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Old Posted Mar 21, 2012, 8:18 PM
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The Case for Skyscrapers Made of Wood

http://www.theatlanticcities.com/des...comeback/1554/

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The Case for Skyscrapers Made of Wood

Samuel Medina
2:56 PM ET
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Since the invention and development of steel and concrete, the combination of which would spawn the birth of the skyscraper, wood as a building material has been marginalized as simple construction ephemera, used to form concrete or to structure building frames advanced with the expressed purpose of producing single family homes or large estates and to furnishing their plush interiors.

Wood fell out of vogue in a large part because of its vulnerability to fire, probably the single greatest factor in restricting use of the material to smaller structures. But change is coming, writes CNN, as wood has become transformed by a handful of dedicated engineers and architects – Shigeru Ban most notable among them - and put to use in the service of large-scale structures like Michael Green‘s proposed “Tallwood” skyscraper in Vancouver.


Photo courtesy of Michael Green

The plans for the 30-story tower are among a small group of “woodscrapers” being proposed throughout the world, which all had to overcome stringent building codes. Explaining the motivation behind his design, Green says that wood construction at such scales is decidedly cheaper than standard-industry methods and, more importantly, much more energy efficient, given the large amounts of CO2 expended in the manufacturing of steel and concrete and the extent of their large carbon footprints. Conversely, wood traps carbon dioxide throughout a building’s life cycle, and, if sustainably harvested from controlled and well-managed forests, can prove to be a renewable resource.

...
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Old Posted Mar 21, 2012, 10:37 PM
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Nice idea,but can wood support the weight of a building in the same way steel does? After all, isn't that another reason why the latter became the predominant component for building skyscrapers?
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Old Posted Mar 22, 2012, 5:59 AM
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As the posted article notes, wood has a poor resistance to fire, which led some cities to ban wood construction for taller structures, particularly in Chicago and New York where modern skyscrapers were developed. Since wood was banned as a structural material in these main skyscraper markets, the tools and strategies for designing skyscrapers with wood were never really developed.

Strength wise, wood fares fairly well. In compression, wood is actually about as strong as concrete, while being much lighter. Wood also compares favorably to steel, since although steel is much stronger, it's also quite heavier. Wood's light weight is an advantage in earthquake prone areas.

Here's a chart of the strength to weight ratio(ksi/SG) for some varieties of wood and steel and concrete.

Data from http://workshopcompanion.com/KnowHow...d_Strength.htm

Other difficulties with designing with wood are that the strength changes with moisture content and direction of grain. For a lowrise structures, it's ok to overcome these uncertainties with deliberate overbuilding, but for a skyscraper, it's necessary to have a more consistent material.
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Old Posted Mar 22, 2012, 6:22 AM
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Well then, this may be the time for Vancouver to actually be another innovator city in the development of the skyscraper. North America has enough land to develop tree farms to grow the species that will be needed to build many of these "woodscrapers".
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Old Posted Mar 30, 2012, 2:23 AM
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Originally Posted by scalziand View Post
As the posted article notes, wood has a poor resistance to fire, which led some cities to ban wood construction for taller structures, particularly in Chicago and New York where modern skyscrapers were developed.
Not necessarily true...and damn is this a headache to prove it when it comes to building codes into Chicago. Try converting a warehouse built of wood into a high school!! It can be done, despite that code doesn't allow it.

Heavy timber actually has self insulating properties. If you've ever chopped through a thick log that's been burning in a fireplace, you'll find the core unburned. Usually heavy timber exposed in building fires can maintain its strength and unlike steel, not warp and bend from heat that would cause stress on the rest of the structure.

Basic fireinsulating solution is the same. Encase the columns in several layers of sheetrock.

If there's ever is a fire, replacement of members is fairly easy. It's resilient construction to damage.

Where you hear all the bad stories is when a house or apartment built out of 2x4's and 2x10's burns to a crisp....obviously because the stud-wall construction has thinner members, and more edges to catch fire.

Some of the drawbacks to wood construction will be flooding, pests, and mold. I realize there's tons of treated wood products out there that claim to defeat all of these problems, but I question the longevity of resistance, and I still have not done enough research on their health effects. Basically, I don't know what kind of treated wood is required for high-rise construction versus a low rise...which we know has little or no EQ issues.

Basically, I'm only convinced on engineering and life safety part of it which are the biggest hurdles to win over skeptics. I'm happy with the sustainability aspect too.
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Old Posted Mar 30, 2012, 1:49 PM
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And what happens if the big bad wolf shows up? Wooden skyscrapers would be more than likely be susceptible to hurricanes and stuff.
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Old Posted Mar 30, 2012, 9:51 PM
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And what happens if the big bad wolf shows up? Wooden skyscrapers would be more than likely be susceptible to hurricanes and stuff.

In japan they have what one might call proto-skyscrapers. Their called pagoda towers and while I will admit their not that tall. They have more in common with modern skyscrapers than your typical wooden structure in that they are both earthquake resistant (some actually have tuned mass dampers) and hurricane resistant ( Japan gets hit with bigger hurricanes than we do e.g. typhoon tip).

As Hayward said the main issue is fire-proofing. Several pagoda's of antiquity have been destroyed by fire.

http://www.jappleng.com/articles/vie...da-and-history


http://en.wikipedia.org/wiki/File:Horyu-ji09s3200.jpg
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Old Posted Mar 31, 2012, 12:06 AM
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Actually wooden skyscrapers could probably take place in developing or undeveloped countries. Since these nations have a lower GDP they can afford to construct a wooden skyscraper. Wood would serve as a fine gap between traditional houses and steel skyscrapers.
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Old Posted Mar 2, 2015, 2:25 AM
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Five floors is the maximum allowed for wood buildings by code in most jurisdictions in the United States.

Los Angeles recently started allowing seven floors. Here's the result:


http://cdn.abclocal.go.com/

Those flames are several hundred feet tall. It was a long horizontal building, 7 stories of wood, like a skyscraper on it's side, and the fire spread horizontally. Imagine if it were as tall as it was wide, the flames would have been over a thousand feet tall.

Built with all the modern fireproofing materials and requirements.

This building wasn't fully built, but was up to the full height, so luckily not open yet and no occupants were killed.

They can add as much fire prevention as they want to wood, and it might actually prevent some small fires from turning into big fires, but once the fire starts and takes hold of a tall wood structure, all bets are off. Your fireproofing better be solid rock.


http://cdn.abclocal.go.com/

Also, most of the tall wood buildings in Los Angeles are extremely ugly. Developers who skimp on materials usually don't hire quality architects.

If downtown LA gets hit with a 6 magnitude earthquake, you can expect to see several of these burning at the same time, probably with people in them, and no water to fight it because the water mains will most likely break in the quake. 110 buildings burned down in the Northridge quake fire.

Last edited by mdiederi; Mar 2, 2015 at 3:33 AM.
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Old Posted Mar 21, 2015, 6:26 AM
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Originally Posted by mdiederi View Post
Built with all the modern fireproofing materials and requirements.

This building wasn't fully built, but was up to the full height, so luckily not open yet and no occupants were killed.
Exactly. The fireproof materials, namely the double drywall and the sprinklers, hadn't been installed yet. There have been other fires like this during construction, like the one in SF Mission Bay a little while ago, but once everything's in these buildings have a good safety record.

Even-taller wood buildings use a very different material. Cross-laminated timber is a heavy-frame ("massive timber") material, akin to the giant logs that wooden lofts use but made from smaller bits of wood.
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Old Posted Apr 28, 2015, 4:40 PM
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Originally Posted by paytonc View Post
Even-taller wood buildings use a very different material. Cross-laminated timber is a heavy-frame ("massive timber") material, akin to the giant logs that wooden lofts use but made from smaller bits of wood.
^ and are far less susceptible to shrinkage over the long term as compared to heavy timber construction.
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Old Posted Jun 7, 2015, 8:31 PM
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World’s tallest wood building proposed in Paris could store 3,700 metric tons of carbon

Read More: http://inhabitat.com/worlds-tallest-...aris-by-mga-2/

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Michael Green Architecture (MGA) just unveiled a proposal for a carbon neutral wooden skyscraper in Paris that, if constructed, will be the world’s tallest wood building.

Created in collaboration with DVVD and real estate developer REI France, the wooden skyscraper—dubbed the Baobab—was designed as part of the city’s Réinventer Paris, a competition seeking innovative and environmentally friendly urban projects. The designers estimate the 35-story wood high-rise could sequester 3,700 metric tons of carbon—an amount equivalent to keeping 2,207 cars off the road for a year.

MGA is no stranger to tall wood architecture; the Vancouver-based architecture firm designed North America’s tallest wood building and has even published a study, The Case for Tall Wood Buildings, that explains the many sustainable benefits of timber buildings. This study and Principal Michael Green’s 2013 TED talk on the subject have helped spur the popularity of wooden buildings worldwide.

The proposed carbon-neutral Baobab is designed as a mixed-use development that combines mixed-income housing with a student hotel, urban agriculture, a bus station, e-car hub, and more. Conceptually located in Paris’ Pershing Site, the Baobab would span the eight-lane Peripherique.

.....



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Old Posted Sep 11, 2015, 12:21 PM
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Quote:
Originally Posted by mdiederi View Post
Five floors is the maximum allowed for wood buildings by code in most jurisdictions in the United States.

Los Angeles recently started allowing seven floors. Here's the result:


http://cdn.abclocal.go.com/

Those flames are several hundred feet tall. It was a long horizontal building, 7 stories of wood, like a skyscraper on it's side, and the fire spread horizontally. Imagine if it were as tall as it was wide, the flames would have been over a thousand feet tall.

Built with all the modern fireproofing materials and requirements.

This building wasn't fully built, but was up to the full height, so luckily not open yet and no occupants were killed.

They can add as much fire prevention as they want to wood, and it might actually prevent some small fires from turning into big fires, but once the fire starts and takes hold of a tall wood structure, all bets are off. Your fireproofing better be solid rock.


http://cdn.abclocal.go.com/

Also, most of the tall wood buildings in Los Angeles are extremely ugly. Developers who skimp on materials usually don't hire quality architects.

If downtown LA gets hit with a 6 magnitude earthquake, you can expect to see several of these burning at the same time, probably with people in them, and no water to fight it because the water mains will most likely break in the quake. 110 buildings burned down in the Northridge quake fire.
Exactly wooden structures are far too risky. They catch fire easily and burn down pretty fast .If you happen to live on the top floor and the building catches fire, you won't
have the time to escape.
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Old Posted Nov 19, 2017, 6:08 PM
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Originally Posted by samsonawane08 View Post
Exactly wooden structures are far too risky. They catch fire easily and burn down pretty fast .If you happen to live on the top floor and the building catches fire, you won't
have the time to escape.
That's ridiculous. Do you think these building don't have sprinkler systems when completed? That fire occurred when the building was under construction, at it's most vulnerable state.
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Old Posted Oct 5, 2015, 5:26 PM
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A Spectacular $350-Million Wood Pagoda Design By Herzog & de Meuron Unveiled for New Vancouver Art Gallery:

http://mashumashu.com/vancouver-art-gallery/

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Old Posted Oct 13, 2016, 1:47 PM
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Quote:
Originally Posted by mdiederi View Post
Five floors is the maximum allowed for wood buildings by code in most jurisdictions in the United States.

Los Angeles recently started allowing seven floors. Here's the result:


http://cdn.abclocal.go.com/

Those flames are several hundred feet tall. It was a long horizontal building, 7 stories of wood, like a skyscraper on it's side, and the fire spread horizontally. Imagine if it were as tall as it was wide, the flames would have been over a thousand feet tall.

Built with all the modern fireproofing materials and requirements.

This building wasn't fully built, but was up to the full height, so luckily not open yet and no occupants were killed.

They can add as much fire prevention as they want to wood, and it might actually prevent some small fires from turning into big fires, but once the fire starts and takes hold of a tall wood structure, all bets are off. Your fireproofing better be solid rock.


http://cdn.abclocal.go.com/

Also, most of the tall wood buildings in Los Angeles are extremely ugly. Developers who skimp on materials usually don't hire quality architects.

If downtown LA gets hit with a 6 magnitude earthquake, you can expect to see several of these burning at the same time, probably with people in them, and no water to fight it because the water mains will most likely break in the quake. 110 buildings burned down in the Northridge quake fire.
I just finished reading Strangely Like War, The Global Assault on Forests by Derrick Jensen, and I'm more spittin' angry/revolted by lumber companies than ever before!

If you can save a forest, and all the creatures that become extinct, who have lost their homes, and stop the clear-cutting which draws scavengers like deer and increases the risk of forest fires, then use some other material to build. I also read that tree farms only have 3 life cycles and kaput! Then what?

It's no surprise that lumber companies are among the most powerful lobbyists on a state, country, federal level, insisting everything be built out of wood, and lying about how much more expensive it is to build with concrete.

In Mexico, the concrete firm, CEMEX, is on a par with our lumber companies, except they insist everything be built with concrete. I had a house designed for me in Baja and tell me about it! Even a concrete roof, for a rooftop patio, and would I ever fear a brush fire consuming my all-concrete structure? All my travels through both Mexico and Central America I noticed just about everything built with concrete, houses, apartment buildings, motels, etc.

It's a crying shame that wood construction is foreign to the Mexicans, and when they come here, they trade in their masonry talents for wood construction, and a missed opportunity to employ them to build more durable structures in this country.

I am so, so, so fearful of fire, it's ridiculous! At least my townhouse has cinder block walls going up the entire 2 floors, and when I unit burnt out in my neighborhood, the unit burnt out, it didn't effect any neighbors.

I'm gearing up to move to Tucson to retire, and I already have my eyes set on one of those many 1960's/1970's slump brick or cinder block one story patio townhouses, only the roof is built with wood.

I would never consider living in an all wooden structure, even if the rent was free! And these developers have the nerve to slap the word Luxury on to the building! Fireproof = luxury to me!

I get saddened everytime there's an apartment fire in this city, and tenants are forced to evacuate in the middle of the night, all which could be preventable with concrete construction, concrete walls separating the units.

What's really a frightening idea is if there's ever widespread anarchy in this country, one day, on a windy night, think of what all could burn down in just one night!

Here, in Las Vegas, with many houses built a mere 10 feet apart, and with our wind blasters that come through here at 50-60MPH, imagine!!! All it would take is one Molotov cocktail hurled into someone's living room window to get it all started!

Ah Well! Enough ranting about the widespread Weyer-haus-ing in this country!
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Old Posted Dec 21, 2016, 6:25 PM
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'Glue' that makes plant cell walls strong could hold the key to wooden skyscrapers

Read More: http://phys.org/news/2016-12-cell-wa...ey-wooden.html

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Molecules 10,000 times narrower than the width of a human hair could hold the key to making possible wooden skyscrapers and more energy-efficient paper production, according to research published today in the journal Nature Communications.

- The two most common large molecules - or 'polymers' - found on Earth are cellulose and xylan, both of which are found in the cell walls of materials such as wood and straw. They play a key role in determining the strength of materials and how easily they can be digested. --- For some time, scientists have known that these two polymers must somehow stick together to allow the formation of strong plant walls, but how this occurs has, until now, remained a mystery

- "We knew the answer must be elegant and simple," explains Professor Paul Dupree from the Department of Biochemistry at the University of Cambridge, who led the research. "And in fact, it was. What we found was that cellulose induces xylan to untwist itself and straighten out, allowing it to attach itself to the cellulose molecule. It then acts as a kind of 'glue' that can protect cellulose or bind the molecules together, making very strong structures."

.....
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Old Posted Jan 11, 2018, 6:57 PM
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https://archpaper.com/2018/01/interv...r-tower-audit/


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.....

- Mass timber is a major structural element of an increasing number of skyscrapers, according to a CTBUH survey; now, the fire codes just have to follow.

.....



The proposed Perkins + Will-designed River Beech Tower, if built, would be the tallest wood structure at 80 stories. Currently in a conceptual phase, the design calls for the use of easily available commercial wood products. (Courtesy Perkins + Will)






The interior of the central atriums would feature bridges that link the tower’s two hemispheres. (Courtesy Perkins + Will)

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Old Posted Mar 31, 2012, 5:04 AM
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And what happens if the big bad wolf shows up? Wooden skyscrapers would be more than likely be susceptible to hurricanes and stuff.
It probably wouldn't be a good idea in areas with a lot of hurricanes...or even humid weather. Even if the building isn't damaged by strong winds, water that's seeped into the walls will do the rest. Sure, plenty of wood buildings have been fine in places like Florida. But how does one easily swap out a ton of moldy lumber and keeping a tall building plumb and level after repair.

And tornado areas...don't even think of it. Even Steel buildings don't fare well.

Maybe someday reinforced concrete will become more sustainable. There's GFRC, but it's usually limited to decorative elements and cladding.
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Old Posted Mar 31, 2012, 3:01 PM
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And then there's termites and other unwanted guests.
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