The challenge for many construction companies lies in interpreting the architect’s vision, which, increasingly, includes wide sweeps of uninterrupted glazing. This is increasingly true for both interior, as well as exterior glazing. In atriums, balustrades and entire exterior envelopes, there is an increasing requirement for the appearance of a frame-free glazed area, which the technique of structural bonding is helping to make a reality.
Structural bonding is often used to create areas of glazing which are taller and wider, with a less pronounced, less visible seams between the panels. It is also used to create floating glass structures that hide the structural framework behind the glass panels. As well as the visual aesthetic that this forms, the process of structurally bonding bolted systems to the rear of the glass enables efficient and safer installation for these challenging and imposing projects.
Glass balustrading, for example, can be structurally bonded on to vertical steelwork so that, when viewed from the front, it creates glass screens which appear to be entirely free standing, and the bond eliminates the need for a top or bottom frame. The possibilities are plentiful to choose from, whether the project requires a privacy element to the balustrade, which we can achieve by using screen-printed or sandblasted glass; or perhaps a coloured interlayer from the Vanceva range to match with any corporate colour. If security is a priority, toughened laminated glass could be used, incorporating an SGP interlayer, as in the ESG Secure range.
Glass panels are structurally bonded to the framework using a silicone bonding agent. Using Sikasil SG500 structural silicone, the bonding process is completed in accordance with both ETAG 002 and Sika Ltd guidelines through our contractor, who has been approved by the Sika Bonding of Excellence programme. The process produces a permanent structural bond between a glass panel and its framework, which remains as long-lasting and strong as if we had used a frame and fixings. It is suitable for almost any area and is increasingly popular for bespoke shapes and sizes which do not fit standard frame systems.
Although some glass architectural elements can be bonded on-site, as with the apparently floating balustrades, it is preferable to carry out structural bonding in factory conditions. Pre-bonded projects can then be transported to site as finished components, ready to be installed. This will usually reduce on-site time for the installer, and eliminate a degree of dependence on clement weather conditions. Installing pre-glazed, structurally bonded units can therefore help to reduce labour costs and also minimise the potential for on-site hazards.
Structural bonding is growing in popularity in the private, as well as the public and commercial sectors. The process is particularly useful for creating glass balustrades and walls in internal applications, as it reduces visible seams and maximises clear sightlines, allowing occupants to enjoy both external landscapes and internal views to the floors below or above. Self-builders seem particularly keen on this option for creating balustrades for new mezzanines and internal courtyards, often in adapted former commercial properties. This process is also particularly suitable for features such as Winter Garden glazing, for which demand is increasing, especially for new and refurbished apartments.
In some commercial settings, structural bonding also has an added benefit in terms of clearer sightlines for security purposes. With a reduction in the use of frames, it becomes easier to deploy more effective surveillance in airports, train termini and other public locations, all of which also benefit from enhanced aesthetics. In these settings, we recommend using Secure glass, a specialist toughened laminated product which delivers impressive resistance to deliberate criminal or terrorist attack, as well a standing up extremely well to accidental knocks and normal, if intense, wear and tear.
Structural bonding now allows us to provide solutions for architectural balustrades, partitions, doors and canopies, as well as more structural elements such as floors and bridges, atriums and facades, all without the need for mechanical fixings.
Above all, your glass processor will have a fount of knowledge and expertise about the most suitable approach to using frames, fixings and structural bonding. You should feel free to involve them at the earliest planning stage, in order to ensure that the architect’s vision does indeed become a lasting reality.