Solid Wood Solutions

Materials World magazine
,
3 Nov 2015

The Solid Wood Solutions conference celebrated some of the most successful engineered timber projects in the UK. Khai Trung Le reports.

The phrase ‘drop in the ocean’ was a recurring motif at the Solid Wood Solutions conference, an intimate gathering held at the London Inmarsat Conference Centre on 16 September. ‘It is a small industry – the people here are the key players, you can still fit everyone together in one room – but with a lot of growth potential,’ said Ralph Pelly, Senior Structural Engineer at Rise Structures, UK. The phrase was heard in networking sessions and conference panels, to describe anything from the size of the industry to the significance of the conference attendees. But there is plenty of optimism in the industry, as architects and contractors develop more interest in timber, and awareness escalates with each project undertaken.

Pelly continued, ‘Showcasing solid timber and what it is capable of, as it begins to be acknowledged for its architectural qualities rather than the simple fact that it is made out of timber, will be the point where the rest of the construction industry will realise it’s not just a green thing, but a viable option that has benefits beyond the environmental.’

Matthew Blaza, Senior Engineer at Integral Engineering Design, UK, added, ‘I think engineered timber is becoming an increasingly viable alternative to steel and concrete, and while other composites are a niche area for specific uses, timber is potentially viable as an option in a lot of projects that it isn’t currently being considered for. A huge, high-profile project – like an Olympic stadium in timber – would really launch public awareness, and increase its uptake.’ 

Canary Wharf

While not an Olympic stadium, the Canary Wharf Crossrail Station is arguably the largest engineered timber contract in the UK. Its roof, with around 1,500 glulam (glued laminated timber) members shielding the four-storey subterranean structure, was designed by architectural firm Foster + Partners, who collaborated with Austria-based Wiehag Timber Construction in the earliest stages of the project. Foster + Partners states that glulam was chosen to provide a ‘warm, natural counterpoint to the steel and glass towers of Canary Wharf’, and John Spittle, Sales Director at Wiehag, attributes this early engagement with the successful completion of the roof section.

‘It was very unusual. Originally, it was just going to be a box, but the Canary Wharf Corporation, their contractual arm, wanted this to be a landmark. Some “wow factor”, with an unusual – especially for Foster – timber solution. So they got in touch back in 2009 when they started the competition with Foster. We were involved very early on and doing so meant the client, architect and engineers got what they wanted. Canary Wharf was delivered ahead of time and on budget, and looks the way it was designed. That normally doesn’t happen.’

Like most of the delegates, Spittle hopes that the position of the Canary Wharf Crossrail Station will raise the profile of engineered timber as a valued construction material. ‘Usually these timber projects are out in the sticks somewhere, but this being right in London’s second financial centre is unusual, and I don’t think you’ll see another like it in the city for a long time. As we understand it, it is one of the most expensive glulam projects in the UK to date.’

Engineered timber is also experiencing uptake in other areas, including numerous mid-rise flats in Hackney, London. Andrew Waugh, co-founder of Waugh Thistleton, UK, remarked on the success of Murray Grove, Waugh Thistleton’s first endeavour with cross-laminated timber (CLT) which, at nine storeys, was previously the world’s tallest timber residential building until Australia’s Forté tower was built in 2012. ‘Our developer client sold the 29 flats in this building in an hour and 15 minutes. Only three people have moved out since it was finished in 2009. They aren’t investors and these aren’t buy-to-let flats. People moved into these spaces because it was made out of timber, and that’s exciting to us.’

However, the case studies were not without upsets, with Liam Dewar, Director of Eurban, UK, addressing the closure of Malcolm Fraser Architects, which entered liquidation in August 2015. An avid timber supporter, Malcolm Fraser was quoted in Dewar’s panel, saying, ‘The work we did is beautiful and important. However, we have been unable to make it profitable.’

Drop in the ocean

The qualities of engineered timber detailed throughout the day were numerous, with its environmental benefits, natural insulation and thermal and dimensional stability among the most touted. Engineered timber projects are regarded for their ease of installation, greater strength and reduced moisture content over solid timber. The capacity to incorporate factory-produced components also increases the scope of engineered timber, allowing for its use in mid- and high-rise buildings.

Waugh believes that the proliferation of timber as a construction material will eventually come. ‘Climate change is probably the primary concern of our generation, and ultimately it all comes down to mitigating CO2 emissions, and enhancing sustainability in construction. Carbon taxes are inevitable, and when they come in, Liam [Dewar] and I will be old men, shaking our heads.’ He notes, though, that the environmental benefits may not be the best selling point. ‘We’ve found that sustainability is never a priority. So we have learned to argue the benefits of timber on price, on ease of follow-on trade, and the beauty of living in these spaces.’

As well as environmental benefits, Dewar spoke about health issues. ‘Beyond the moisture and thermal stability, recent research has revealed that timber is very good for us. Not just in comfort levels, but also in a physiological sense, in terms of our heart rate.’ Both Dewar and Arup’s Tim Snelson referred to the 2011 study Interior wood use in classrooms reduces pupils’ stress levels, published on the 2011 Environmental Psychology conference website, in their panels. Conducted by the Medical University of Graz and Institute for Health Technology and Prevention Research, Austria, the study found that ‘over the course of a school year, pupils’ heart rate significantly decreased in the solid wood classrooms’, as well as a ‘decline in perceived stress from interactions with teachers’.

However, awareness of these benefits outside of the industry is currently very low. Dewar remarked, ‘As much as we’ve got an audience here, it’s a drop in the ocean. That’s a shame, because I think everyone here realises the huge potential of timber. It’s wrong to ignore them, and my general pessimistic view is that there is too much vested interest in not doing it, actively trying not to use CLT, and I can’t believe that some people can’t see the value of it!’ Waugh added, ‘We used to battle against very conservative developers, but nowadays it’s conservative contractors who we struggle with. It is, as Liam insists, adherence to these tried-and-tested ways of doing things, where people have clear paths to profit and don’t want to shake that up.’

This lack of interest is perhaps not being addressed by the timber industry successfully, and Blaza remarked, ‘It’s much easier to talk internally to people who already believe. The challenge is reaching the wider world, and the industry is not necessarily good at it.’

Perhaps it is Snelson’s unholy truth that needs confronting before engineered timber becomes as prevalent as the Solid Wood Solutions attendees would like, ‘At the moment, the timber building is more expensive than the concrete building. That is the challenge for us as an industry to get the timber system as competitive as possible.’