Construction of the Invisio Structural Glass Façade
Our newly renovated architectural glazing showroom included the construction of a bespoke structural glass façade at the front that uses IQ’s in-house developed Invisio Façade system.
This complex and unique glass façade system uses the Invisio thermally broken connections and profiles to create a thermally broken structural glazing system that achieves unparalleled thermal performance levels. The planning, design, manufacturing, and construction of this structural glass façade had many intricate parts, and our team faced many challenges which were overcome with quick and innovative thinking.
Read on for more information about the construction of the Invisio Façade at the new IQ Showroom, based in Amersham just outside of London.
THE CONCEPT
Over the years IQ have designed and installed a variety of bespoke glass facades, and now have our in-house developed structural glazing system, Invisio, which uses thermally broken profiles and connections and tested scenarios to create the ultimate structural glazing system unlike anything seen on the market.
The concept for the new showroom space was to create unique installations that push the boundaries of modern architectural glazing, showing architects and developers what is possible, and the Invisio Façade was no exception.
For the façade, the team brief was designing a frameless structural glass façade with the most minimal design that achieved exceptional performance levels in all areas including being able to withstand high wind loads.
THE PLANNING & DESIGN
The design team for the Invsio Façade consisted of our own in-house designers with the assistance of an external specialist glass façade designer. An architect was also vital to the planning as groundworks were needed, and how the steelwork would be incorporated with the existing building needed careful consideration.
Overall, the planning took between 3 and 4 months and as with any innovative and bespoke glazing installation, there were challenges to be overcome. To create such a large glass façade with minimal to no framing, keeping the visible supports concealed whilst ensuring the façade stays strong and is able to take wind loads of up to 1.4 kN/m2.
Luckily, the IQ team are no stranger to these sorts of challenging projects, which are always welcomed as an opportunity to utilise our expertise to produce innovative ways to achieve all project requirements without having to compromise on a modern and minimal design.
Within this stage, selecting the right type of steel for the supporting steelwork took some time. After deliberating and weighing out the options, bright steel was chosen.
THE MANUFACTURING
As four of the five structural glass panes reach a staggering 6.5m tall, we worked alongside specialist glass suppliers and manufacturers from the continent, Guardian Glass manufactured the glass panes and Q4Glass who used the panes to manufacture insulated structural glass units, to design and manufacture these oversized panes.
This size of glass is something not often seen in the UK as panes manufactured in the UK ten to only reach about 6m. This was no issue for IQ as our strong relationship with suppliers around Europe meant that the 6.5m height could be achieved.
Although the issue of where was solved, this then brought with it the challenge of transporting these massive panes of structural glass overseas to the UK safely. The specialist transport for this included a specific type of lorry and a very good driver.
THE STEELWORK
IQ worked with structural engineers Westshore Engineering for the steelwork for this new part of the building which would house the Invisio Façade. Due to the complexity of the framework, the steel beams had to be delivered to and fabricated on-site.
The welding and bolting were carried out inside of the design centre and then brought outside where they were lifted into place, with some of our installation team placed on cherry pickers used to guide the beams.
The two side elements of the goal post framework were put up first. Then between the new space and the existing building, the wall was removed which left the floor above suspended with no support. Our team worked quickly and efficiently to put up temporary support posts and get the supporting steel transom into place.
With some of the beams reaching almost 13m, naturally, there were many challenges faced. This was an extremely complex installation including unlevel ground due to part of the steelwork being installed outside and some within the building.
To keep a cohesive design across the façade of the whole building, the Invisio Façade and any visible supports needed to be finished in the same colour. This meant specifying a unique finish RAL 9005, also known as Axalta Horizon.
During the painting phase of the steel fabrication, the paint caused some of the longer beams to bow, something which is not uncommon and was resolved quickly by the team to straighten out the beams.
In the end, the fabrication of the steelwork took around a week and thanks to the expertise of IQ’s team the whole installation was done in just two days.
THE GLASS
IQ only used toughened safety glass in our designs and include a low e coating as standard in all insulated glazing solutions.
As these large panes would be difficult to replace if broken, both in terms of cost for ordering and transporting the glass as well as replacing the glass, they were all heat soak tested.
This extra step in the glass manufacturing process reduces the risk of nickel sulphide inclusion breakages significantly from 1m2 in every 10,000m2 to just 1m2 in every 1 million m2, and would always be recommended for glazing solutions like this.
Each section of the glass façade is made with a 10mm and 12mm glass pane, separated by an 18mm argon gas cavity for better thermal performance and to allow to deflection.
The oversized structural glass pane within the façade uses the thermally broken Invisio profiles and connections and structural silicone is used in between the panes.
Structural silicone is ideal for this type of glass façade structural and the neat silicone joins help to maintain the frameless design, allowing in a vast amount of natural light and offering uninterrupted views of the outdoors.
THE CONSTRUCTION
Before the actual façade could be installed a whole new section of the building had to be created. This took about a week and included the groundworks, the steel framework, the roof and bespoke pressings and flashings. Once done, it was time to install the Invisio Façade.
Firstly, the perimeter frames were installed into the primary outer steelwork, utilising the Invisio thermally broken aluminium connections and profiles.
Then the mullions and transoms were installed ready for the glass to be added. The mild bright steel mullions sit just behind the silicone joints between the panes and help to strengthen the overall structure whilst helping to increase the wind loading of the facade and prevent excessive deflection on the 6.5m tall structural glass panes.
Due to the height of the glazing IQ had the order specialist bespoke mullions as the standard sizes would not have sufficed.
The steel transom sits at the bottom of the middle structural glass pane to provide support so the door below could be attached.
In this stage the was another challenge to overcome, similarly to with the steel some of the mullions started to bow, our installation manager easily rectified this by using ratchet strap to attach the steel mullions to the outer primary steelwork.
Now it was time to install these massive structural glass panes. Due to the sheer size and weight of these structural glass panes, a standard Hiab crane was not suitable. Some of the panes weighed up to 1.4 tonnes so we had to hire a specialist Hiab crane that was able to lift up to 2 tonnes.
The glass was all put into the facade within a day. This complex part of the installation, although extremely difficult was no feat for our skilled installation teams.
When installing any bespoke glazing, especially with something on this scale, the glass had to be guided in down to the millimetre, as the way the panes were designed to go in meant being the smallest bit out could prevent other panes from fitting.
Once the actual Invisio Façade system has been installed the external cladding was put over to conceal any supports, connections and profile for a clean and minimal design.
Lastly, the slim framed aluminium pivot door from IQ along with the fixed sidelights were installed. There was a lot of deliberation as to which door to use within with bespoke glass façade, and ultimately a slim framed pivot door that is able to open both ways was selected.
Although a manual pivot door was used for our installation at the showroom, the Invisio Façade system has been designed to allow almost any door system to be incorporated.
In the design and planning for this structural glass façade system, it was vital to have flexibility in design as this allows it to be specified for a wide range of projects.
THE END RESULT
As any architect or main contractor will know, large complex projects rarely go to plan, between delayed lead times and issues that arise and have to be dealt with swiftly, it is part of large scale building projects.
These challenges and delays are not an issue, it’s how they are dealt with that can be a problem. This is why with any type of project like this, which tend to be non-residential projects, it is essential to have the right people on the team.
After the installation, it is clear that the months of planning and the weeks spend working to get the system installed were well worth it.
The glass façade now sits front and centre of the new IQ office and showroom, located in Amersham just outside of London so when clients arrive, straight away they are presented with a frameless glass façade.
This type of specialist glass façade would be ideal for any modern office design, contemporary shopfront or any education building type.
Not forgetting the possible applications for hospitality and leisure projects from hotels, to restaurants, to luxury spas.
Essentially the Invisio Façade can be used for any non-residential projects and is designed and manufactured completely bespoke every time, with the flexile design making it the perfect choice every time.
For more information on the Inviso Facade system, to discuss glazing for your next project or to book a showroom visit, contact the IQ team today.
You can now also download the Invisio CAD details straight to your inbox.
Shannon Normoyle
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