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.
Not a fire scientist, but solid blocks of dense dry hardwood are actually comparatively quite resistant to ignition. They are not completely fireproof, but superior to many other modern building materials and furnishings.
supposedly the safest thing to do if there is a fire on another floor is to shelter in place
Does it have sprinklers? Lack of sprinklers is what doomed the Marco Polo condominium victims despite all the mitigations.
"We've got three commercial fire hoses on every floor," he
said. "We've got three CO2 bottles, big ones, on every
floor. When we did the building originally, we thought we
have enough equipment at the time, so the fire will never
transfer to another unit. We have 45-minute fire doors, so
if we have a fire, we can keep it to one unit."
...
"Solid, concrete and pre-stressed -- it’s the best.” said
Schmidt. It was designed to accommodate natural, tradewind
ventilation, but he thinks those winds also helped to feed
the fire.
A piece of beech firewood lasts about 2-4 hours in a wood stove, which is pretty impressive methinks. (However, construction timber isn't hardwood and never beech).
Large solid timber beams actually burn incredibly slowly: partly because they're so dense, and because wood is a good insulator. For a similar thickness beam, wood takes much longer to fail than steel when superheated. At 1100F, steel starts turning into spaghetti. But on wood, the layer of carbon created by the char becomes an insulating barrier that reduces heat on the non-charred side by up to 90%.
A bigger concern to me is the wood rotting from exposure to water or chemicals. Although reinforced concrete also "rots", but in different ways. Wood at least tends to sag before failing from rotting, unlike concrete.
I'm kind of surprised they don't utilize things like steel torsion boxes for the foundations instead of concrete, but perhaps there's cost considerations. They could do a lot of fancy things to extend the size of wooden buildings using steel if they don't mind losing those fire retardant properties.
Also, it should be mentioned that wood-based buildings can re-ignite after an initial fire, which doesn't happen with steel or concrete. While you may escape the fire and the fire gets put out, the structure may still not be safe. We may need new fire codes if these buildings become commonplace.
"A bigger concern to me is the wood rotting from exposure to water or chemicals. Although reinforced concrete also "rots", but in different ways. Wood at least tends to sag before failing from rotting, unlike concrete."
This. We just moved our office into a 100+ year old wood building. We're doing the renovating ourselves. Most of the wood in the building is rotting or uneven. I've spent a week so far leveling the floors. Every old (70+ years old) building I've ever been in is like this; some worse than others.
We have our datacenter in a stone/concrete building that was built in 1912. While it has also deteriorated, it's not nearly as bad as the wooden buildings. The floors have cracks in them, but they're still level for the most part, or easily repairable. The building will easily be standing for another 200+ years. I can't say the same for the wood building.
You really don't know that about concrete buildings without inspection, and possibly core sampling of the concrete. You don't know what the true grade of the concrete is or whether it's thick enough depending on loading. And you need to look for signs of common failure modes such as carbonation, chloride penetration, freeze/thaw cycles, alkali-aggregate reactions, etc. Most concrete failures can penetrate the entire slab before showing outward signs. And concrete slabs have 'exploded' from as little as 200C of heat due to trapped water vapor. This assumes it's earthquake-code concrete construction.
A mostly-stone building will be perfectly fine, though :)
That is not a modern wooden building, however, i.e. not an apples to apples comparison to the subject of tfa. Cross laminated timber has a high resin (plastic?) content, which makes it a very different material from construction lumber in terms of how it interacts with moisture.
Timbers burn more slowly than intuition might suggest because the fire first chars the flame exposed surfaces and the charred surfaces no longer contain much fuel to feed further combustion. The likelihood of charring rather than combustion is increased by chamferring the corners of the members.
The problem with incorporating steel into wooden buildings is the difference in coefficients of expansion. Not just thermal but expansion when exposed to bulk water or merely humidity as well. The reason reinforced concrete works is the similar thermal expansion of concrete and steel and their negligible expansion from moisture and humidity.
The development of better engineering methods to deal with wood's expansion in the past two decades or so is one of the reasons tall wood buildings meeting contemporary construction requirements have become more practical and widespread.
Same here. I am going to offset the carbon thing in other ways, wooden buildings are just too dangerous. A 3 year with "mommy look how cool this is" can burn the house down in 3-4 minutes. Who has the FD right outside the house and ready to go 24/7?.
A concrete house on the other hand might need the plaster taken down and you're ready to re-plaster and move in. Or just clean and paint. Plus no squeaky stairs, ever :)
If that were true, wooden buildings would be more expensive to insure against fire damage than non-wooden ones. Turns out, a (properly designed and built) predominantly wooden building can get the same or (even better, depending on what it is compared against) ratings.
EDIT: adjusted wording to clarify re "wood framed"
That's at least figures family friends got for their buildings, not sure about the details. One thing I notice is that the top search results are about "wooden framed" - the house in question was predominantly wooden and thus more massive wood construction than just wood framing is.
If I think about it, I suspect this might not apply to larger buildings like those discussed in the article, (unless fixing partially damaged structures is easier? Don't know how the internal details work)
It all depends. Personally I don’t believe any claim like that unless the building is like new and above the local fire departments ladder reach.
I’ve been personally acquainted with about 10 building emergencies, including minor fires, and in 7/10 cases the facilities management made material errors in response and education that would kill many people in a more serious emergency. You should have zero trust in anything they say.
Seemingly innocuous changes to the building can dramatically reduce your chances of survival in a high rise fire. Bug out is always the best strategy, assuming there is adequate egress. If there isn’t adequate egress, don’t live there.
Solid wood burns very slowly, your choice of carpet and furniture will make a much bigger impact to making it out than the difference between wood and concrete beams.
Of course a wood building is more likely to be a total loss after a fire, so in terms of property damage it's a major consideration. In terms of loss of live, I doubt it makes a major difference as long as all wood has sufficient thickness.
I have lived in the US and in Europe. In the US, house fires are an almost everyday occurrence. In Europe, they happen much more rarely.
I would imagine that the interior decor is fairly on par in both places, and contributes similarly to the initial risk of fire.
It makes sense that major fires occur more often in the US than Europe, if you think about it. In the US, under the carpet or other flooring material you have wooden floorboards, with air spaces below them. This burns rather well. The structural elements are also made off wood. Once either of these catch on fire, poof.
In Europe, the immediate surface of the floor may be made of wood or another flammable material, but it is attached directly to the concrete substrate. This is much more difficult to burn.
The article did mention that this is pressed laminate wood which is treated not to burn, but rather char slowly. I hope that this type of construction is going to stand up to fire better than the current American wooden construction methods.
The vast majority of UK housing stock is also suspended wood flooring.
However there are vast differences in fire and electrical safety standards. There has been a concerted effort since the 80s to remove flammable sofas, carpets & mattresses. By luck rockwool was the insulation of choice for many years, unlike the states which either used spray foam or some other PE substance.
The standard of electrical safety in the US is comparable to 1960s Britain. (In the UK every plug & every socket _must_ have a fuse. effectively any electrical works demands that RCDs must be installed, which dramatically cut the risk of electrical fires. )
Note that fire safety and electrical standards are also very different in the US.
My impression has always been that you _can_ make a wood-framed house, at least, as fire safe as a brick or concrete one, but it's considerably easier for fire safety to be screwed up via improper construction or modifications.
Many if not most of 'fire' victims actually die due to burns to respiratory system due to hot smoke inhalation, suffocate via carbon dioxide displacing oxygen, get poisoned by carbon monoxide or cyanide compounds, etc.
Dying of burns is so hard that even some people who self immolate 'only' die days after or suffer life long impairment. It doesn't matter if the building doesn't burn because all the furniture in people flats will produce 'enough' heat and smoke in minutes, see: https://www.youtube.com/watch?v=0KSl9s6GjgY
Making sure your sprinklers are in working order seems like a good start. Also, based on the video I'd say "don't keep dry Christmas trees around." I dunno how they ignited that tree, but it went from fine to ceiling-high inferno in four seconds flat. I don't think typical furniture will catch nearly that fast in typical home-fire circumstances (overheated electrical devices, dropped cigarettes, etc). I wonder if keeping the tree in a watering stand and topping it up regularly helps.
Some Christmas trees are fake plastic ones, not real trees, I have no idea how they'd burn. I guess leaving one unattended with lights on it is always a bad idea.
I remember reading an article a while ago (https://www.usfa.fema.gov/downloads/pdf/statistics/v13i6.pdf not sure if it's still valid as it's from 2010), but a significant number of fatal house fires start in the bedroom due to dropped cigarettes... The report mentions that 2% of residential fires are smoking-related, and an average of 365 deals (i.e. in the United States, someone dies every day from setting their house on fire due to smoking!!). So clearly cigarettes can burn a house down pretty rapidly. I would assume, of course, that a substantial number of those deaths would have been people falling asleep and dropping the cig, which probably negates the speed of the fire spreading as being a factor.
Synthetic materials in furniture, carpet, clothing etc burns extremely rapidly as seen in the video. Not to mention that the tree looked to be very dry, and went up like dry grass would. In that situation, the radiated heat from that tree would be more than enough to rapidly set fire to the furniture around it.
An anecdote I can refer to myself is having dropped a cigarette in the car once, and having the entire rear bench-seat catch on fire within moments. (Car was moving at 100kph, so I assume the extra air forced into the environment didn't help!).
Have a big can of good brand fire extinguishing spray (it's smaller than a fire extinguisher and easier to use, not that fire extinguishers are hard to use, I used dry powder and carbon dioxide snow ones no problem during training) handy and don't leave electric lights unattended on Christmas trees I guess?
If you ever find yourself in a fire, get low. On all fours if you have to.
You should have at least two exists from your apartment. And when you are escaping fire, always open the doors very carefully. First like 5cm to see if there is any smoke coming from behind the door. And hold tight, because fires can suck/blow doors open with those huge air pressure variations.
And perhaps most importantly, do not let anybody to have anything flammable under the stairs in the common staircase. This is specifically against the fire code practically everywhere. But it's also common place for mothers to put their strollers.
Super interesting. I just outfitted my bedroom workshop with minimal first aid stuff (a wall mounted box with bandages and stuff as well as wall mounted eyewash bottles and a fire extinguisher)
I have been looking at respirators; I didn't get one 'cause my workshop isn't a chemistry lab, but I did look at them, and apparently one option is a bottle of compressed air with a valve so you can breath the compressed air.
The idea, of course, is that no matter how toxic whatever you released into the air was, if you were breathing this compressed air thing it wouldn't get into your lungs.
But... aside from avoiding the halon, I hadn't thought of it as something you would want in a fire and not just in a toxic gas situation, but from your description, it sounds like it'd really help you get out of the building.
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.
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.
Not that I'm telling anyone to rappel down a building, but there are at least four ways to rappel or lower yourself with just a rope and no gear (I highly recommend getting a professional to teach you first). But even so, most new apartments on high floors have aluminum ladders to deploy out a window.
It's strange when I hear about fires. I live in India and "fire" has never been a thing we thought of. It was rare to ever even see a fire brigade truck.
Maybe because most houses in India are made of brick?
According to statistics[0] you are about >5 times more likely to die in fire in India than pretty much any Western country. Just because you don't see it personally doesn't prove anything. What houses are made of are less relevant than finish and insulation materials used, furniture, carpets, type of heating, stove etc.
Yeah, fires are rare but deadly. Building codes for materials and escape routes, fire alarms and similar are preventive measures.
For instance, where I live there's a rule for houses that all rooms where people might sleep in must have a window big enough to allow a person to escape. Of course, unless you're interested in building a house, you'll never know about this rule.
It's a bit like a seatbelt or an airbag. How often have you actually needed those? Perhaps never. But the day an accident happens, it could easily save your life.
...Or just stop building high rises. It's always fascinating from an european PoV to see that in e.g. NY you have 60 floor housing buildings, and then close to them you have a sea of personal homes, each with a garden, large roads and no public transportation.
On the other hand, Paris is mostly 4-8 floor buildings and manages to have a better population density than the aggregate NY agglomeration.
I would assume that properly spaced 6-floor appartment blocks with two stairwells and a couple parks in the neighbourhood to evacuate to would reduce fire casualties dramatically, while also offering enough density for efficient transportation networks.
That building had defective/improperly specced modifications. It's extremely unusual for a high-rise fire to cause that sort of death and destruction. If everyone who currently lived in high-rises lived in houses, more cars would be required, and the extra road deaths would easily exceed the fire deaths...
This article doesn't mention it, but often when wood is used in 'modern' ways, it's laminated wood, and treated with fire-retardant materials. A contractor proposed a 'wooden' beam to me in one of my buildings a few years ago, in a place where traditionally it would have been steel, and the beam they ended up putting in looked like it was about equal amounts of wood and resin (that's an exaggeration of course - just saying, you could still recognize it as wood, but it's nothing like 'chop the sides off this log to square it and toss it in'; today's construction wood (in big(er) projects) in Europe isn't anything like 'building with wood' in the rest of the world).
Plus, a building that is framed with high-density wood beams is different (in terms of fire propagation properties) from an Anglo-Saxon style building of cheap (i.e., low density) timber 2x4's with sheet rock cladding.
Dude, CLT (cross laminated timber) is so dense it hardly chars. It's not the structure, it's what you hurbish it with that will cause the problems and this is a fact regardless of the material used for the structure (e.g. Grenfell towers disaster)
"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.
> Because tree farms are managed to enhance rapid growth, a tree farm tends to sequester carbon more quickly than an unmanaged forest, considering only the sequestration side of the equation and not the carbon release due to rot, fire, or harvest.[10] The fact that managed woodlands tend to be younger and younger trees grow faster and die less contributes to this distinction.[11]
> While tree farms absorb large amounts of CO2, the long-term sequestration of this carbon depends on what is done with the harvested materials. Forests continue to absorb atmospheric carbon for centuries if left undisturbed.
The CO2 captured by the tree when it grows is captured in the biomass; the wood itself chemically contains carbon, which stays trapped until the wood is burned. (cf the carbon-neutral cycle of biofuels.) Basically an organic form of carbon sequestration that happens to produce useful building materials.
The issue of replanting is addressed at the end of the article, when they talk about sustainability - specifically in the context of having enough forest space that wood can be grown fast enough to keep up with demand.
> Humans are notoriously bad at planning for the long term
Quite the opposite in fact. Humans are better than any other living things on the planet at planning over extremely long durations in relation to their life expectancy. Few other living things can even plan beyond a very, very short duration to begin with.
We do 20, 50, 100 year business & government agreements.
We build power grids that last decades or a century. We also frequently plot out power supply / generation for our grids that extend over many decades.
We put up buildings that last centuries.
We create water systems that last centuries.
We implement government structures and programs that last decades or centuries by design.
We create places of education, such as universities, that last centuries.
We frequently plant renewable forests that require planning over decades.
We regularly choose careers and life pathways (eg marriage, children) meant to last decades.
When it comes to this planet, we're extraordinary at long-term planning, even though we're also obviously not perfect at it.
It's possible to be simultaneously bad at something and still the best. I think the idea that we're bad at planning comes partly from the fact that we fail to meet our expectations very regularly.
Still we have less and less rainforests. Maybe some of us are good in planning, but the questions is what's in focus. Money or sustainability. I think nowadays it is still money.
Not true anymore, Most modern constructions don't last very long. And this is survivorship bias as well, since most of what remains from previous centuries is just what was strong enough to withstand time. The large majority has disappeared and you just don't see it.
> We implement government structures and programs that last decades or centuries by design.
Look at the political map 100 years ago vs now, nothing lasts for very long. Look at currencies 100 years ago and now, you'd be surprised how much has changed as well. Political systems are by far the most unstable ones of your examples. You'd be lucky to be in a country for you whole lifetime without a drastic political or economic change.
> We frequently plant renewable forests that require planning over decades.
Yet we don't take care very well of ancient forests that were there for hundreds of millenia before us. Look what's happening in South America.
> We regularly choose careers and life pathways (eg marriage, children) meant to last decades.
The rate of divorces, single-parent families in modern times seems to indicate we are pretty bad at making such choices. They are "meant" to last decades but they usually don't.
> When it comes to this planet, we're extraordinary at long-term planning
We have also found ways to completely destroy and pollute our environment in a very short time, while the footprint of other species is much lower than humans overall. Overfishing has emptied fishes from many seas around the world. Numerous species are disappearing as we destroy their habitat. That's certainly not the signs of "species that plan well".
>> We regularly choose careers and life pathways (eg marriage, children) meant to last decades.
> The rate of divorces, single-parent families in modern times seems to indicate we are pretty bad at making such choices. They are "meant" to last decades but they usually don't.
This is mostly a "don't want to", not a "can't". Being married "only" once in your life (or having children...) is apparently considered boring, old-fashioned and backwards by many.
If there's a need, we're able to plan ahead. For example:
"On Visingsö you find Europe's largest oak tree forest. The oaks were planted here by the Swedish government in the 1830s to be used by the navy's ship builders. When the oaks were ready for harvesting in 1975 they were offered to the navy, which declined to buy them."
Excuse my poor translation, full article in Swedish here:
I think I read old rainforests and the like are actually carbon neutral because of this. Since the biomass is already at peak capacity, the carbon release from decomposition is equal to the carbon sequestration from growth.
IIRC that was before wood eating molds evolved. After that biomass hasn't accumulated long term so much anymore.
We are eating spoils.
Bogs can be wet enough so you can have airless conditions for moss that becomes peat and maybe ultimately can become coal under pressure but it's a really really slow process.
Coal deposits took a long time to be created, so it's hard to tell if they are still being created.
Are forests net sequestering 1/1,000,000 of an inch per year of carbon? That would produce a lot of coal over the next 300 million years. Remember, roots can go 100+ feet underground.
Opinions differ on that point. I'm familiar with the lignan/rot hypothesis. Another view is that major coal beds, including those of Appalachia and Europe, formed in subducting marshes at the margins of a rising mountain range. Fossil evidence of decay suggests lignan-persistence alone wasn't sufficient to explain accumulations.
I don't know which model is more likely, just sharing the info.
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.
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.
Within a building envelope, if you have water or termite ingress you're already hosed and a layer of paint or gypsum isn't going to save you.
The cross-laminated timbers aren't going to be the first thing to rot. In a traditional wood framed building you're looking at the sill plates, the sheathing, perhaps the end of the joists. The high-rise construction shown in the article seems to avoid most of that - the SIPs don't appear to use much wood except the facade.
We just moved into our new office space in what is supposedly the largest timber office building in the US [0]. In the interior, nearly all the wood is exposed and it looks really cool.
The outside of the building is sheathed in some sort of metal, I presume to protect the wood, but they even did a good job of making the metal look cool too.
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.
"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."
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.
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.
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.
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).
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.
> one acre of managed forest can produce about thirty square meters of the 20-inch-thick panels mentioned in the article per year.
> I'll guess it takes around four of those acre-year units to build one person's worth of an apartment building.
France has about 30 million acres of privately held forest. Let's assume that half of this surface produces at your estimated rate, and 20% of that production goes to building: that would be about 3 million acres or 750.000 new individual units per year. With about 775-800k births in recent years, this would be fine.
"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.
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.
By the way, is it the same with high rise, glass towers? I live in a mid size (20 floors) modern-ish building (1999) with excellent acoustic insulation (as in spotless, never heard a whisper from a neighbor). But the building is made of concrete with some windows. I am comparing that to high rise towers (50-60 floors) where you only have a thin layer of concrete between floors but no concrete between apartments (probably to keep the weight down). Wouldn't you expect these towers to have structurally poor acoustic insulation?
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.
Surprisingly, wood construction never really stopped improving and even picked up in the past decade or two. A renovation would not touch the core construction or noise. In order to make it even a little quieter you'd have to rip up the floor down to the joists and install a new subfloor.
Innovations like engineered lumber, PEX and high R insulation have made a world of difference since my habitat for humanity days.
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.
There are a half dozen ways to silence a squeaky floor. Nobody does them because it's an expense and hassle and they don't mind the noise.
The more difficult problem, reverberation and sound travel, is really a simple acoustics problem. If you have something that makes noise and there is nothing but a big gaping box with flat sides for it to reverberate in, then you're going to hear stuff.
Often the simplest solution is to install carpeting. But if a tenant prefers wood floor, you can install sound-deadening insulation between the subfloor and finished floor, or subfloor and lower ceiling.
How 'modern' are we talking about? In the mid to late '00s I lived in a new, wood apartment building and the noise was unbearable. You could hear doors slamming from below and people walking around above you.
It depends a lot on where you are. Warm parts of the US will build houses with 2x4s and uninsulated interior walls+floors. In the northern US the exterior and even sometimes interior walls are 2x6 and have high quality insulation in the walls, floors and ceilings, plus nowadays there's quite a thick layer of foam on the outside. The extra strength and rigidity does a ton of work attenuating noise from other parts of the house, and the walls are much harder to transmit sound through.
GP poster lives in Switzerland. US construction quality is weak, and building code would be nice to have. It may come as a surprise to those who have never been to the States to see just how awful housing in America is, on the contrary, those in America who have never been to Europe will be surprised to see how nice a multifamily building can be when it's properly constructed.
What?? Surely you can come up with a better example than a house built on a collapsing cliff that was intentionally burned down.
Edit: your comment would be more helpful if it referenced improved construction techniques and materials that are commonly used in Europe that haven't been adopted in the US.
The point is that even at that price point it's still wood frame and sheetrock. It's just fancier finishings, but nothing like the anhydrite floor with soundproofing layer that decouples the floor from the rest of the building that someone further up had mentioned.
I live in a wooden house. It isn't the wood that is the problem but the way it is used. My house is in Norway and was built in 1950. The floorboards are tongued and grooved pine about three inches wide and two inches thick. Unless someone is wearing shoes upstairs I hardly hear a thing. Of course in a building occupied by multiple groups I wouldn't be able to enforce the no shoes indoors rule. But I swore i would never live in the same building as another family ever again after enduring two years of loud record playing from below but that was in a concrete building.
Keep in mind this is not wood as in trees cut to parts. These buildings almost always use CLT - cross laminated timber. So there are no air gaps to speak of.
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.
"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.
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?
Trees only capture CO2 while they grow. If you cut down mature tree and let another tree grow, while you store its carbon in constructions, you are effectively creating a carbon capture process.
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[ 3.9 ms ] story [ 217 ms ] threadOur 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&...)
supposedly the safest thing to do if there is a fire on another floor is to shelter in place
Of course, that's what they said about Grenfell.
A bigger concern to me is the wood rotting from exposure to water or chemicals. Although reinforced concrete also "rots", but in different ways. Wood at least tends to sag before failing from rotting, unlike concrete.
I'm kind of surprised they don't utilize things like steel torsion boxes for the foundations instead of concrete, but perhaps there's cost considerations. They could do a lot of fancy things to extend the size of wooden buildings using steel if they don't mind losing those fire retardant properties.
Also, it should be mentioned that wood-based buildings can re-ignite after an initial fire, which doesn't happen with steel or concrete. While you may escape the fire and the fire gets put out, the structure may still not be safe. We may need new fire codes if these buildings become commonplace.
This. We just moved our office into a 100+ year old wood building. We're doing the renovating ourselves. Most of the wood in the building is rotting or uneven. I've spent a week so far leveling the floors. Every old (70+ years old) building I've ever been in is like this; some worse than others.
We have our datacenter in a stone/concrete building that was built in 1912. While it has also deteriorated, it's not nearly as bad as the wooden buildings. The floors have cracks in them, but they're still level for the most part, or easily repairable. The building will easily be standing for another 200+ years. I can't say the same for the wood building.
A mostly-stone building will be perfectly fine, though :)
The problem with incorporating steel into wooden buildings is the difference in coefficients of expansion. Not just thermal but expansion when exposed to bulk water or merely humidity as well. The reason reinforced concrete works is the similar thermal expansion of concrete and steel and their negligible expansion from moisture and humidity.
The development of better engineering methods to deal with wood's expansion in the past two decades or so is one of the reasons tall wood buildings meeting contemporary construction requirements have become more practical and widespread.
A concrete house on the other hand might need the plaster taken down and you're ready to re-plaster and move in. Or just clean and paint. Plus no squeaky stairs, ever :)
EDIT: adjusted wording to clarify re "wood framed"
If I think about it, I suspect this might not apply to larger buildings like those discussed in the article, (unless fixing partially damaged structures is easier? Don't know how the internal details work)
I’ve been personally acquainted with about 10 building emergencies, including minor fires, and in 7/10 cases the facilities management made material errors in response and education that would kill many people in a more serious emergency. You should have zero trust in anything they say.
Seemingly innocuous changes to the building can dramatically reduce your chances of survival in a high rise fire. Bug out is always the best strategy, assuming there is adequate egress. If there isn’t adequate egress, don’t live there.
Of course a wood building is more likely to be a total loss after a fire, so in terms of property damage it's a major consideration. In terms of loss of live, I doubt it makes a major difference as long as all wood has sufficient thickness.
I would imagine that the interior decor is fairly on par in both places, and contributes similarly to the initial risk of fire.
It makes sense that major fires occur more often in the US than Europe, if you think about it. In the US, under the carpet or other flooring material you have wooden floorboards, with air spaces below them. This burns rather well. The structural elements are also made off wood. Once either of these catch on fire, poof.
In Europe, the immediate surface of the floor may be made of wood or another flammable material, but it is attached directly to the concrete substrate. This is much more difficult to burn.
The article did mention that this is pressed laminate wood which is treated not to burn, but rather char slowly. I hope that this type of construction is going to stand up to fire better than the current American wooden construction methods.
However there are vast differences in fire and electrical safety standards. There has been a concerted effort since the 80s to remove flammable sofas, carpets & mattresses. By luck rockwool was the insulation of choice for many years, unlike the states which either used spray foam or some other PE substance.
The standard of electrical safety in the US is comparable to 1960s Britain. (In the UK every plug & every socket _must_ have a fuse. effectively any electrical works demands that RCDs must be installed, which dramatically cut the risk of electrical fires. )
My impression has always been that you _can_ make a wood-framed house, at least, as fire safe as a brick or concrete one, but it's considerably easier for fire safety to be screwed up via improper construction or modifications.
Dying of burns is so hard that even some people who self immolate 'only' die days after or suffer life long impairment. It doesn't matter if the building doesn't burn because all the furniture in people flats will produce 'enough' heat and smoke in minutes, see: https://www.youtube.com/watch?v=0KSl9s6GjgY
Though, not sure what "Needle moisture content > 100%" means. That it's transpiring?
I remember reading an article a while ago (https://www.usfa.fema.gov/downloads/pdf/statistics/v13i6.pdf not sure if it's still valid as it's from 2010), but a significant number of fatal house fires start in the bedroom due to dropped cigarettes... The report mentions that 2% of residential fires are smoking-related, and an average of 365 deals (i.e. in the United States, someone dies every day from setting their house on fire due to smoking!!). So clearly cigarettes can burn a house down pretty rapidly. I would assume, of course, that a substantial number of those deaths would have been people falling asleep and dropping the cig, which probably negates the speed of the fire spreading as being a factor.
Synthetic materials in furniture, carpet, clothing etc burns extremely rapidly as seen in the video. Not to mention that the tree looked to be very dry, and went up like dry grass would. In that situation, the radiated heat from that tree would be more than enough to rapidly set fire to the furniture around it.
An anecdote I can refer to myself is having dropped a cigarette in the car once, and having the entire rear bench-seat catch on fire within moments. (Car was moving at 100kph, so I assume the extra air forced into the environment didn't help!).
IIRC a lot of the dropped cigarette fire deaths are also related to alcohol consumption.
For more horror (and to become scared of windows and doors during a fire) see: https://en.wikipedia.org/wiki/Backdraft
You should have at least two exists from your apartment. And when you are escaping fire, always open the doors very carefully. First like 5cm to see if there is any smoke coming from behind the door. And hold tight, because fires can suck/blow doors open with those huge air pressure variations.
And perhaps most importantly, do not let anybody to have anything flammable under the stairs in the common staircase. This is specifically against the fire code practically everywhere. But it's also common place for mothers to put their strollers.
Even before doing that, touch the door/handle with the back of your hand to see if it's hot.
I have been looking at respirators; I didn't get one 'cause my workshop isn't a chemistry lab, but I did look at them, and apparently one option is a bottle of compressed air with a valve so you can breath the compressed air.
The idea, of course, is that no matter how toxic whatever you released into the air was, if you were breathing this compressed air thing it wouldn't get into your lungs.
But... aside from avoiding the halon, I hadn't thought of it as something you would want in a fire and not just in a toxic gas situation, but from your description, it sounds like it'd really help you get out of the 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?
But yes I suppose technically you can have rollers in vertical struts and have them roll down inside the rails, carrying the person.
It makes sense to keep a fire axe in your apartment, so you can make your own doorways/windows as needed in a fire. Also good against zombie attacks.
Fire axes are designed specifically for that sort of job.
Maybe because most houses in India are made of brick?
0. http://www.worldlifeexpectancy.com/cause-of-death/fires/by-c...
For instance, where I live there's a rule for houses that all rooms where people might sleep in must have a window big enough to allow a person to escape. Of course, unless you're interested in building a house, you'll never know about this rule.
It's a bit like a seatbelt or an airbag. How often have you actually needed those? Perhaps never. But the day an accident happens, it could easily save your life.
On the other hand, Paris is mostly 4-8 floor buildings and manages to have a better population density than the aggregate NY agglomeration.
I would assume that properly spaced 6-floor appartment blocks with two stairwells and a couple parks in the neighbourhood to evacuate to would reduce fire casualties dramatically, while also offering enough density for efficient transportation networks.
Plus, a building that is framed with high-density wood beams is different (in terms of fire propagation properties) from an Anglo-Saxon style building of cheap (i.e., low density) timber 2x4's with sheet rock cladding.
https://en.m.wikipedia.org/wiki/Grenfell_Tower_fire
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.
> Because tree farms are managed to enhance rapid growth, a tree farm tends to sequester carbon more quickly than an unmanaged forest, considering only the sequestration side of the equation and not the carbon release due to rot, fire, or harvest.[10] The fact that managed woodlands tend to be younger and younger trees grow faster and die less contributes to this distinction.[11]
> While tree farms absorb large amounts of CO2, the long-term sequestration of this carbon depends on what is done with the harvested materials. Forests continue to absorb atmospheric carbon for centuries if left undisturbed.
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...
The issue of replanting is addressed at the end of the article, when they talk about sustainability - specifically in the context of having enough forest space that wood can be grown fast enough to keep up with demand.
Problem is two-fold:
- Trees take quite a long time to grow
- Humans are notoriously bad at planning for the long term
What could go wrong? If the demands picks up the most likely outcome is an increased pace of deforestation.
Quite the opposite in fact. Humans are better than any other living things on the planet at planning over extremely long durations in relation to their life expectancy. Few other living things can even plan beyond a very, very short duration to begin with.
We do 20, 50, 100 year business & government agreements.
We build power grids that last decades or a century. We also frequently plot out power supply / generation for our grids that extend over many decades.
We put up buildings that last centuries.
We create water systems that last centuries.
We implement government structures and programs that last decades or centuries by design.
We create places of education, such as universities, that last centuries.
We frequently plant renewable forests that require planning over decades.
We regularly choose careers and life pathways (eg marriage, children) meant to last decades.
When it comes to this planet, we're extraordinary at long-term planning, even though we're also obviously not perfect at it.
> We put up buildings that last centuries.
Not true anymore, Most modern constructions don't last very long. And this is survivorship bias as well, since most of what remains from previous centuries is just what was strong enough to withstand time. The large majority has disappeared and you just don't see it.
> We implement government structures and programs that last decades or centuries by design.
Look at the political map 100 years ago vs now, nothing lasts for very long. Look at currencies 100 years ago and now, you'd be surprised how much has changed as well. Political systems are by far the most unstable ones of your examples. You'd be lucky to be in a country for you whole lifetime without a drastic political or economic change.
> We frequently plant renewable forests that require planning over decades.
Yet we don't take care very well of ancient forests that were there for hundreds of millenia before us. Look what's happening in South America.
> We regularly choose careers and life pathways (eg marriage, children) meant to last decades.
The rate of divorces, single-parent families in modern times seems to indicate we are pretty bad at making such choices. They are "meant" to last decades but they usually don't.
> When it comes to this planet, we're extraordinary at long-term planning
We have also found ways to completely destroy and pollute our environment in a very short time, while the footprint of other species is much lower than humans overall. Overfishing has emptied fishes from many seas around the world. Numerous species are disappearing as we destroy their habitat. That's certainly not the signs of "species that plan well".
> The rate of divorces, single-parent families in modern times seems to indicate we are pretty bad at making such choices. They are "meant" to last decades but they usually don't.
This is mostly a "don't want to", not a "can't". Being married "only" once in your life (or having children...) is apparently considered boring, old-fashioned and backwards by many.
"On Visingsö you find Europe's largest oak tree forest. The oaks were planted here by the Swedish government in the 1830s to be used by the navy's ship builders. When the oaks were ready for harvesting in 1975 they were offered to the navy, which declined to buy them."
Excuse my poor translation, full article in Swedish here:
https://www.sydved.se/skogsagarliv/fran-vara-skogar/ekarna-s...
That said I agree that your basic argument sounds reasonable.
That might often be a good sign I think :-)
We are eating spoils.
Bogs can be wet enough so you can have airless conditions for moss that becomes peat and maybe ultimately can become coal under pressure but it's a really really slow process.
Are forests net sequestering 1/1,000,000 of an inch per year of carbon? That would produce a lot of coal over the next 300 million years. Remember, roots can go 100+ feet underground.
I don't know which model is more likely, just sharing the info.
http://www.pnas.org/content/early/2016/01/13/1517943113
https://www.economist.com/news/science-and-technology/216887...
There were molds that could digest lignin in that period. Furthermore, most of the plant mass didn't depend on lignin.
See http://phenomena.nationalgeographic.com/2016/04/06/getting-t...
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.
The cross-laminated timbers aren't going to be the first thing to rot. In a traditional wood framed building you're looking at the sill plates, the sheathing, perhaps the end of the joists. The high-rise construction shown in the article seems to avoid most of that - the SIPs don't appear to use much wood except the facade.
The outside of the building is sheathed in some sort of metal, I presume to protect the wood, but they even did a good job of making the metal look cool too.
[0]: http://www.t3northloop.com/
Do you have any pictures to share? I saw a bunch of them on the site but they all look like professionally photographed glamour shots.
What does it actually look like?
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...
Bringing awareness is still a good thing of course. Which is how I tend to see most of these projects.
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).
> I'll guess it takes around four of those acre-year units to build one person's worth of an apartment building.
France has about 30 million acres of privately held forest. Let's assume that half of this surface produces at your estimated rate, and 20% of that production goes to building: that would be about 3 million acres or 750.000 new individual units per year. With about 775-800k births in recent years, this would be fine.
Only when the kids upstairs are _really_ wild you can hear their steps.
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.
I'd guess around 20 (-ish).
Innovations like engineered lumber, PEX and high R insulation have made a world of difference since my habitat for humanity days.
Note how the parent said "modern wooden house" (though that also implies "expensively-ish insulated" I think).
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.
The more difficult problem, reverberation and sound travel, is really a simple acoustics problem. If you have something that makes noise and there is nothing but a big gaping box with flat sides for it to reverberate in, then you're going to hear stuff.
Often the simplest solution is to install carpeting. But if a tenant prefers wood floor, you can install sound-deadening insulation between the subfloor and finished floor, or subfloor and lower ceiling.
This one is emblematic of US construction: https://www.nbcdfw.com/news/local/Lake-Whitney-Cliff-House-M...
Edit: your comment would be more helpful if it referenced improved construction techniques and materials that are commonly used in Europe that haven't been adopted in the US.
https://en.wikipedia.org/wiki/Minergie
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.
Trees only capture CO2 while they grow. If you cut down mature tree and let another tree grow, while you store its carbon in constructions, you are effectively creating a carbon capture process.
I would think something like aerocrete would also provide superior insulation.
If you plant a tree farm and use the wood to create buildings you are effectively doing carbon sequestration.