Is your balustrade compliant?

What must you consider to make your balustrade compliant.

stairs 

When is a barrier required?

First things first, let’s make sure we have our terms right. A balustrade is a row of balusters or other type of infill, and the balusters are close vertical members that act as infill. Other infill options can be glass, wire, mesh, metals and timber.  A ‘balustrade’ is the commonly used term for a barrier. A barrier is any building element intended to prevent a person from falling and to retain, stop or guide a person. They are required for any fall greater than one metre. Swimming pool fences, however, are a different kettle of fish and fall under NZS 8500.

 fall off balcony

What must it do?

That out of the way, how does it need to perform? Putting it plainly, it needs to be able to stop people from falling. Barriers must be continuous for the full extent of a potential fall. They must be high enough to minimise the possibility of a person falling over them and sturdy enough to prevent a person falling through them.

The infill must prevent a person from falling through the barrier and restrict a child from climbing on or over it. In buildings likely to be frequented by young children, the barriers must offer no easy or obvious means of climbing. They must provide no toe-holds between 150mm and 760mm above the finished floor level. For barriers with a ledge between 150mm and 760mm above floor level, the ledge depth must be 15mm or less unless it is sloped at 60 degrees below the horizontal towards the occupant. This is to stop little toes getting a foothold and climbing up. Furthermore, the openings anywhere in the barrier (except the triangular opening formed by the riser, tread, and bottom of the rail) must be of such size that a 100mm diameter sphere cannot pass through them

 glass square

How strong must it be?

The next import factor is loading, i.e. how much force can it take. For outside applications, this needs to factor in wind loading as well as the forces of people potentially leaning against them. These calculations need to factor in handrails if they have them, as these can drastically change forces applied to the barrier. The required loads will also vary depending on the occupancy of the building.  Applications that may be used with large numbers of people will need to bear the load of large crowds applying pressure on them.

 semi frameless balustrade

How high should it be?

This can vary slightly depending on the application, but as a general guide, stairs and ramps must be 900mm from the finished floor and measured from the pitch line or stair nosing. Mezzanines and balconies within residential applications should be 1000mm, while in public and shared common areas - 1100mm.  Of course, there are always exceptions to the rule - they only need to be 800mm in front of seated areas, such as cinemas and theatres.

 Monkey toe glass balustrade frameless 2

What is changing?

Auckland Council is introducing changes to frameless glass balustrades, requiring them to have a top edge. Heat toughened glass can shatter if hit with enough force on the edge. To avoid the potential of this happening, regulators are requiring a handrail or top edge on glass balustrades. While there have been no recorded events of people harmed from this, Australia has regulated this, and New Zealand is likely to follow. This can be overcome however with new technology in laminated glass such as sentryglas plus.

 

 balustrade detail

Fixings

The fixings securing the barrier system to the building must have at least equivalent strength to that of the rest of the barrier system. This also applies to all the components of the balustrade.

This is to ensure that under extreme loading the barrier will indicate failure by deflection and distortion rather than by rupture and sudden collapse, as would be brought on by failure of a fixing or connection.

Consideration must be given to the substrate into which the fixing is being placed. Substrate and fixing all affect the capacity of the connection. When it is not possible to calculate the capacity of the fixing into a substrate with reasonable accuracy, then load testing should be carried out. 

 glass balustrade building

How long should it last?

Balustrades and barriers are part of the supporting structure, and as such, need to last the lifetime of the building - 50 years. This is based on the assumption that the building element (post/rail) is either difficult to access and replace, or that failure would go undetected in both normal use and maintenance. However, if it can be shown that the post, handrail and fixings can be accessed and replaced without difficulty and that failure would not go undetected, then it would be acceptable to reduce the durability requirements for these elements to 15 years

 call agent

Where can I learn more?

Most of these details will need to be worked out by your architect and engineer. Below is a more detailed paper by the Department of Building and Housing. At Monkey Toe, our engineers will also help with a project to ensure it is fully compliant. Drop us a line if you would like a quote or assistance or take a look at our PRODUCTS page where you can find information on our balustrades.

 

Download guidance on Barrier Design - Department of Building & Housing

 

 

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