Kalzip helps the RAF go bold in the cold

Kalzip’s “consistently high quality technical advice” and product “flexibility” have helped Feilden Clegg Bradley Architects stun visitors to the world’s first permanent exhibition on cold war aviation and win a RIBA (West Midlands) Award 2007 in the process.
The new £11 million National Cold War Exhibition at RAF Museum Cosford in Shropshire uses 10,000 m² of Kalzip’s aluminium standing seam system to clad the curvilinear roof and sections of the elevations. But that is putting it simply.
For the building comprises two triangular volumes that rise to 30 metres, creating a 130 metre-long fault line along their adjoining edges. These two opposing volumes provide a physical representation of the two forces locked in the cold war. The triangular volumes gracefully twist along their length, tempering the huge volume of the building.
The designers have more than met the brief for a landmark building that would raise the museum’s profile and house its collection of rare and unique aircraft with wingspans stretching up to 50 metres.
The smooth lines of the aluminium standing seam roof dominate the sculptural form of the building exterior that also features exposed concrete, block work walls and black timber joinery. The palette of materials was chosen to reflect a simple and strong statement through a combination of large enclosure, dramatic gesture and appropriate technology to produce an environmentally and sustainable solution.
The 6,200 m² display hall, in which the aircraft are suspended from the central spine, is humidity controlled to preserve the airframes, through controlled natural ventilation, low level conservation heating, exposed thermal mass and a heavily insulated, vapour controlled roof. This solution was adopted as energy efficient and cost effective when compared against energy intensive air conditioning.
The roof system – standard Kalzip stucco embossed 65/400 standing seam on a structural metal deck – had to follow the ever changing pitch of the structural steel members which swing out from the vertical spine wall to 30º angles at the other ends in shapes technically described as hyperbolic paraboloids.
These shapes became extremely familiar to the roofing contractors, Kalzip approved Teamkal members WWR (UK), who had to train their workforce to abseil for the five months of the installation. The spine walls were clad from mast climbers.
WWR was involved in the 18 month roofing project from the design stage and this included assembling a full size, nine metre bay mock up on the RAF base.
Sales director Stephen Walker said: “Kalzip was really the only material that would achieve the ever changing pitch without crimping along the axis. Standard Kalzip sheets were twisted along their length to achieve the specific requirements of the architects.”
Sam Tyler of Feilden Clegg Bradley added: “Kalzip standing seam plays a critical role in the aesthetic of the building. It clads the greatest part of the roof and elevations which define the curvilinear form of the building.
“Kalzip provided consistently high quality technical advice that assisted the design team in progressing the project. The aluminium standing seam provided the flexibility we required to achieve the curvature of the building using an off the shelf product.
“The setting out of the Kalzip defined the size and requirements of the custom flashings throughout the project which were used to provide clean interfaces with glazed and gable end fabric walls.

Email: tracy@tlcpr.co.uk