Below is an article on wire rope balustrades to refresh the methods of installing them, display some pictures and highlight some pros and cons of this type of balustrade.
Wire rope balustrades are normally installed when one wants to avoid limiting the view as much as possible whilst still providing a barrier at the end of a deck. As opposed to solid timber balustrades which obstruct the view when in a seated position. A wire rope balustrade limits this as the cables are only 4mm thick.
On a standard 1m high compliant balustrade one would use 8 strands resulting in 9 gaps of 107mm each after taking into account that the capping is 30mm thick. Although the wire rope is tensioned on either end it is not tensioned to guitar string tension and can therefore be pulled open to create a bigger opening than 107mm. Care should therefore be taken when installing these wire rope balustrades if the property owner has small kids. They are not the safest and the height of the deck off the ground should be taken into account when choosing this style of balustrade.
As mentioned above the wire rope has a 4mm diameter. It consists of 19 smaller strands making up one larger strand (1 x19). The other type of wire rope is a 5mm wire rope. This is a 7 x 19. So it has 7 x 19 strands that make one 5mm strand. At The Wood Joint we use only the 4mm (1 x 19) wire rope as this is marine grade stainless steel and won’t tarnish as easily as the 5mm wire rope.
The 4mm rope doesn’t bend as easily as the 5mm rope so it cannot be used in conjunction with turn buckles where the rope needs to bend around the buckle 180º. Instead we make use of a swage and button head system where the wire rope is crimped into a swage on one end and a button head, which is sunk into the timber upright, on the other end. They are much neater than turn buckles but it does result in terminating the strands at a 90º corner and starting a new strand for the next run. As such, posts need to be doubled up so that a new button head can be installed where a swage terminates on the previous run. The end result is a slightly more expensive balustrade but one that won’t tarnish as easily and one that has a much neater appearance.
Care must be taken to cut the wire rope at the right length so as to have enough rope to insert it into the swage but not too much so that it can’t be tensioned properly. Once it is cut and crimped it can’t be re-cut or “uncrimped”.
The swage and button heads should be crimped towards the beginning and crimped twice to avoid failure later on. They can be finished off neatly with a stainless steel dome nut.
We are both suppliers and installers of wire rope balustrades. We own a crimping tool designed for 4mm wire rope which is also available for hire. Call us on 031 – 762 1795 or use the contact us form below for pricing and availability.