" It ' s really exciting to imagine growing your own high-rise from a handful of seeds. It ' s the only material that is renewable."
REGULARS- TALKING TIMBER
If you imagine an equivalent to concrete or a precast concrete system, they’ re lighter than that and very strong. They can create a repetitive, modular system of construction.
That’ s a huge advantage to our contractors who, once the construction industry gets used to this system, they won’ t go back because it’ s such an easy modular way of putting things together on site, especially in tight urban sites. It’ s quicker, it reduces noise, reduces pollution with trucks and it appears that the schedule is impacted favourably to 20 to 30 %, which is no small amount when time is money. A lot of this, of course, depends on the individual project and consistency in the quality of design and shop drawing coordination that is executed by the architect. From a design point of view, it puts more control back into the architect’ s hand.
All of that work is done prefabricated in the factory before the panels even arrive onsite. So there’ s a great deal more work that’ s been done beforehand, but the architect takes charge of coordinating the panels with the fabricator directly. Depending how well the architect does, it can go together very fast with extremely tight and very precise tolerances. It’ s an exciting environment to work in when you’ re looking at really accurate millimetres or an eighth of an inch tolerances, which makes your finish work and exterior wall systems much easier to apply. It’ s a great material to work with.
Once contractors understand that and owners realise the benefits, that’ s going to be an advantage in the contracting industry.
Those of us deeply involved in this the past five or six years have been building that expertise to lead the process in a different way than the typical architect would lead a construction process or be part of a team. We’ re very conscious about being good, integrated design team players. It is a different role, but it’ s exciting for us who have been involved for a while and understand how to use it to everybody’ s advantage.
PGB: Is timber for every project? Jones: Most likely, yes. But the real barrier for taller buildings at the moment is codes. To answer that question appropriately, the answer is no. You can’ t build over six stories without special approvals. However, there’ s nothing prohibiting it in terms of its constructability or structural integrity.
One of the things that’ s been really exciting recently is to watch the( cross-laminated timber) framework building in Portland get closer to being approved by the municipal authorities. Portland is in a high seismic area, as is Seattle and Vancouver – the seismic codes are much more stringent on the West Coast than they are elsewhere in the country – so it’ s exciting to seriously consider building a 12-storey timber building in the next couple of years here on the West Coast.
That tells me the sky is pretty much the limit. If you look at it carefully, there’ s no technical reason why you can’ t go to 20 stories and probably 40. The real issue is codes, and the foundational issue, is fire codes. We can convince our
" It ' s really exciting to imagine growing your own high-rise from a handful of seeds. It ' s the only material that is renewable."
structural engineers that our buildings are safe. We can convince our structural reviewers that they’ re safe. The fire community has a longer way to go.
I’ m one of 18 national code committee members, and the national American Institute of Architects’ representative to the ICC. Most of the committee’ s focus has been on how to understand better and deal with fire concerns. If you look at the codes, and this gets a little technical, there’ s Type 1A and Type 1B and those buildings have a high height limit with what are considered non-combustible materials, which are steel and concrete. When you add a combustible material, such as wood into the mix, there are a series of concerns that need to be met.
We’ re going about that in a very methodical way. The good news is that the committee is functioning at a high level, all parties are involved, there’ s a considerable amount of give and take and scrutiny. The result is that we’ re creating some important fire tests that will be some of the most rigorous in the world happening in the spring. Funding has been procured for these million-dollar fire tests. They take several weeks to construct a two-story apartment dwelling with a stair core and a corridor to mimic real-world conditions. Then we’ re going to set the whole thing on fire five different times to see how it performs!
Assuming those fire tests go well – and we assume they will based on all of the other tests that have been done internationally and in Canada – I think you’ ll start to see some fast movement on the codes and things will fall into place very quickly in the next year or two.
PGB: As far as the discussion of regulations related to timber, are they centred on fire codes? Is there concern about strength and durability? Jones: The structural properties of the panels are fairly extraordinary. They have a very high level of shear and lateral resistance. Because the panels are lighter than typical concrete, the gravity loads are less and the foundation requirements, which need to be concrete, are known to be less.
Some of these aspects should continue to be tested, but I think there’ s a general acceptance in the industry about the structural issues. The fire question is an area we need to continue to be thoughtful and careful of and do strong research on.
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50 APRIL / MAY 2017 //