Liam Dewar, the director of Eurban Limited in London, England presented Timber for the Masses at the Wood Solutions Fair in downtown Vancouver. Dewar discussed the evolution of mass timber in the U.K. It started with nail laminated timber (NLT) and its use was accepted and grew. He said that NLT does have some challenges as the product will only expand and not shrink, so being aware of the initial and subsequent moisture levels is important.
He showed a study showing that the number of heartbeats are reduced in a timber building and how it's better for human health.
"Timber should be used in all buildings," he said, and added that logistics can play a role in the use of mass timber as shipping large panels is a challenge and cranes are needed for installation. They've been using mass timber construction in the U.K. for the past 12 years and the rest of the world is catching up. He said a lot of lessons have been learned over those years. His firm is a consulting firm but also does on-site installation so they understand the entire process.
"Cost is not a driving factor for this type of construction," he said, adding it's roughly comparable, but that you get what you pay for. He said a designer or owner must have timber in mind from the very beginning. It doesn't work to plan a concrete building and switch to mass timber part way through.
This is because a consultant or timber engineer must be involved with the project from the very beginning to make it go smoothly. The bulk of their projects are in the $200,000 to $1 million range. About half their project are that size, but that wasn't always the case. His firm started with smaller projects and the scope gradually increased as the use of mass timber became more accepted. Dewar is now discussing carbon emissions and the sequestering properties of wood and therefore mass timber.
"We have to use more timber in construction to deal with the carbon emissions," he said.
He said there are two options to deal with this. They are to build more buildings or use more wood in existing buildings.
"Another way of delivering timber to the masses is to building more buildings" he said.
He's showed an example of a mass timber building in the U.K. that his company was involved with. Concrete was used the project as it the case with most building projects.
"That's not going to change," he said.
He also discussed the flexibility of mass timber products, and cited the example of a recent building project, where the concrete was poured to the wrong height. However the mass timber product could be cut to fit, even though it wasn't their mistake, to make it work. Dewar said you can't do that with pre-cast concrete or many other building materials.
He said innovative design can be achieved, but it depends on the manufacturer as well as the installer. He stressed that an experienced and capable installer is necessary to make mass timber projects work.
He also mentioned Bridgeport House, where a comparison was done using different building materials.
Concrete Frame Construction would take 236 concrete deliveries, 10 rebar deliveries and 25 site operatives. Mass timber construction, by comparison, would require 30 timber deliveries, one steel delivery and only seven site operatives. The mass timber construction also reduced the overall building schedule by 40 per cent.
He said it was an easy decision to make when the facts were on the table.
He said his firm also had to deal with a lot of misinformation when it came to fire resistance, and it became their job to explain and educate about mass timber's benefits and properties. Dewar said managing moisture is an important aspect of mass timber construction.
His firm builds temporary drains and seals valleys. Moisture management can also include dying out.
"There's no way to avoid it in larger projects," he said.
His company now inspects concrete slabs two weeks before the mass timber panels are delivered on site to avoid issue with scheduling and to avoid cost.
The Wood Solutions Fair is taking place at Vancouver Convention Centre on Oct. 27. The fair is dedicated to design and construction with wood and wood products. This one-day educational event is hosted by the Canadian Wood Council and Wood WORKS! BC. Keep checking back for videos and stories from the event.