In a nutshell the performance requirements that NCC stipulate include:
- Where people could fall 1m or more, a barrier must be provided which must be continuous and of a height to protect people accidentally falling
- The balustrade must be constructed to prevent people from falling through the barrier
- The balustrade must be capable of restricting the passage of children
- The balustrade must be of suitable strength to withstand foreseeable impact of people and static pressure pressing against it So, bearing that in mind, let’s think about all of the imposed actions and load of the balustrade.
- Min 1000mm high (865mm on stairs)
- Max 125mm sphere through gap / opening
- For floors more than 4m above the surface beneath, elements between 150mm & 760mm must not facilitate climbing
- Glazing used in balustrades must comply with AS1288
Balustrade Glass Selection
Various Types of glass are approved for balustrade installations as per AS1288 which can include but not limited to -:
Heat Soaked Toughened (Cheapest Option)
This glass is non-structural and therefore requires balustrade stanchions and a connection top rail to the glass panels.
There is a minimal risk of this glass exploding due to the possibility of nickel sulphide inclusion or impact
Laminated Glass with PVB Interlayer
This glass is non-structural and therefore requires Balustrade stanchions and connecting top rail to the glass panels.
There is a minimal risk of breakage due to the possibility of nickel sulphide inclusion or breakage.
Because a laminate has been selected the broken panel will stay in place until a replacement panel can be sourced.
The broken panel is not structural.
A metal capping is recommended to be fitted to the top of the glass panels to reduce the risk of De-Lamination.
Laminate Glass with SGP Interlayer (The Most Expensive Option) Structural
This glass is structural and therefore does not require stanchions or a connecting top rail to the glass panels.
Naturally SGP Interlayer Glazing can also be installed with stanchions and connecting top rail should be the design intent.
Should this glazing be affected by nickle sulphide inclusion or breakage the glass panel will remain structural sound because of the SGP interlayer unit a replacement panel is sourced.
If SGP Glass is installed without stanchions or a connecting top rail to the glass panels then the glass is the structural component.
In this instance the QBCC require installation by a licenced glazier.
The Standard states that Grade A Safety Glass shall be used (Toughened or Laminated) and that the Min Thickness of glass derived from wind loads but is typically 10mm for infill panels and 15mm for frameless.
The glass treatments that we should consider: – Heat Strengthened, and Tempered (Toughened)
DID YOU KNOW
All Balustrade regardless of the design selected have to have structural engineers Form 15-Design & Form 16 Inspection.
The Form 15 (Design) has to calculate the structural integrity of the design and the associated wind pressures exerted on the glass panels.
These certifications are not generic and are required for all individual projects.
Existing Balustrades and Repairs
Repairs to existing balustrades can be performed and the balustrades are compliant with the standard of that time.
If the existing balustrades are removed and new balustrades are installed, then these balustrades need to comply with the current standards AS 1170 D5-16 of today. Along with structural engineer’s design and certification.
What are the current BCA Requirements for balustrades?
The current BCA requirements are that a balcony balustrade have the following attributes: –
- The top of the railing must be least 1 metre (1000mm) from the ground.
- Any opening must not allow a 125mm sphere (i.e. child’s head) to pass through. So, the vertical components must not be more than 125mm apart.
- The gap between the balcony surface to the bottom rail must be no more than 100mm.
- For balconies with a fall height of more than 4m there must not be any horizontal or near horizontal elements between 150mm and 760mm above the floor that facilitate climbing.