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Comment by oaijdsfoaijsf | Hacker News Reader

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&...)

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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.

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

Bloody hell that is terrifying! Short of having a barren apartment, is there anything you can do to guard against this?

A wet cloth over the mouth/nose will catch a lot of the particulates and water-soluble vapors, though it won't help a lot with the heat.

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.

Looks like it: https://www.fema.gov/media-library/assets/videos/76417

Though, not sure what "Needle moisture content > 100%" means. That it's transpiring?

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.

> dropped cigarettes, etc

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!).

It literally said that this is a video of 'dry scotch pine tree fire' at the start, wet things of course don't burn as easily.

Another common way to die in a fire is to come home drunk from the bar, decide you're hungry and put something in the oven/stove, then pass out.

IIRC a lot of the dropped cigarette fire deaths are also related to alcohol consumption.

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?

For more horror (and to become scared of windows and doors during a fire) see: https://en.wikipedia.org/wiki/Backdraft

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.

>First like 5cm to see if there is any smoke coming from behind the door.

Even before doing that, touch the door/handle with the back of your hand to see if it's hot.

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.

Do the magnets wear out over time though?

or if you've lost too much weight or there is crap on the magnet and less friction, and suddenly your stuck in the air pasted to a burning building xD

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

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.

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.

What happens when the fire is on a lower floor and melts/burns your rope because the fire is going out the window?

Go out a different window.

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.

In a large high-rise, the majority of apartments will only have windows on one side (unless there's an inner core or something).

I wasn't clear about what to do with the fire axe - go into the hall, and cut through the door to an apartment on another side.

Fire axes are designed specifically for that sort of job.

There have been many other fires in England where the building hadn't been illegally modified and the firebreaks worked as intended.

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.

0. http://www.worldlifeexpectancy.com/cause-of-death/fires/by-c...

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.

You'll need a rope bag, otherwise your rope will burn, and also the weight will lock your figure 8

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.

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

Of course, that's what they said about Grenfell.

Fortunately, my building still has the original brick cladding.

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.

-- http://www.kitv.com/story/35948583/long-time-marco-polo-resi...

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).

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)

Aye that cladding is so important. Really terrible that the older building would have been less flammable before shoddy renovations.

https://en.m.wikipedia.org/wiki/Grenfell_Tower_fire

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"

they cost the same? https://www.google.com/search?q=fire+insurance+wooden+vs+con...

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)

This article isn't talking about what American's (and Australians, and Canadians, and Brits) consider 'wood buildings'. Apples and oranges.

It's still wood, granted full of glues and chemicals.

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