Heavy timber isn't all that much more dangerous than steel, which will deflect and fail when exposed to fire. I'm happy with the sustainability aspect too. 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.īasically, I'm only convinced on engineering and life safety part of it which are the biggest hurdles to win over skeptics. 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. Some of the drawbacks to wood construction will be flooding, pests, and mold. 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. If there's ever is a fire, replacement of members is fairly easy. Encase the columns in several layers of sheetrock. 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.īasic fireinsulating solution is the same. If you've ever chopped through a thick log that's been burning in a fireplace, you'll find the core unburned. Heavy timber actually has self insulating properties.
SKYSCRAPER MADE OUT OF WOOD CODE
Try converting a warehouse built of wood into a high school!! It can be done, despite that code doesn't allow it. Not necessarily true.and damn is this a headache to prove it when it comes to building codes into Chicago. 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.Īs 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. Other difficulties with designing with wood are that the strength changes with moisture content and direction of grain.
Here's a chart of the strength to weight ratio(ksi/SG) for some varieties of wood and steel and concrete. Wood's light weight is an advantage in earthquake prone areas. Wood also compares favorably to steel, since although steel is much stronger, it's also quite heavier. In compression, wood is actually about as strong as concrete, while being much lighter. 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. 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.Īs 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. 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. 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. 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. 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. 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. Quote: The Case for Skyscrapers Made of Wood
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