Glass Handrails, Cantilevered Glass Balustrades, Safety Glass Balustrades, Glass Glazing Balustrades, Staircase Balustrades
Australian Standards |
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Structural design requirements relating to cantilevered glass balustrades protecting adifference in level of 1 metre or more from ground level : 
"A new design requirement is the need to consider whether a balustrade protects a difference in level less than 1000mm or a difference equal or greater than 1000mm.
Should the balustrade be structural and protecting a difference of 1000mm or greater,
it is now necessary to provide a load-supporting or interlinking handrail. There is no provision in the new codes for balustrading protecting a difference in level equal or greater than 1000mm to be designed without a handrail. This provision requires an interlinking handrail to be used with toughened safety glass, laminated heat strengthened safety glass, or laminated toughened safety glass. An interlinking handrail is connected to adjacent panels of glass, or to the building, where adjacent panels are at least 1000mm wide and the balustrade consists of at least three panels.This requirement means that if one of the glass panels fails, the two remaining panels
and handrail must be capable of resisting the defined loads. The handrail must be designed with this in mind.
Relevant Codes Building Code of Australia BCABritish Standard BS6189 used as a source document for balustrade load table in AS1170.1 and the design philosophy for the requirement of interlinking handrails on glass balustrades. The following design criteria apply to cantilevered glass balustrades 1. The glazing must be designed to act as a balustrade and withstand a lateral load of 0.75 kN/m or 0.6 kN/m in accordance with the requirements of AS1170.1. This load should be applied at a height of 1.0m above the slab (and not at the top edge of the glass screen). |
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2. The glazing must be designed to withstand the relevant wind loading determined in accordance with AS1170.2.
3. The cantilever glass balustrade must be provided with an interlinking handrail. (Refer section 2.9 of HB125-2007 "The glass and glazing handbook", copy attached. 4. This document confirms that an interlinking handrail is required so that if the glass is broken, the handrail will stay inplace. 5. We are of the opinion that the handrail must be located at 1.0m above the finished slab floor surface. Locating the interlinking handrail at the top of a glass panel which is higher than 1m in height dimension will be too high. Excerpt from the relevant British code
BS6399-1:1996 "In design, the horizontal uniformly distributed load line should be considered to act at a height of 1.1m above datum level (Australian case is 1m above the datum level) , irrespective of the actual height of the element. For this purpose the datum level should be taken as the finished level of the actual platform or the pitch line drawn through the stair treads."
Also : "The handrail should be attached to the glass in such a manner that, should the glass fracture, the handrail : a) will remain in position b) will not fail if the design load is applied across the resulting gap. c) Condition b) may be relaxed where the glass pane is an end panel and protects a difference in level of 600mm or less, for example, at the foot of a flight of stairs. In cases where the end pane protects a difference in level of greater than 600mm, there would normally be an adjacent structure to which the handrail could be attached, thus enabling it to meet condition b)". |
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