Racquet Centre roof with wood elements

The Hurlingham Club is a green oasis of tradition, renowned throughout the world as one of the largest private clubs. Adjacent to the Thames in Fulham, London, the Club provides to its members modern facilities and services among 42 acres of beautiful gardens.

The Racquet Centre, designed by David Morley Architects, has a sunken low-profile shape and a curved green sedum roof to minimize the environmental impact of the building.

Solid sound absorption with Kerto® LVL elements

The Hurlingham project involves the construction of a sports complex including four indoor tennis courts and four squash courts. The hall is 35m wide and 55m long. The main span consists of suspended steel beams. To give the courts space and reduce the cost of these complex beams, they are placed with large gaps of 12.9 meters. To fill these gaps, the architect wanted to see wood. Moreover, he demanded the construction a solid sound absorption to reduce reverberation in the hall.

The Kerto® LVL elements used in this project are very different from the normal Kerto-Ripa® construction, where the Kerto-S LVL ribs are 600 millimeters high, and the top plate is a 25 millimeter Kerto-Q LVL panel. Part of the brief was to come up with a solution that allow the acoustic panel to be part of the Kerto-Ripa elements.

The bottom plate again was made of a 20 millimeter Kerto-Q LVL. However this is a special configuration of Kerto-Q LVL called SONANS acoustics panels (perforation dia 10 @ 20 millimeters), with 50 millimeters of acoustic insulation internally within the panel allowing a high absorption coefficient required in the tennis hall (sound absorption coefficient: αw = 0.75- class C).

Wooden roof elements bear their long spans on a bow string steel truss

The architect and principal engineering office Price & Myers sought an efficient, lightweight solution for the wide span. Traditional laminated timber, combined with a solid wooden panel on top of, was found to have a height of 1200 millimeters for the beams, which was much too high.

The engineers at Price & Myers contacted Metsä Wood to look at a design with a shallower construction for the roof, but that would still accommodate the large span and heavy green roof.Following a joint design effort, they agreed a roof design with Kerto-Ripa elements. These elements are made from Kerto LVL using structural gluing. With any other material, trusses would have had to be more densely spaced.

The Kerto-Ripa elements constitute the vaulted roof construction are 12.9 meters long and have a total height of 645mm and maximum width of 1200 millimeters. To accommodate the curve of the structure four different widths were determined 550 mm, 600 mm 700 mm, and 1200 mm, totalling 140 prefabricated Kerto-Ripa elements. The roof elements fit flush with the vaulted, spaced, bowstring steel truss. To get the steel element the same depth as the Kerto-Ripa elements (645 millimeters), the steel manufacturer was heavily involved.

BIM technology resulted in a perfect match

With the arch in the roof, the supports and the installation process had to be considered at design stage in order not to have avoid difficulties any problems during while the erection of the roof.

In the first design team meeting with the contractor, architect, engineers and steel manufacturers, it became clear that the complex shape and the long span of the roof would require close collaboration of all team members. The depth of the Kerto-Ripa elements determined the depth of the curved steel member, as the steel had to be flush with the elements to accommodate the green roof structure above. The connection detail between the Kerto-Ripa and the steel element had to therefore be very carefully designed.

The BIM models that the steel manufacturer and Metsä Wood exchanged also allowed for all the connectors in the steel to be visible, so the panels could be modified to allow for installation and connections without problems on site.