Light touch

From the upgrade of spectator and hospitality facilities to retractable seating to bring fans closer to the action for football and rugby, the highlight of the newly transformed Olympic Stadium is undoubtedly the ambitious new cantilevered roof, which at twice the size of the original, covers every seat in the house.

The new look stadium’s impressive redevelopment by Balfour Beatty has seen the venue put back on the world stage. In what is a feat of design, production and delivery logistics, a critical element of the stadium’s massive new transparent roof canopy is the inclusion of Marlon CS Longlife polycarbonate sheeting from rooflight manufacturer Brett Martin.

Stadium designers have recognised that by including translucent materials such as polycarbonate and GRP sheeting into stadia, they can not only make an architectural statement, but also ensure adequate daylighting reaches the grass, whilst at the same time protecting fans from the elements.

At the former Olympic Stadium in Queen Elizabeth Park, the striking new 45,000 m² roof is made up of two distinct sections – single ply membrane and polycarbonate – which run concentrically around the stadium. The iconic triangular lighting towers have been reintegrated below the roof, inverted from the old position on top of the old roof.

“With a depth of 84 m, the new roof is the largest gravity supported cantilevered roof in the world and covers all of the 54,000 seats in the stadium,” commented Tom Ogilvie, managing director of Brett Martin Daylight Systems. “As the old fabric roof only covered 40% of spectators, the new roof improves acoustics by reflecting the noise of the terraces and projecting it towards the pitch.”

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The cantilevered roof incorporates 87 tonnes of Brett Martin’s polycarbonate made up of 4,484 Marlon CS Longlife profiled sheets to form the front, more steeply pitched section. The polycarbonate will bring natural daylight into the stadium, ensuring optimum grass growth and pitch perfect conditions whilst protecting fans from the elements.

The inclusion of polycarbonate in the roof canopy has enabled the stadium designers to offset the amount of steel used and achieve a roof structure which would simply not have been possible at this scale otherwise. The polycarbonate covers 50% of the roof structure, but at 87.5 tonnes in total, contributes only 2% of the weight.

The Marlon CS Longlife rooflights were supplied in a stadia profile at 2 mm in thickness and in a special width to achieve the project’s specific spanning requirements.

“This was an exceptionally complex roof. We essentially had a circular roof of 56 bays which meant the outside edge of each section was wider than the inside edge,” added Tom Ogilvie.

Due to the complex truncated cone geometry of the canopy and the unique purlin structure, 38% of the Marlon CS Longlife sheets required for the project had to be individually taper cut to fit the intricate concentric roof structure. A total of 2,756 sheets required tapers to one or both ends and often along the length of the sheet to ensure end laps would align with the purlins.

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Brett Martin Daylight Systems
Sandford Close
Aldermans Green Industrial Estate
Coventry | CV2 2QU
0247 660 2022
www.brettmartin.com