As recent storms have shown, sometimes NZ gets windy… very windy. It’s at this point that the wind loading performance of balustrades, or louvre roofs comes to the forefront of minds, especially if it was overlooked as is often the case with louvre roofs.
When designing systems Juralco aims for compliance across most of NZ. Specifications for wind loads are based on either wind zones (Low, Medium, High, Very High, Extra High) or a definable wind pressure such as 1.5Kpa (two storey buildings in wind zones up to Very High,) or 2Kpa (generally accepted as two storey buildings even in Extra High wind zones).
Compliance in the majority of these zones is usually easy, cross reference the wind zone for a Bask Louvre Roof for instance, to find out the maximum bay size that can be achieved. For balustrades, ensure the wind pressure is not outside one of the definable cut offs (1.5Kpa or 2Kpa), select the fixing method, the balustrade height required and the span between fixing centres becomes obvious.
So what happens when the requirements exceed the standard cut offs? Are there any options? In louvre roofs increasing the size and getting engineering approval (without structural changes) is unlikely, but connecting multiple bays together allows for larger roof areas. As a general rule, any increase in wind zone equates to a decrease in the maximum bay size allowed.
In balustrades the clamp or post centres may be brought in to achieve compliance, so check the manual, or if in doubt contact Juralco.
Juralco balustrades all comply up to Very High wind zones residentially, but in Extra High wind zones choices are more limited. Post systems are still compliant, but frameless glass systems are more challenging, as the pressure on holes cut in the glass for fixings tends to be the main mode of failure. However, Juralco’s Edgetec Infinity frameless channel balustrade is suitable, as glass is fixed by internal clamps (not requiring cut holes), which can be spanned for performance in different wind zones, without affecting the overall aesthetics.