Kawneer AA201 unitised curtain walling system
Capella Building, Atlantic Quay, Glasgow
Bruce Kennedy, director, BDP
The £26m Capella tower is the tallest of six office buildings designed by BDP for Glasgow’s 38,000m2 mixed-use Atlantic Quay development, in the former tobacco warehouse district. Two cladding systems were specified for the facades: 700m2 of Kawneer’s stick curtain walling at ground level and on the 10th floor; and 3,600m2 of AA201 pre-glazed unitised cladding for the rest of the exterior. There are roughly 800 unitised panels and the average panel size is 3.9m high by 1.5m wide.
We were initially reluctant to select a unitised system, but our curtain walling specialist Charles Henshaw & Son recommended it and once we looked in depth at the job and the specific site conditions, we realised it was both practical and very cost effective.
At ground level, there are suspended concrete slabs over basement car parking on three sides, which would not take the load of scaffolding required to construct a traditional stick curtain walling system. But the pre-glazed AA201 unitised panels can be installed from within the building without the need for scaffolding.
The system offered programme advantages for main contractor Balfour Beatty, as it could glaze the building one floor at a time, then progress with M&E work inside without waiting until the building was fully wind and water-tight.
Aesthetically, we wanted to maximise the glazed area and AA201 has very slender vertical mullions, which creates very good sight lines. It is also a frameless system so there are no external framing members or face caps, it’s simply glass-to-glass joints with a silicone seal.
Before we ordered the system, Kawneer even flew the project team and client Wilson Bowden to its factory in Toronto to inspect the system and took us on site to interview a contractor currently installing it on a building.
Tips of the Trade
How to select cladding lifting gear
01 Check what plant is already available on site
The cladding lifter you choose will depend on whether you’re working with a forklift, telehandler or mini-crane. Generally, cladding lifters are either forklift attachments or below-the-hook lifters.
02 Ensure you know every detail of the cladding
When lifting cladding, it’s not simply a case of knowing the weight. You will need to factor in the profile, surface texture, thickness, length, width and weight of the cladding units you intend to lift.
03 What kind of lift is it?
The cladding lifter you require will depend on the sort of lift it is, ie whether it is a vertical, horizontal, wall installation or roof installation. Different lifters have differing features including tilt and rotation for a variety of lift types.
04 How are the cladding panels packed?
This element could easily be overlooked but impacts upon whether the cladding lifter you use needs to be able to rotate the panels on site, or whether they need to be rotated and repacked at the cladding factory, which would have a cost implication.
05 Always be prepared
As with any lift, there’s a lot that goes into ensuring it is carried out safely. Make sure you’ve accounted for — in costs as well as time — the necessary training, method statements, lift plans, risk assessments, and operators before you get to site.
Chris Lord is operations director at GGR Group, a supplier of lifting solutions. www.ggrcladding.com
Product news
The PassivHaus Institute has certified the first ever aluminium transoms and mullions for use in curtain walling, according to maker Schüco. Its FW50+.SI and FW60+.SI profiles have sufficient levels of thermal insulation to get the thumbs up from the organisation. To meet PassivHaus standards, the total energy demand for space heating and cooling in a building must be less than 15 kWh/m2/pa of floor area and the total primary energy use for all appliances, domestic hot water and space heating and cooling, must be less than 120kWh/m2/pa.
Architectural aluminium glazing specialist, Technal, has launched a low-rise glazing system with enhanced security and high thermal efficiency as standard. The Modal system is ideal for schools, hospitals, community centres and other public buildings. The system’s security features include a specially-designed screw for the integral opening vent that prevents removal of the bead and glass from the outside. Modal is the first low-rise facade system to be tested to BS7950, the specification for enhanced security performance.
Alcoa Architectural Products has launched a range of aluminium composite panels in 43 different natural designs. Reynobond is divided into two ranges. The first, “wood design”, features 22 different wood patterns including colonial red, walnut brown and dark oak. The “natural finish” range includes 21 colours from four granites through to sandstone, zinc and copper. The 4mm panels have been designed to be weatherproof, cost-effective and easy to use as well as more versatile than the materials they simulate.
