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Comment by dmitri1981 | Hacker News Reader

dmitri1981

Several comments have mentioned that sand is not a renewable resource and the need for alternative building materials. Where I live in Hackney in London there has been a gradual increase in the number of buildings built using cross-laminated timber. It offers huge benefits over concrete, it is a renewable resource and much lighter than concrete. Despite expectations the buildings are still just as fire proof as concrete and can be constructed up to 10 storeys high. There are 23 such buildings either built or completed in Hackney.

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If they started building so massively and anarchically with timber, it would likely be even worse. Illegal cutting, mud slides, complete destruction of rivers, massive building fires.

The place could turn into a desert.

You likely can't fix this with some simple technological measure. There are just too many people who want to improve their material standard of living. They have the tools and it's a tragedy of the commons from there on.

Glulam beams are actually pretty ecologically sound. They're made from laminations of smaller pieces of wood, so there's less demand for old-growth trees. It can also be made of the smaller pieces left over from cutting larger pieces. And of course, trees are a renewable resource, if managed right via sustainable forestry.

Another benefit to them is that a single glulam beam can replace several ordinary dimensional pieces of lumber. So you end up using less wood because they're stronger.

And when used as architectural elements, they're attractive.

https://www.apawood.org/glulam

I'm more than a little bit suspicious of these glues. They form moisture barriers for one. How is the longer term durability (100, 200, 300 years)?

The ones I know about are coming up on 55 years in use and still look good. I expect as long as you keep them dry and insect-free they'll last a long time.

Sustainable timber production is a solved problem, opposing wood use in general (as opposed to specifically, when done using problematically sourced timber) is counterproductive.

Also, I recall reading that most old-growth forest clearance is to free up the land for agriculture, not primarily to produce timber, so timber buildings aren't causing this.

>>Sustainable timber production is a solved problem

At current demand levels, yes. But if we're talking about replacing concrete with timber, you're going to find it difficult to keep timber production sustainable, since it will have to massively increase to meet new demand.

It's a good thing England and the UK have never had problems with overcutting timber, or deforesting Great Britain or Ireland.

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Engineered lumber is quite common in the US for smaller buildings. When we renovated our house, the builder used an I-beam made of such material. I would be interested to hear if this is also being used for larger structures - I doubt if it would be possible to make a 10 story building out of wood.

http://www.abc.net.au/news/2017-02-25/all-timber-apartments-...

Saw this recently on this subject.

My uncle works at a company that's involved in this proposed 11 story wood building in Portland: http://www.nextportland.com/2016/07/21/framework-dz1/

Their projects page lists a couple of other buildings: https://structurecraft.com/projects

Can't find a link right now, but I did read an article on skyscrapers being designed out of engineered timber. I think it is something about using the whole box as structure, whereas in a steel building the curtain walling is just dead load. We simply cannot keep building out of concrete, as this story shows.

We all have the same doubts about wood. Seeing skyscraper scaffoldings in bamboo might change our perception of physics ;) https://www.google.fr/search?tbm=isch&q=bamboo+scaffolding

I was against timber-based construction. Mostly for esthetic reasons. I associated cheap construction with sprawl, waste.

I now think the impermanence is a feature, not a liability. It's fine for a building to last just 20, 40, 60 years. And then get torn down and have the land repurposed.

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