
Why Timber Towers Are on the Rise in France - jseliger
https://www.citylab.com/design/2017/10/why-timber-towers-are-on-the-rise-in-france/544098/
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tschwimmer
Something I'm surprised that nobody's mentioned yet are the acoustics of a
wooden building. Wood is less dense when compared to concrete and (at least in
older buildings) there are significant air gaps between ceiling and
floorboards of the floor above it. As anyone who's lived in an SF Victorian
will tell you even regular walking can be perceived as loud by the person
below. Before I'd consider living in a wooden building, I'd have to be
convinced that the noise isolation would be sufficient. I wonder if it's been
accounted for properly in these new buildings.

~~~
cstuder
As someone living in a modern wood building I can tell you that this is really
not a problem anymore. Our floors are filled with anhydrite, they are solid.

Only when the kids upstairs are _really_ wild you can hear their steps.

~~~
boobsbr
As someone living in a wooden house, I can say it's still problem.

Even walking barefooted upstairs can be heard from downstairs. Floorboards
creak and make noise.

Only places that don't make this noise are the bathroom and kitchen, which
have tiled concrete floors.

~~~
zip1234
Creaking floorboards can be solved by attaching the floors more securely. Just
screw them down. Usually it is caused by wood moving against nails.

~~~
rsync
Correct. Most squeaky wood floors and stairways, etc., were just assembled
poorly and you can actually fix them _in situ_ with finish screws. I recommend
the #8 GRK finish screws @ 2.5 inch length.

Either find your biggest (heaviest) friend to stand on the spot before you
insert the screw OR find a way to jam the floor down from the ceiling. You
lock the floorboard in place, fully compressed, and then seal it in place with
the screw(s).

For new wooden floors, I highly recommend a layer of cork between the
floorboards and subfloor for a variety of reasons ... insulation, noise,
squeak avoidance, etc. I would not build a wooden floor without that layer.

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thisisit
"The production of cement, one of the main ingredients in concrete, generates
an estimated 5 percent of the world’s carbon emissions. Trees, in contrast,
capture CO2, helping offset emissions produced by a typical building process."

If I am reading this correctly it's the trees and not timber, laminated or
otherwise, which capture CO2. So what kind of advantage does timber offer in
form of CO2 emission? Specially considering the tree is now gone and this
article doesn't cover if there is re-plantation - something like sow a 5
plants of each tree used for timber.

~~~
nostoc
Timber is carbon that a tree has pulled from the atmosphere.

As long as it stays in a building, it's not going back in the atmosphere.

Planting trees and turning them into timber is a form of carbon sequestration.
As long as it doesn't burn or decay...

~~~
Neil44
It’s interesting, you could say that trees grow out of the air, not the
ground.

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kijin
Indeed, most of the mass of a tree comes from the air. Even the water was in
the air not so long ago.

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teekert
Perhaps it's difficult to convey but I redid a lot of the interior of my
current (brick and mortar) home from the 1930's myself and it really made me
appreciate wood as a building material. Strong, very easily made into the
required shape, easy to attach to each other, easy to attach other things
to... I always felt wood was "how we used to do it"... not anymore.

Guess this place is a good as any to express my found love for the material.

~~~
rsync
"Guess this place is a good as any to express my found love for the material."

I agree with you but I would point out that the buildings and their "wood"
materials that the article discusses are really not anything like what you
worked with.

The article speaks about wood and trees and "timbers" but these building
materials are engineered panels and timbers that, while in many cases
_actually stronger_ than their "real wood" counterparts, do not have the
aesthetics you remember.

I would go so far as to suggest that they are moving not from concrete to wood
construction, but from concrete to _glue_ construction.

~~~
teekert
Ah, good clarification, indeed I mostly used pinewood for inside and Azobe and
Meranti for outside (though some composite for the parts we walk on). But The
pleasure was mostly from being able to drills holes and put screws in with a
light cordless drill and saw it in the right shape either by hand or a light
jig saw. It's carry-able and still very strong. I guess this also applies to
the used composite materials your describe?

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oaijdsfoaijsf
Wood is a very cool material! But I would be nervous living in a tall building
made out of it, because of its flammability. Maybe if all the wood buildings
also have sprinkler systems, that would offset the risks.

Our building is a concrete building about fourteen stories tall. The
information we received as part of the lease tells us that it's known as a
non-flammable building, and supposedly the safest thing to do if there is a
fire on another floor is to shelter in place. I doubt the same would be true
in any wood building.

Oh, and apparently the article also speaks to this:

> It’s also this heft that helps make CLT fire-resistant: the outside layers
> char slowly, protecting the wood inside from burning.

(More on that:
[https://www.youtube.com/watch?list=UUGNoTP0Nlc1O-EWf3d1m3QQ&...](https://www.youtube.com/watch?list=UUGNoTP0Nlc1O-EWf3d1m3QQ&time_continue=36&v=hRIPQ_q2iyY))

~~~
SCAQTony
After that terrible fire in England I would recommend getting a 150-meter
climbing rope, a harness and an aluminum "figure-eight" and learn how to repel
as a means of escape in case the smoke became far too overwhelming. But that's
just me. I live in a house.

~~~
EGreg
I had an invention that could help many people escape from a building:

Magnetic strips on the side of the building, and backpacks with metal.

You put on the backpack and shimmy down. Just in case, you also strap yourself
onto the slide by its sides, so as not to disconnect from it and fall off.

This is better than a rope because it can hold many people simultaneously.

Do the magnets wear out over time though?

~~~
vlehto
Magnets are probably way too expensive. Especially as you could get same
functionality with regular fire ladder.

~~~
EGreg
How would you shimmy down the ladder?

But yes I suppose technically you can have rollers in vertical struts and have
them roll down inside the rails, carrying the person.

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bastijn
So how much of earth do we need to cover with forest to have a sustainable
production for our buildings at a level that it actually matters? One building
works, sure enough. But is it scalable to a level that it actually helps? I
have my doubts.

Bringing awareness is still a good thing of course. Which is how I tend to see
most of these projects.

~~~
jtolmar
If I did all my math/googling right, one acre of managed forest can produce
about thirty square meters of the 20-inch-thick panels mentioned in the
article per year. (A typical wood weighing 0.4 tons per square meter and a
managed forest producing about 6 tons per acre per year.)

I'll guess it takes around four of those acre-year units to build one person's
worth of an apartment building. (Thirty square meters is on the small side for
an apartment, and apartments need walls, but they're also not going to be
entirely constructed of the thickest panels.)

My home city of Seattle is growing at about 20k people per year, which (if we
try to fit them all in wooden highrises) works out to 80k acres, which is
roughly the size of the city itself. I feel like that'd be entirely
reasonable.

It's also worth noting that this sequesters a rather appreciable amount of
carbon (trees are half carbon, so about 240 kilotons per year).

~~~
mseebach
Also, if we're considering ecological foot print, structural use of wood is
near-permanent sequestering (ie. carbon-negative) which is better than most
other uses of wood such as burning for fuel which is "only" carbon-neutral.

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bcn
Here are a few renderings of the "Arboretum" project that was mentioned in the
article-
[http://www.laisneroussel.com/fr/projects/55](http://www.laisneroussel.com/fr/projects/55)

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frik
"Timber Towers" work for up to about 10-story building (depending on
architecture, building technique). It's similar to brick and mortar buildings,
only with the introduction of cement and steel we got the first high rise
skyscrapers (1890s-1930s). Also fire-safety (30+ min fire resistance) is a
problem with wood based buildings, the photos shows that at least the elevator
and staircase shaft is made out of steel reinforced concrete. That said wood
based buildings have a warmer in-house climate and other positive aspects.

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robbrown451
There is something bothersome to me about using all that wood only to cover it
up. Concrete is ugly and wood is beautiful, in my opinion. I hope they leave a
lot of the wood visible.

~~~
virmundi
As a person replacing a 130 year old sill plate, cover up structural wood.
Termites and water can destroy it.

~~~
wahern
If it's covered, how can you tell when there's damage?

We recently had seismic plywood shear walls installed in our soft story
garage, holding up our 2 stories of living space. A previous owner actually
had shear walls installed in 1992, after the 1989 Loma Prieta earthquake. But
the '92 retrofit used the wrong grade of plywood, and used screws instead of
nails. Screws have poor shear strength. The panels were basically useless for
seismic safety and had to be replaced.

The 90-year-old redwood studs looked surprisingly pristine. But one of the
studs had some kind of termite or fungal damage. The entire stud, top to
bottom, basically disintegrated in your hands; but everything else was in
perfect shape, including the sills. There were no outward signs of this at all
--neither on the stud itself, on adjacent studs, nor the top or bottom sill
plates. It was bizarre. And it would have gone totally unnoticed and maybe
even spread, completely undetected, had the old panels not been removed.

The shear walls weren't the only things improperly installed. The 1992
foundation bolts didn't use adequately sized washers, so with enough movement
the bolt heads would have ripped through the sill plate. Again, this was
hidden behind the wall panels.

I grew up in Florida trailer parks. To me anything covered is hiding something
--cockroaches, termites, substandard construction. Were there no need for the
shear walls, I'd much prefer to have exposed studs and a completely exposed
sill plate, at least in the garage.

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MrFantastic
Concrete buildings can last for centuries. There are few wood buildings that
last that long.

I would think something like aerocrete would also provide superior insulation.

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jasonmaydie
How is cutting down trees better for climate change? Don't we need more trees?

~~~
johngalt
Think of trees as co2 batteries. They take in co2 to create wood then release
it back when they burn or decay.

If you plant a tree farm and use the wood to create buildings you are
effectively doing carbon sequestration.

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EGreg
What about the risk of fire, as they had in Chicago and London etc.

~~~
rsynnott
Assuming you're talking about Grenfell, that was an old concrete building. The
fire was so deadly due to improperly specced and/or installed exterior
cladding which had recently been added; nothing to do with wood.

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eksemplar
Is the clue and fire resistance safe to breathe though?

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anovikov
It's rather stupid to worry about global warming here, as concrete use in
France is less than 1% of what it is in China anyway.

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Animats
This trend towards large multi-story timber apartment buildings is worrying.
That used to be prohibited in many US jurisdictions. Now I see San Jose and
Redwood City putting up lots of these things. "Luxury apartments" made of
chipboard. The fire protection people aren't happy about this.[1]

There's a fad for "podium buildings". The first two floors are steel and
concrete, and then there are a few floors of wood. These appear in areas where
you're not allowed wood construction for commercial buildings. The bottom
floors are commercial; the upper floors are residential.

[1] [https://community.nfpa.org/community/nfpa-
today/blog/2017/03...](https://community.nfpa.org/community/nfpa-
today/blog/2017/03/21/recent-fires-in-apartment-buildings-under-construction-
highlight-the-importance-of-developing-a-fire-safety-program-and-designating-
a-fire-prevention-manager-during-construction)

~~~
jkaljundi
Modern wood is much more fire resistant than concrete or steel
[https://www.youtube.com/watch?v=t-3oEb8KUiQ](https://www.youtube.com/watch?v=t-3oEb8KUiQ)
\- it's an imaginary myth, that wood is dangerous.

~~~
scythe
Wood constructed buildings are fire resistant. The article he linked discusses
fires in buildings under construction recently. All wood is flammable, but
insulation goes a long way.

