The strength of Metsä Wood’s (formerly Finnforest) Kerto and Glulam has recently been utilised in the eye-catching design of the new Ron Cooke Hub at the University of York – the public face of the campus. Glulam was used for the curved roof beams, which span across the building’s grand hall and Kerto was specified for the roof covering.
The Hub, which has a total floor area of 6300m2 of which the grand hall measures 700m2, is located on the lakeside of the university’s new expansion site, Heslington East. The hub was conceived to provide multiple facilities including offices, a lecture theatre, an immersive sound and visual demonstration space and study pods, all of which cluster around the grand hall for where the exchange of ideas takes place. The hub’s striking design is intended to ensure that the building becomes a landmark over time.
In addition to timber, the roofing system, which was specified by BDP, also incorporates a linear rooflight running the length of the space to light both the deep part of the hall and the main accommodation wing facing into it. In addition tubular steel braces are located within the plane of the roof to reduce the amount of bracing required in the main glazed façade, maximising the sense of openness.
The individually designed wood solution, Glulam, is made from Nordic premium spruce giving it exceptional strength whilst being visually outstanding. The wood solution has a low weight compared to its strength, which makes it easy to assemble and has an R30 fire resistance class; an additional feature of the Glulam is that due to the nature of how it chars it retains its structural integrity longer than other materials making it an ideal choice for buildings of this type. Glulam also provides complete design flexibility. It is available in a large range of standard dimensions, can be manufactured to specific dimensions, cross sections and lengths can be optimised, is easy to combine with other materials and beams can be straight, cumbered or, in the case of this project, curved. For this project’s roof the maximum clear span measured 25m with the largest beam being 1.4m deep.
Kerto Q was used as a panel system in the construction of the roof for the hub in conjunction with the GL32 grade Glulam. The 42mm Kerto Q plates were specified as they created a structural diaphragm action that was a major factor in achieving the stunning finished roof. The Kerto Q plates allow for a great deal of design freedom as it removes the need for additional purlins to support the structure thereby giving an uninterrupted timber finished soffit.
Kerto is a laminated veneer lumber (LVL), produced from 3mm peelings of Finnish Spruce, which delivers exceptional performance. The engineered timber is a strong and dimensionally stable product. Kerto’s strength comes from its homogeneous bonded structure. In addition to being used as a roof covering, the product can also be used in a number of applications such as beams, joists, trusses, frames, floor and wall elements, components of door and vehicle industry, concrete framework and scaffold boards.
Stephen Hill Architect Director at BDP commented, “The Kerto and Glulam beams perform both structurally and aesthetically. They are an integral part of the spirit of the building. The natural warmth of the timber with the gently curving form, low lighting levels and soft acoustic provide a soft and protected environment. As the roof gently dips towards the lake, it shades the space internally from solar gain midday while allowing low winter sun to penetrate and warm the space.”
Elizabeth Heaps, Pro-Vice-Chancellor for Estates and Strategic Projects at the University of York, added, “The Ron Cooke Hub has proved to be a huge success, being popular among students, staff and visitors and also now becoming the business meeting venue of choice for people from across the city. The great atrium provides a lively environment for interaction and collaborative working. The remarkable span of the Glulam unifies the whole atrium, creating an exciting and attractive space, with a soft acoustic.”
The timber used in the manufacture of both Kerto and Glulam is ecologically sustainable; wood is the only 100% renewable raw material and Metsä Wood’s timber is independently certified by the PEFC to meet environmental standards, which indicates that the wood meets the requirements of sustainable forest management. Kerto has also been granted the ISO 9001 quality certificate and in common with all Metsä Wood engineered wood products, has the additional benefit of being fully CE Marked.
Kevin Riley, Vice President Construction Industry for Metsä Wood, said: “This project is a great example of the capabilities of both Kerto and Glulam, while illustrating the effectiveness of combining wood, steel and glass within a roofing solution.”