REGULARS - TALKING TIMBER
The T3 building in the US . Image : Ema Peter
But rest assured , all the existing buildings , such as the built 14-storey tall timber Treet building in Norway , for instance , or 18-storey Brock Commons in Vancouver , would not have been built without careful , thoughtful scrutiny .
There are many ways to protect the wood . They include gypsum wall board and the natural charring ability of the wood itself .
For instance , there ’ s really rigorous research going on right now about how to measure that char layer . What that means is that when a heavy timber member burns , it burns in a very slow way from the outside in and tends to char over and protect the inner structural layers from being burned further . There are scientific ways to design so that in the rare case of fire or event when a system might fail and that member starts to burn , there could be a protection borne out by the natural wood properties to achieve standard two-hour fire rating .
If the testing bears that out , it will add a lot of momentum to the code process .
PGB : Will the tests next year dictate how the timber market and timber construction industry move forward in relation to commercial structures ? Jones : Once these tests results are in place , that will be the trigger . Once the codes committee – and I should stress that I don ’ t speak for the committee , I ’ m only one member of 18 – performs the tests and , assuming they ’ re performed at an acceptable level , once we have data that is very trustworthy and carefully thought out , the code committee will act quickly to assemble model code language . Once that goes ahead , it will go into a broader voting process sometime in early 2018 .
Once the language is assembled , even in draft form , it can be used by authorities and cities at their discretion . They ’ ll know it has been carefully scrutinised by an interdisciplinary body .
Everybody is waiting for that sweet spot to move quickly ahead for construction of taller timber buildings . The industry is aware that for multi-family buildings up to six storeys it makes sense to use light wood frame construction . But between seven and 14 storeys , it is usually too cost-prohibitive to use concrete or steel , and light frame wood is not allowed . So , once that height is allowed for mass timber buildings , I see the industry moving very fast to adopt mass timber construction .
It ’ s really exciting to imagine growing your own high-rise from a handful of seeds . It ’ s the only material that is renewable .
Source : Proud Green Building
52 APRIL / MAY 2017 //