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The Logistics Of Structural Glazing

Structural glazing may be an elegant, effortless architectural focal point in-situ – but what does it take to design, produce, and install these kinds of installations? In this article, we examine the logistics of glazing.

Date

23 Jun 2022

By

Simon McAuliffe

Large glazed extension on the back of a Victorian terraced house

Most people would agree that structural glazing, when used correctly, is an aesthetic spectacle. At the height of a warm summer’s day, your space is suffused with a warm glow. Meanwhile, there’s something particularly striking about looking at a fully-lit glass room at night, it emanates a warming, welcoming radiance that inexorably draws you in.

While that’s all fine and good, the actual business of manufacturing, transporting and installing glass can be somewhat less romantic. From 20m panels to intricate, delicate invisible corners, in this article, we’re going to take a look at how an architect’s vision becomes reality.

From supplier to site

The first hurdle when thinking about challenging structural glazing projects is getting the glass from our suppliers to site. Over the years, continental Europe has become the glass manufacturing centre of the world, with some of the most specialist glass coming out of Sedak in Germany, who have supplied glass at a whopping 3.6m by 20m (72m² of glass) in a single panel. The only drawback with getting glass from Europe is the logistical challenge of getting such a large, heavy item across the channel and onto our sites.

 

Luckily, we’ve been in the business over 36 years and over that time, we’ve developed partnerships with all sorts of specialist contractors, from freight companies to specialist crane hire companies. The first thing to note about a panel at 3.6m by 20m is that it’s 20m long (obviously enough). This means that a normal truck simply won’t cut it, and sedak have actually worked alongside their transport suppliers to develop a 23m long truck with a steerable rear axle, allowing this behemoth to negotiate even the tightest turns, and to navigate the rural country lanes where the panel will finally be installed.

A man sitting at an office desk working at a computer

On-site challenges

Even once the glass is on site, there can be difficulties manoeuvring large glass panels. On some sites, the client or builder has had to rethink the landscaping, for instance, moving or removing trees that would otherwise get damaged (or damage our glass). Lifting the glass is another consideration – when you’ve got a panel that weighs in at over 3.5 tonnes, such as the one on the gymnasium at The Newt in Somerset, you need specialist lifting equipment. In this case, we used a crane that could lift up to 130 tonnes and had to be supported on a timber base to stop it sinking into the ground. The crane was attached to a rig containing 20 vacuum suckers to spread the load of the glass and ensure no part of the panel was under more pressure than the others, keeping the whole thing in one piece.

19m panel of glass on a natural stone facade looking out over a herb garden
Cinema foyer with cafe seating and large glass facade overlooking Leicester Square

Considerations during the design process

When designing a glass structure, it’s vital to get the people actually fitting the glass involved early on, as well as project managers, as they will be coordinating the transportation and installation of the glass. Designers, installers and project managers should collaborate throughout the drawing process to design a structure that’s not only aesthetically pleasing, but also practical and (relatively) easy to install.

Large glazed box extension with Sky-Frame sliding doors on the rear of a mock-Tudor house
Two-storey glass extension with framed glass doors and large fruit tree in front of the glass

Case in point: The Newt in Somerset

At The Newt in Somerset, there are a number of spectacular glazing installations, from the largest single panel of glass in Europe to an 18m² pitched roof supported on a glass façade, but one of the most challenging installations looks comparatively unassuming to the untrained eye.

The Beezantium features a cantilevered, frameless oriel window, so far, so simple. However, the glass on the front, top and sides of the projecting box weigh almost 2 tonnes (most of this is the front panel, weighing in at a hefty 1.1 tonnes). When this rests on the floor, which itself weighs a not insubstantial 675kg, the floor will naturally tend to slope down under the enormous weight. To compensate, our fitter on site, one of the most experienced here at Cantifix, suggested a system of screws that could be adjusted as the front, top and sides pressed down on the floor to ensure the floor finally comes to rest at 0°. The system is cleverly concealed with back-painted glass, giving a clean, minimal look to what is actually a fairly complex construction.

The canopy between the cider press and the cider house was also deceptively tricky to install. This time, it wasn’t the glass that proved tricky, but the “framework”. On one edge, the canopy is fixed into the wall of the cider house, but on the other, it hangs from an oak beam. When fixing through glass, the holes in the glass need to be pre-cut by the glass supplier, so the fixings had to go through the oak beam at precise points along it, otherwise the holes in the glass wouldn’t line up. To save our installers time measuring up on site (and avoid the need for any guesswork), our designers created a template for drilling through the oak beams to ensure the holes in the beam and glass panels would line up, ensuring an easy, pain-free installation and a perfectly aligned finish.

Frameless glass oriel window overlooking a large pond
Woman standing in front of a frameless glass window with honey-comb style artwork in the foreground

Final thoughts

When dealing with large, or challenging structural glass, in order to create a beautifully minimal, fuss-free finished product, there’s a whole spectrum of challenges that have to be overcome from production to fitting the glass. The end results are often so breathtaking in their simplicity that it’s difficult to envisage many of these hurdles. Luckily, by working with a specialist like Cantifix, you have access to knowledge, expertise and professional relationships that ensure you won’t have to worry about any of them.