
Canadian cities take wooden skyscrapers to new heights - perfunctory
https://www.theguardian.com/cities/2019/jul/22/canadian-cities-take-wooden-skyscrapers-to-new-heights
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xref
They glossed over the “wood is viewed as fire prone” thing and I can’t find
the article posted to HN a few months back which discusses it further. The
gist was wood protects itself with an insulating layer of charcoal as it
starts to burn, and it maintains its strength when heated much better than
steel, which starts to bend and cause a cascade failure.

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chadcmulligan
this one?
[https://news.ycombinator.com/item?id=20058485](https://news.ycombinator.com/item?id=20058485)

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nabla9
Modern glulam (glued laminated timber) and cross-laminated timber beams are
really good. Formaldehyde emissions are under control. Fire resistance is
surprisingly good. Economical and less energy needed for manufacturing.

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jazoom
Plus it sequesters carbon

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masklinn
Note that the Brock Commons mentioned in the article is a bit of a hybrid as
the structural core is a pair of concrete stairwells.

Norway's Mjøstårnet however (which took the palm from Brock) is structurally
fully wooden, concrete is only used as stabiliser for the upper stories
(inbetween the upper 7 stories to limit swaying), it's not load-bearing.

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voisin
Are you sure this is the structural core and not simply how they built the
fire exit and satisfied the municipality that the material for this fire exit
is non combustible? I doubt this is structural.

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brudgers
The reinforced concrete cores at Brock Commons are engineered to resist sheer
during earthquake and wind events. [1] BC is seismically active and every tall
buildings experiences non-trivial wind loads.

[1]:
[https://www.structuremag.org/?p=11624](https://www.structuremag.org/?p=11624)

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yvdriess
In Europe you will still find plenty of wood construction roadblocks. Personal
experience : in Belgium a wall that is placed on your terrain edge is
considered a common wall and cannot be made using wood.

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brudgers
That's generally true in the US as well. The placement of combustible walls
relative to property boundaries is constrained by building codes to mitigate
the spread of fire via radiant heat from fire on the adjacent
property/building.

Area separation wall systems [1] are about as close to "wood on the property
line" as is allowed. But technically the gypsum board is the wall between
structures (and for practical purposes both structures need to be built at the
same time).

[1]:
[http://www.usg.com/content/dam/USG_Marketing_Communications/...](http://www.usg.com/content/dam/USG_Marketing_Communications/united_states/product_promotional_materials/finished_assets/usg-
area-separation-walls-catalog-en-SA925.pdf)

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lnsp
I just hope they also go with green roofs. They make the microclimate within
cities just so much more sustainable.

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MindTooth
For someone who are knowledgeable about using wood for large buildings: how
does it stack against the weather?

I live a few miles from the largest in Norway[1], and if I recall, it's all
exposed. Perhaps some protection is added as of late. However, I also know
that using oil-based paint on the cladding increases the risk for rot if water
gets trapped inside. How do you need protect exposed wood for centuries to
come..

[1]:
[https://en.wikipedia.org/wiki/Mjøstårnet](https://en.wikipedia.org/wiki/Mjøstårnet)

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SiempreViernes
As I recall, you got some old wood buildings in Norway already, how are they
maintained?

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AngryData
A lot of traditional buildings around that area were/are treated with
wood/pine tar and charcoal, or by slightly burning the outside for a cheaper
and easier but less effective treatment.

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Fulvianus
Anybody knows what the sound insulation are like in these?

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voisin
Architects usually specify to include a sound dampening material on each
floor.

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krzat
I wonder if we could genetically modify the trees to be more construction
friendly.

It would be neat if you could plant a seed and it would automatically grow
into a house.

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winter_blue
What is the environmental impact of cutting down trees and constructing so
many buildings with wood?

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dougmwne
As long as the forests are replanted, likely benifit is carbon sequestration.
We should avoid logging old-growth forests since they provide ideal habitats
to deer and other animals. But logging second growth forests can be
environmentally sustainable.

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hak8or
How does this handle pests, like termites?

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garyrichardson
As a Vancouver local, I can't recall ever hearing about termite damage. I
don't know if we have them here. I've heard a few cases of carpenter ants
eating walls.

Woodpeckers can be a problem -- they will occasionally try to nest in the side
of a house. They also like to peck on metal siding. I think they do it to
attract mates?

