk and smaller fittings with concealed fixing points.
How long can my span be?
In a nutshell, for 3.2mm wire most systems can handle up to a 7-10 metre span. The reason for this is it becomes more difficult to crank up the tension for a longer run. For spans longer than these, you can choose a different but similar kit, with a second tensioner (bottlescrew or turnbuckle). Otherwise, you may want to split the run into two runs.
Can I go around corners with the wire?
Usually not. Changing direction decreases your ability to tension the wire. The more acute the direction change, the harder it will be to maintain wire tension. 1x19 wire rope is not flexible and will struggle to change direction. Always remember, to meet NCC regulations you need to stop the wire from spreading apart to allow a 125mm sphere to pass through. Any change in wire direction will facilitate exactly that. Furthermore, the wire will chafe and put undue stress on your posts. We simply can't recommend it.
Secondly, trying to change direction whilst passing through a post can prove problematic. Not only will you need to potentially drill holes at different angles, you’ll also need to ensure you put grommets on the runs to stop the wire from chaffing on the exit hole.
How much wire tension do I need ... and how do I know if I have enough?
Enough to prevent a 125mm sphere from being pushed between the wires. But be careful not to over-tension the wire as it will place stress on the fittings and your posts. The amount the wire moves when a force is applied to it is called deflection. Furthermore, the NCC stipulates the maximum permissible deflection for stainless steel wires, as illustrated by table 184.108.40.206 above. You'll see that some intermediate post spans have an 'x' - indicating that these run lengths would exceed the safe load of the wire.
You can measure wire tension a number of ways. You can suspend a 2kg mass at the centre-most point of a wire span and measure the deflection (measured in mm). You can also use a wire balustrade tension gauge.