Glass Balustrade Maximum Spacing

Glass Balustrades  |  Juliet Balconies  |  Curved Glass Doors  |  Decking  |  Projects  |  Galleries  |  Articles  |  Reviews

This article explains the maximum glass balustrade lengths that can be achieved without posts and the maximum post spacing when required.

Engineering principles

Our glass balustrade system is unique in that we utilise the strength of the handrail profile to achieve the required strength. This enables our system to span wide spans without vertical posts and without cantilevering the glass. The benefits of this come in the form of savings on cost, weight and ease of installation.

In order to explain the engineering principle very briefly we identify these spans as the distance between points where the handrail is fixed, such as for example where he handrail is connected to the wall with a wall fixing. We refer to the place where the handrail is fixed as “a point of support”. Because the glass is bonded to the handrail and bottom rail we also call the corners of the balustrade a point of support. This is only where the length is at least a metre on each side.

bal 1 post spacing

Maximum handrail spans

As explained above the sizes detailed below relate to maximum spans of the systems that can be achieved between “points of support”, without the need to use vertical posts.

On Balcony 1 system (70mm diameter handrail system) the maximum spans that the handrail can have between points of support is 3.3 metres (3300mm).  So if you have a balustrade which is going from wall to wall the maximum span that handrail can have without posts is 3.3 metres. If, for example, you have a balustrade with three sides made using the Balcony 1 system handrail coming out from a wall (fixed to the wall), it can go out 3.3 metres, it can turn 90 degrees another 3.3 metres and again 90 degrees and can return 3.3 metres again being fixed into a wall.  This would be structurally safe as a balustrade with no vertical posts at all.

On our Balcony 2 system (116mm X51mm handrail size) because of the size and shape of the handrail it has a stronger resistance and can achieve a maximum handrail span between points of support which is larger than Balcony 1.  The maximum handrail span on Balcony 2 system is 4.0 metres so you can have a balustrade fixing from wall to wall of 4.0 metres without the need for vertical posts.

Maximum post spacing

Post distances refer to the space between centre of posts. These are determined by the strength of the post and actually come into relevance once the maximum handrail spacings are surpassed.

The maximum post spacing that you can have on a Balcony 1 system is 1.9 metres between centres of posts.  When the maximum allowable span without posts (i.e. 3.3m on Balcony 1 system) is surpassed, vertical posts must be introduced.  If for instance you have a ten metre run, it will need to be divided into a span of maximum 1.9m spans. This will give you a result of more than 5 and of course we have to make sure we don’t surpass the maximum spacing and will need to divide the opening into 6 parts. 1.9m must be the maximum spacing so it would need to be reduced from that.

The maximum post spacing on Balcony 2 is 2.1 metres.  Any opening or any span that is more than the 4.0metres must have posts spaced at maximum 2.1 metres.

handrail spacing post span 1

handrail spacing post span 2

Maximum post spacing Balcony 1 and Balcony 2

Why are post distances not the same as the maximum handrail spacing

The engineering principle of the handrail remains the same, however when you introduce posts then the handrail strength becomes secondary to the post strength. Therefore the limiting factor becomes the posts. There is on occasion a misconception and misunderstanding that can occur when we say that we can span 3.3m with Balcony 1 or 4.0m with Balcony 2.  We mean the maximum span of the handrail where it is supported both ends by way of a wall fixing or corner. It can be misunderstood that we can span this distance between posts but this is not true and this is very important to understand that it’s a maximum spacing between posts of 2.1m on Balcony 2 and 1.9m on Balcony 1, not a maximum spacing of 3.3m or 4.0m between posts.

bal 2 post spacing

The many benefits of the system

The large maximum spans we can have between points of support and the large post spacing we have with our system makes the system very attractive. Usually a posted system will have a post every 1 metre but the Balcony systems obviously can be almost 2 metres with Balcony 1 and just a little over 2 metres with Balcony 2 and with many balconies it can have no posts on large balconies of 3 metres wide replicating the look of structural glass yet not reaching the cost of structural glass.

An additional feature that makes the system so attractive is the fact that is has very clean lines. Between the bottom rail and the top rail we do not need any other fixings so the glass is fixed top and bottom with nothing else showing. Clean vertical glass lines all along.  When there are posts, the posts don’t have anything sticking out of them to hold onto the glass and the system overall gives a very nice feel of clean and smooth lines.