Having covered stanchions and handrails in Parts 1 & 2 of Neaco’s Balustrade Design Guide, Part 3 focuses on balustrade infills. This element offers the most variety of choice in terms of aesthetics. Each option has its own attributes and suitability for certain environments. Responsibility for compliance to regulations lies with the architect, so it’s important to check that the manufacturer’s products are compliant and ensure that the specification meets all relevant standards.
Rails are popular balustrade infills for many buildings and they offer the benefits of traditional styling, hard-wearing performance and high visual contrast in cases where this is required (extra contrast can be achieved with powder coated colours and finishes). They can be installed horizontally or vertically and the number of rails can vary according to preference. However, buildings likely to be used by children under 5 years of age have a requirement that the balustrade should not trap the child. To satisfy this requirement it should be impossible to pass a 100mm diameter sphere between the infill rails. We recommend that vertical rails are installed at 100mm centres. It is important to consider ‘climbability’ when applying horizontal rails.
2. Glass panels
Two types of safety glass can be used for balustrade infills: toughened glass and laminated glass. Toughened glass is heat soaked and ‘quenched’ (rapidly cooled) to create a strong outer layer and lock tension inside the core.
Laminated glass comprises two glass panels with a stabilising insert between them to prevent shattering under extreme force. Laminated glass can comprise various combinations: either two float panels, two toughened panels or a combination of both. For the glass to be regarded as safe it must pass an impact test. You can find out more about this here. Make sure your manufacturer conducts recognised glass safety impact tests on it glass balustrade as a matter of policy.
There are a number of ways to secure glass infills:
- Panels held in place by clips attached to stanchions – either offset or in-line with the stanchions
- Panels secured between a channel in the top rail and a channel the floor (not suitable for raked installations)
- Panels held in place by a side fixing to a vertical surface (applies to stair and mezzanine floor installations)
3. Mesh & perforated panels
Mesh infill panels are often chosen for projects which required a more traditional aesthetic. The major benefit of perf mesh is that it is a low-maintenance option that will not require the regular cleaning that glass can be subject to in certain environments. However, the use of mild steel mesh in external environments can cause the coating to bubble and peel. It is better to use aluminium mesh which can be powder coated for a maintenance-free finish in a range of colours to suit visual requirements.
Perforated panels provide a robust solution for high traffic areas. Their durability and compliance with safety requirements make them especially suitable for schools and other environments occupied by children. The size of the perforations cannot be in the 8mm to 25mm diameter range as this poses a finger trap hazard. Aluminium panels can be powder coated a finish to suit visual requirements.
4. Tension wire
With its contemporary minimalist style and cost-effective use of materials, tension wire is an increasingly popular option for balustrade infills. Wires are typically installed horizontally. In buildings likely to be used by children under 5 years, the spacing between the wire is subject to the same regulations as rails (outlined in section 1). By its very nature, tension wire will not curve, so it is not suitable for curved balustrade applications. It is also worth noting that, in designs where there are many starts and stops (i.e. lots of changes of direction) the cost of the wire specification can increase substantially.