Guarding is a general term referring to barriers, in and about buildings, including balustrades and full height barriers, which protect people from falling where there are stairs, ramps, floors and balconies. The purpose of certain barriers is also to retain, stop or guide.
In commercial applications, guarding is to be provided where there is a change in level of 380mm or the equivalent of two stair risers. In all buildings, where guarding, in this case glazing, protects a change in level and the glass finishes within 800mm from the finish floor level (FFL), the strength of the glazing must ‘provide containment.
While designing the balustrade, the following factors must be taken into consideration: 
Resistance to Loads
Guarding should be designed to withstand loads imposed in the most extreme circumstances, without deflecting or distorting beyond the permitted limit.
Barriers must withstand the following three design loads:
  • a horizontal uniform load or line load, (kN/m), pressure exerted on a horizontal line 1100mm above finished floor level
  • a uniformly distributed load also known as ‘UDL’, (kN/m 2 ), pressure exerted over the entire panel
  • a point load, (kN), concentrated pressure on the glass
The glass must resist the load without breaking. A free-standing glass barrier must withstand all three loads, whereas in the case of an infill panel barrier, the line load is applied to the handrail.
The barrier must not be penetrated under loading, i.e. it must prevent anyone falling through the barrier.
Wind Loading
External barriers and external full-height glazing should be designed to comply with the standards and withstand the wind loads.
There must be no horizontal elements which would allow the barrier to be climbed.
In areas likely to be used by children, a sphere of 100mm diameter must not be able to pass through the widest gap in the balustrade, allowing for deflection under load. This is also referred to as the ‘Sphere Test’.
General Safety Details of Barriers
The finished barrier should not have any sharp edges or projections that may injure persons or damage clothing.
Fabrication and Installation
Any construction or structure acting as support for the glazing must be of adequate strength and stability to sustain all applied loads safely.
Finished barriers should have no sharp edges or projections that may cause injury.
Once the fitting type and thickness have been decided, various finishes are available to improve the aesthetics of the balustrade ironmongery.
Options such as polyester powder coated, mill-finished, polished, bright polished, shot-peened or machined finished can be specified.
Toughened glass is required for free-standing balustrades. These balustrades should have a continuous handrail fixed to the top edge of the glass.
Laminated glass is suitable for use as an infill panel in protective barriers where the glass is used fully framed.
Toughened glass can be used either fully framed, two edge framed, bolt or clip fixed.
Saint-Gobain provides a range of glasses that can be toughened and laminated, and also add to the aesthetics of the interior and exteriors of a balustrade, while providing safety and security.