To demonstrate mass timber’s fire resistance, engineers put the wood elements in gas-fired chambers and monitor their integrity. Other tests set fire to mock-ups of mass timber buildings and record the results.
These tests have gradually convinced regulators and customers that mass timber can resist burning long enough to be fire safe. That’s partly because a layer of char tends to form early on the outside of the timber, insulating the interior from much of the fire’s heat.
I live in a country where single family homes are built with wood. Everyone seems to trust their life to that. I don’t know why it would be different in an apartment.
Because these are literal sky scrapers. Fire on a wood structure is a recipe for catastrophic failure. A fire in a large structure could have similar effects to those large high rise condos that collapsed in Florida from poor maintenance.
This is very likely dangerous deregulation of the fire code to cut costs being “green washed” as a new thing that needs a hell of a lot more scrutiny. Building large structures with wood WAS a thing in the past, it was outlawed because it’s EXTREMELY dangerous when one of those structures ignites.
They’re only getting away with it because these are composite timbers which have been “tested” to be safer. I’m very skeptical that those tests are comprehensive, at least to the point where I would feel comfortable spending a significant portion of my life in one of these buildings.
Because these are literal sky scrapers. Fire on a wood structure is a recipe for catastrophic failure. A fire in a large structure could have similar effects to those large high rise condos that collapsed in Florida from poor maintenance.
i think you’re operating under 1) an extremely 1800s understanding of how fire-resistant a wood skyscraper would be and 2) a misguided understanding of where fire safety problems tend to come from in most contemporary buildings
wood is not uniquely flammable,[1] and the vast majority of the problem in a fire is not going to be with the actual wood itself (as is true of steel, concrete, etc.) but moreso with the fact that we make nearly everything that isn’t the building itself out of extremely combustible materials and we probably should not do that? as i recall that was the entire problem at Grenfell, where the cladding used was a flammable plastic that rendered any airgapping measures between flats useless and allowed the fire to spread uncontrollably. the fire at Grenfell also reportedly began from a refrigerator that was plastic-backed.
it can rather trivially be treated to be fire-resistant–and as the person you’re replying to notes has already been tested extensively and implemented in existing buildings to that end, and in multiple locales, just from a brief search on the subject ↩︎
We’re also living in an era where regulator bodies have been repeatedly weakened by large companies and interest groups.
Does that fire resistance hold up over a decade, two decades, a century, etc? Even if internationally regulatory bodies are 100% in good hands … there’s no way everybody is using the same blend of wood + fire retardant.
Also how realistic are the laboratory conditions? Do the same testing rules apply if an accelerate has been used to increase the burn rate?
What about the human impact? What’s the impact of inhaling smoke off of these? Environmental impact from the gasses inevitably produced?
How repairable is the timber structure in case of fire?
These questions have pretty reasonable answer for steel and concrete because we have decades of experience with it.
I’m not an expert in this space but this seems like an incredibly dangerous gamble to take for not much gain. Concrete and steel are reliable building materials that are mostly issues because of the energy cost to produce them. Fix the energy supply chain and they’re about as green as anything else.
This isn’t being pitched because it’s “better than steel and concrete” it’s being pitched as “green” and call me a cynic but if it was actually “better” than concrete and steel and safer than concrete and steel, they would outright say that. Arbitrarily being “more green” with no other information (and being based on a material that is supposed to combust but doesn’t), is a huge red flag.
NEVER live in one of these holy shit… There’s a damn good reason wooden skyscrapers aren’t a thing: FIRE.
They say in the article that this “mass timber” is considered “good enough” but personally I would not want to trust my life to that.
I live in a country where single family homes are built with wood. Everyone seems to trust their life to that. I don’t know why it would be different in an apartment.
Because these are literal sky scrapers. Fire on a wood structure is a recipe for catastrophic failure. A fire in a large structure could have similar effects to those large high rise condos that collapsed in Florida from poor maintenance.
This is very likely dangerous deregulation of the fire code to cut costs being “green washed” as a new thing that needs a hell of a lot more scrutiny. Building large structures with wood WAS a thing in the past, it was outlawed because it’s EXTREMELY dangerous when one of those structures ignites.
They’re only getting away with it because these are composite timbers which have been “tested” to be safer. I’m very skeptical that those tests are comprehensive, at least to the point where I would feel comfortable spending a significant portion of my life in one of these buildings.
i think you’re operating under 1) an extremely 1800s understanding of how fire-resistant a wood skyscraper would be and 2) a misguided understanding of where fire safety problems tend to come from in most contemporary buildings
wood is not uniquely flammable,[1] and the vast majority of the problem in a fire is not going to be with the actual wood itself (as is true of steel, concrete, etc.) but moreso with the fact that we make nearly everything that isn’t the building itself out of extremely combustible materials and we probably should not do that? as i recall that was the entire problem at Grenfell, where the cladding used was a flammable plastic that rendered any airgapping measures between flats useless and allowed the fire to spread uncontrollably. the fire at Grenfell also reportedly began from a refrigerator that was plastic-backed.
it can rather trivially be treated to be fire-resistant–and as the person you’re replying to notes has already been tested extensively and implemented in existing buildings to that end, and in multiple locales, just from a brief search on the subject ↩︎
https://www.youtube.com/watch?v=2qry7AmdIn8&t=328s
They tested it and mass timber columns are rated fire resistant for 3 hours.
Concrete is not entirely immune to fire either. [effects](https://www.edtengineers.com/blog-post/fire-effects-concrete], ratings Conditions and behavior are better known of course, given it’s prevalence and use.
In the example building covered by Vox, they built a concrete garage base and concrete cores that made it easier to be approved.
Either way, that’s what regulations are for. To ensure that the build is safe enough. There is no absolute safety.
We’re also living in an era where regulator bodies have been repeatedly weakened by large companies and interest groups.
Does that fire resistance hold up over a decade, two decades, a century, etc? Even if internationally regulatory bodies are 100% in good hands … there’s no way everybody is using the same blend of wood + fire retardant.
Also how realistic are the laboratory conditions? Do the same testing rules apply if an accelerate has been used to increase the burn rate?
What about the human impact? What’s the impact of inhaling smoke off of these? Environmental impact from the gasses inevitably produced?
How repairable is the timber structure in case of fire?
These questions have pretty reasonable answer for steel and concrete because we have decades of experience with it.
I’m not an expert in this space but this seems like an incredibly dangerous gamble to take for not much gain. Concrete and steel are reliable building materials that are mostly issues because of the energy cost to produce them. Fix the energy supply chain and they’re about as green as anything else.
This isn’t being pitched because it’s “better than steel and concrete” it’s being pitched as “green” and call me a cynic but if it was actually “better” than concrete and steel and safer than concrete and steel, they would outright say that. Arbitrarily being “more green” with no other information (and being based on a material that is supposed to combust but doesn’t), is a huge red flag.