A smile for CLT

Materials World magazine
2 Nov 2016

As part of the 2016 event, London Design Festival displayed architect Alison Brooks’ Landmark Project – The Smile – at Rootstein Hopkins Parade Ground in London. The 34m x 3m structure is a four-sided upward curving tube with open ends. 

The Smile is made entirely of tulipwood – 12 industrial sized cross-laminated timber (CLT) panels – with six curved panels running up to 14m long and 4.5m wide. It is held together with 4,000 screws more than a foot long, and kept from rocking by a wooden cradle filled with 20 tonnes of steel counterweights.

Arup project engineers assisted in the design of the piece, making sure the two 12m cantilevered arms did not turn into a seesaw. Andrew Lawrence, Associate Director of Arup, has claimed that The Smile is the most complex CLT structure ever built, and is the world’s first hardwood ‘megatube’. The American Hardwood Export Council also collaborated on the project. 

CLT is a very strong, yet light, material. It can be accurately machined by computer and assembled like flat pack furniture. Timber also has the benefit of providing vast stores of carbon. The material has the appearance of hardwood, is fast growing and is relatively inexpensive. Brooks has said that the project was an opportunity to stretch the limits of CLT, breaking with the conventions of inhabitable architecture. 

The Smile is accessible and features two viewing galleries – one at at either end. The exhibit is intended to create an immersive environment through the use of structure, surface, space and light.