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The Case for Making Cities Out of Wood
- avoidwork 8y agoSome cities were wood, and they burned. My concrete condo is in the burn path of the 'great Ottawa fire'. Wikipedia doesn't have enough pictures, worth googling. https://en.wikipedia.org/wiki/1900_Hull–Ottawa_fire https://en.wikipedia.org/wiki/1900_Hull–Ottawa_fire
- bryanrasmussen 8y agoI'm wondering if 'total collapse of cell walls and the complete densification of the natural wood with highly aligned cellulose nanofibres.' means that stuff isn't going to burn until you get temperatures where steel melts anyway?
- farrisbris 8y agoIt would seem so. from the article: > Massive wood walls and structural beams and columns comprised of engineered panels have demonstrated fire performance equal to concrete and, in some cases, superior to steel
- singularity2001 8y agoone big difference seems to be that once the critical point is reached, even if the threshold very high, the wood contributes to the fire and nourishes it, unlike concrete or steal. a skyscraper with proper sprinkling should be fine.
- peterwwillis 8y agoTons of major cities have been wiped out from fire in the early 1900's. But you have to consider how ill-equipped they were to handle fire, not to mention a total lack of research. Modern cities have working fire hydrants and buildings can have multiple fire suppression systems. Most of this is due to those massive fires happening. Here is NIST's report on fire resistance of timber structures (https://www.nist.gov/sites/default/files/documents/el/fire_research/NIST-Timber-Report-v4-Copy.pdf https://www.nist.gov/sites/default/files/documents/el/fire_r...). It includes guidelines that help increase the fire safety of wood buildings. This page (https://www.firechief.com/2017/03/14/are-wood-frame-high-rises-a-fire-risk/ https://www.firechief.com/2017/03/14/are-wood-frame-high-ris...) shows CLT has had testing to approve it for use in 6+ storey buildings in multiple countries.
- fredley 8y agoThe case against: https://en.wikipedia.org/wiki/List_of_town_and_city_fires https://en.wikipedia.org/wiki/List_of_town_and_city_fires
- xigency 8y agoI think of Chicago first. The wood city that burned and led to the invention of 'skyscrapers'.
- nervousvarun 8y agoThe focus of this article is innovation in this space. What happened in Ottawa or Chicago or Tokyo is relevant in a historical sense but this is about recent innovations that make wood viable (both from a safety/fire-resistant perspective and economical).
- tyu1000 8y agoI think we all know this, but this article was less-than-convincing and nothing has been deployed at scale yet.
- bigpicture 8y agoChicago has a CLT building - the new flagship McDonald's restaurant is CLT and steel. Additionally, a CLT office building has been approved in Chicago and will be the largest CLT building in the United States when finished.
- deleted 8y ago[deleted]
- vvillena 8y agoThe kind of wood used here does not burn like normal timber. Its treatment gives it strength and fire resistance. There are some large scale tests that need to be done yet, in order to better understand how a fire would behave in a midsized wood building. It's all in the article. Keep in mind, this is way more testing than usual, lots of other materials have been used in large buildings, sometimes with disastrous consequences (see: Grenfell Tower fire).
- bl4ckm0r3 8y agoEmperor Nero likes this element!
- golergka 8y agoThree out of three top comments here are about fires - an issue the article specifically talks about. How about reading the whole piece instead of just a headline?
- senorjazz 8y ago> How about reading the whole piece instead of just a headline? Sacrilege! People don't have to read the article to have an opinion. This is the internet.
- dsfyu404ed 8y agoThe article does not address the topic in sufficient detail which is why people keep commenting about it.
- xigency 8y ago> He wants to do many more experiments because it’s still not clear how, in mass timber buildings, to get compartment fires to reliably burn out on their own, a “cornerstone of fire safety engineering design,” he writes. In this context, the article's later comparison of this wood to concrete seems exaggerated.
- netcan 8y agoFor the people saying "fire!"... Wood went out of fashion because of urban fires, resource (natural forest) depletion and long term maintenance (rot, termites..) issues. Modern engineered timber (according to proponents) solves these problems. It's engineered from renewable crops of fast growing timber, is resistant to fire and pests... Proponents claim it is now suitable for skyscrapers but certainly for 5-15 story urban residential buildings. Imo.. what is missing are clear advantages, a reason to bother. I don't think there's much cost advantage at this point. Weight savings.. maybe there are some applications where this is important. Generally, it's a bit of a solution searching for a problem.
- Fricken 8y ago> There is also, alongside the environmental and economic, an aesthetic-psychological case for wood cities. Clare Farrow, who is co-curating a current London exhibit called “Timber Rising–Vertical Visions for the Cities of Tomorrow,” wrote in Dezeen, Studies are showing that the presence, scent and touch of wood can have remarkably positive effects, not only on people’s wellbeing in a general sense, but more specifically on stress levels, blood pressure, communication, learning and healing.” A 2015 review in Wood Science and Technology supports her claims and also suggests that “specific aspects of wood such as colour, quantity, and grain pattern should be examined" Of course, I don't need a study to tell me that wood is nice.
- asdfasgasdgasdg 8y agoYou probably shouldn't be smelling or touching the wood frame of your home. If you do, there is a bad problem with your drywall.
- Fricken 8y agoHere, just take a look at this Google image search for cross-laminated timber architecture, it'll help you guys to make comments that aren't so ill informed and off-base: https://www.google.ca/search?biw=1919&bih=947&tbm=isch&sa=1&ei=DZ-8W5j8CMiG0wLg-qaQBg&q=cross+laminated+timber+architecture&oq=cross+laminated+timber+architecture&gs_l=img.3..0.15211.17212.0.17423.13.6.0.7.7.0.85.477.6.6.0....0...1c.1.64.img..0.13.487...35i39k1j0i67k1j0i24k1.0.G7W5yRYk6dE#imgrc=_ https://www.google.ca/search?biw=1919&bih=947&tbm=isch&sa=1&...
- tomrod 8y ago> A recent advance in wood technology should interest the neighborhood’s developers: Teng Li, a University of Maryland mechanical engineer, created with his colleagues wood that’s as “strong as steel, but six times lighter,” he said. Liangbing Hu, Li’s co-author on the study, added, “This kind of wood could be used in cars, airplanes, buildings—any application where steel is used.” Making it is just a two-step process. The scientists first boiled natural wood in a mixture of sodium hydroxide and sodium sulfite, to remove some of the lignin and hemicellulose, substances contained in the walls of wood cells (the former retard parasite and bacterial attacks, the latter cover and bind fibers). Then they put the wood in a hot press, which leads, as they say in the paper, “to the total collapse of cell walls and the complete densification of the natural wood with highly aligned cellulose nanofibres.” The result, they conclude, is a “low-cost, high-performance, lightweight alternative” to “most structural metals and alloys.” If this decreases the burn rate, as other commenters have pointed out, and the input energy is manageable, then this has a chance. Cool!
- perl4ever 8y agoThe obvious question, to me, is whether this process can be used to produce a uniform enough product to be highly reliable.
- lifeisstillgood 8y agoIf you can extrude or shape the densified wood, into something "branch-like" but at steel like strength then you open up new building opportunities - our cities are dominated by straight lines, for good reasons, but branchlike handrails, footpaths and arches open up a lot of possibilities for good architects to chnage the look of a city beyond the mere material it is made of
- ctack 8y agoThere is a compression step in wood preparation life cycle. You could replace this step with shaped moulds to create these features. Or maybe it's cheaper and easier to 3D route out of bigger masses.
- lifeisstillgood 8y agojust wondering how much pressure it takes to compress wood to destroy the cellular structure. One might suspect more than enough to crack a mould that had lovely curvy shapes in it ...
- chriswarbo 8y ago> Teng Li, a University of Maryland mechanical engineer, created with his colleagues wood that’s as “strong as steel, but six times lighter,” he said Phrases like this make me uneasy. "Strength", especially when used informally like this, is quite ambiguous (e.g. there's a reason we don't make buildings out of spider silk). Overall it's quite an uplifting piece though, and I would certainly like to see such a revival.
- m0llusk 8y agoFirst of all, what they are talking about is more like paper made out of wood since the fibers are treated extensively and then formed. Secondly, large and spreading structure fires which have such a devastating history have been essentially eliminated by use of sprinkler systems.
- vinayms 8y agoEven if the technology is perfected and proven superior on several counts, the adoption has to overcome the psychological barrier. The places that don't have a culture of wooden buildings, especially the floor, will need some convincing. As an Indian, I don't encounter wooden floor often. Modern buildings are all brick and reinforced concrete, and old temples are stone mostly. Any wooden floor one might come across are just wood panels installed on concrete floor. Nearly two decades back, the city library (Seshadri library, Bengaluru) was renovated, and as a part of it the shelves were raised and a wooden corridor was installed to enable access to higher shelves; its a tall building with a dome and a large hall under it, your typical library. Needless to say, I was quite apprehensive to walk on it, so were most people there. Apart from that, the only experience I have is standing on my desk to change the bulb. The desk is quite sturdy - the bulkier carpenter stood on it to demonstrate - but I just can't trust it the same way I trust concrete floor. When on a wooden surface, I step softly, hoping to make myself lighter, just in case, though I know its nonsense.
- crooked-v 8y agoWith the mention of temples, it's actually pretty common for historical temples, churches, and castles to have wooden rooms for anything past the ground floor, since it was much, much easier to build a few main structural supports out of stone and then fill in the rest with wood later. Of course, I'm a little biased on the subject, living in a 100-year-old all-wooden building (you can see the huge beams resting on the foundation in the basement) that I chose for earthquake resistance. I'm actually a lot more comfortable knowing that the whole building can sway while all the parts stay attached, compared to the many old brick buildings around here that will literally fall apart if an earthquake happens.
- pseudolus 8y agoThere are actually plans to build a 350 meter (approx. 1050 foot) skyscraper in Japan. https://www.dezeen.com/2018/02/19/sumitomo-forestry-w350-worlds-tallest-wooden-skyscraper-conceptual-architecture-tokyo-japan/ https://www.dezeen.com/2018/02/19/sumitomo-forestry-w350-wor... For those interested in more "concrete" expressions of the existing capabilities of timber based construction an 18 story dormitory was assembled in 70 days at the University of British Columbia. https://news.ubc.ca/2016/09/15/structure-of-ubcs-tall-wood-building-now-complete/ https://news.ubc.ca/2016/09/15/structure-of-ubcs-tall-wood-b... Here's a time-lapse: https://www.youtube.com/watch?v=GHtdnY_gnmE https://www.youtube.com/watch?v=GHtdnY_gnmE
- chasedehan 8y agoThe question I have about all of this is the environmental impact of the "densification of wood." They cite it being similar to paper manufacturing, which is really energy intensive and is a horribly polluting industry. I don't have any info on the above, but it is something I wonder about.
- specialist 8y agoI'm day dreaming about 'aktivhaus' (sp?) style residential in the desert. What would that look like? My starting notion is a three level structure. Bottom is carport, patio, storage. Middle would be kitchen, baths, common areas, study. Upper would be bedroom(s). Maybe a roof top deck. South wall would have horizontal solar louvres. Kinda like the Burr library in downtown Phoenix. Roof top solar something. But I'd still want to be able to look up at the stars. Grey water system of some sort. So the ground level would have a cistern of some sort. Is wood a viable option for the desert? I know zilch about thermal loads, insulation, etc. If so, how much wood?