There have been considerable changes around glass balustrades over the recent weeks. Frameless and semi-frameless glass balustrades without a top rail (as they have traditionally been installed) are no longer permitted.
What does this change mean?
The New Zealand Building Code (Acceptable Solutions B1/AS1 section) has recently adopted the revised NZ Glazing Standard NZS 4223.3:2016, effective from the 1st of June 2016.
This change means any new structural glass balustrade will now need an interlinking handrail or one of the following alternative methods to comply with B1/AS1.
Some possible solutions by UNEX:
- Use the Spectra Semi-Frameless Glass Balustrade with Top Rail.
- Select a UNEX Frameless Glass System and use standard monolithic safety toughened glass in conjunction with a UNEX interlinking rail. Common examples include the AZS Side Mounted Channel with ARN Top Rail (30 x 39mm) and the Metropolis AZM Top Mounted Channel.
- Opt for the Vetro Semi-Frameless Glass Balustrade with a UNEX interlinking rail fixed to the side of the post or glazed on top of the glass.
- Select a UNEX frameless glass system such as the AZS Side Mounted Channel, AZM Top Mounted Channel or Arena Points; use Toughened Laminate Glass (such as EVA) and either silicon or interconnecting clamps between each pane of glass. In the event of breakage, these will hold the glass panes in place.
- To achieve the totally frameless look as traditionally installed, use a special glass with a stiff interlayer, such as Sentry Glas. This interlayer is designed to prevent a fall should both glass panes spontaneously break. Use in conjunction with a frameless glass system such as the AZS Side Mounted Channel, AZM Top Mounted Channel or Arena Points. Please note that the cost of this glass system is considerably more expensive than other options.
A few points to mention regarding the interlinking UNEX rail:
- At the ends, it shall be attached to a structural building element such as to the wall or a balustrade post.
- The rail can be either attached on the top edge of glass or using brackets off the side of the glass.
- The interlinking rail must still meet the required serviceable barrier loads (Serviceability Limit State — SLS loads, specified in AS/NZS 1170 B1/VM1) should the pane of glass break.
There is a risk of delamination associated with laminated glass. This needs to be taken into consideration when selecting balustrade styles for external applications.
For further information, please contact the glass manufacturer.