When it comes to constructing decking, there are a surprising number of regulations that apply. Some of the most vital regulations concern the height of the deck, whether a handrail or barrier is required and if so, how it should be designed. These requirements have been developed specifically to prevent deck-related injuries, especially for decks located high above ground where a fall could cause serious injury or death.
When is a handrail required?
The Building Code of Australia (BCA) advises that a handrail is required where there is the possibility of falling over one metre or more from a floor or building. In other words, a deck less than one metre (1m) above ground is not required to have a handrail, though depending on the height it may still be recommended.
Decks four metres (4m) from the ground or higher need to meet additional design requirements. For these decks, the handrails must not have any climbable elements located between 150mm and 760mm of the floor. This means horizontal balustrades are not allowed to be used at this height, and vertical balustrades should have no footholds.
What are the regulations for a hand rail?
There are a number of spacing regulations that determine what materials you may use to construct a railing and where your railing components need to be placed. The hand rail itself should stand a minimum of one metre from the surface of the deck, with a clearance no more than 125 mm from the surface of the deck and the balustrades should have no spacings greater than 125mm to prevent large objects falling through.
The width of each baluster and railing will need to take these measurements into account. For instance, a railing using stainless steel wire as a balustrade will need more strands to accommodate spacing requirements than balustrades created from tube steel. There are spacing requirements for the maximum span between railing posts as well as for intermediate vertical supports.
There are regulations concerning the capacity for loads on the rail as well. These regulations advise how much weight or strain a railing should be able to bear from reasonable pressure such as people leaning on it or strong winds. The regulations vary according to contributing factors, including the type of dwelling you have, what material your railing is constructed from, and even things like how many bolts you’ve used to secure it.
For more technical specifics on handrail spans and stress requirements, read the Australian Timber Development board's paper on this topic.
What does the future hold?
There are a number of studies which have been done to investigate accidents related to decks and balconies, such as Monash University’s paper 'Slips, Trips and Falls' which may soon be incorporated into the BCA. These requirements are likely to be much more stringent than current regulations, specifically around the “climbable elements” component of the code.
