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I do wonder what fresh new health conditions we will learn are caused by that "engineered" fire-resistant wood in a couple of decades. I'm also not fond of "en

I do wonder what fresh new health conditions we will learn are caused by that "engineered" fire-resistant wood in a couple of decades. I'm also not fond of "engineered" as a form of sanitising what is really happening: the wood is either sprayed with or treated with some sort of fire-retardant that will remain on the wood for its usable lifespan. Unlike other terrible things that we use in constructions but then cover up, the wood is also more likely to be left exposed in the interior of the building as a stylistic choice.

jaclaz 3y ago
Yes, it is very possible that "engineered" fire-resistant wood (and all the added chemicals that come into play with that) could be toxic, one way or the other, we are already using in construction lots of "engineered" (composite) wood, and I am personally not much convinced that even that is really-really "safe". As a reference, for formaldehyde emissions: https://en.wikipedia.org/wiki/Formaldehyde https://en.wikipedia.org/wiki/Formaldehyde https://en.wikipedia.org/wiki/Formaldehyde#Safety https://en.wikipedia.org/wiki/Formaldehyde#Safety it took decades to categorize them as toxic/carcinogen and then put limitations in Laws and building codes.
Mistletoe 3y ago
I don’t think it gets its fire resistance by things sprayed on. https://www.greenspec.co.uk/building-design/crosslam-timber-fire-resistance-and-rating/ https://www.greenspec.co.uk/building-design/crosslam-timber-...
alkonaut 3y ago
CLT burns, like glulam, but it just burns very slowly. Importantly it also retains it's strength for a long time while burning. So basically: you have combustible buildings but you have buildings you can get out of while they are burning. I have not heard about use of fire retardants on CLT/Glulam even in highrise construction, but I do know that many wood highrises "cheat" and use steel beams where it makes sense. Is this really exotic enough to even warrant discussion? What is it that makes it stand out? There are of course large developments with wooden houses (rows and rows of thousands of apartments/townhouses) that are only slightly lower at 2-3 floors, but that have existed since the 40's and 50's. Is it that it's within a city rather than more suburban? Or that it's 4-5 floors? Or that it's mixed residential/commercial?
IIAOPSW 3y ago
What exactly is euphemistic or sanitizing about saying out right that a chemical engineer engineered some chemicals for a generally desirable purpose.
- TaylorAlexander 3y ago
  I guess a more specific term would be “composite”.
fodkodrasz 3y ago
I'm considering to build a house with light-frame monocoque technology, which is unfamiliar/unpopular and somewhat new here in Hungary. My fears are also along these lines, I wonder if the glues used in the KVH "engineered timber" beams, or in the OSB boards would have health impacts. Not to mention the insecticides, the fungicides, flame retardants. Also there is little to no experience in long-term maintenance costs of these building technologies in Eastern Europe (only with more traditional log-house wood building methods), I'd be happy if I could get any info on it from people with experience on this (maybe from the Nordic region, or the USA probably). Oh the technology is basically: - wood frame from engineered timber, - OSB for lateral structural integrity (both inside and outside), - semi-permeable humidity closing layer - rock wool insulation - few centimetres of dense EPS foam on the inner side, over the OSB (this is where the wiring/plumbing is done in, traces cut with heat-knife), - and wood or drywall finishing on the inside - outer finishing can be wood or anything used for traditional buildings As per current building code automated continuous ventilation needs to be added with heat exchangers, which I think alleviates some of the VOC (formaldehyde) problem. (sorry for the possibly bad translation, I don't know the proper industrial lingo) This technology promises 20-30% cost savings from traditional brick based technology used extensively here, better net area (less lost on wall thickness for same level of heat insulation). On the other hand its longevity has no well-known track record here, so insurance costs may be higher, etc...
jrowen 3y ago
I'm really confused by the "sanitising" comment - I understand "engineered" to refer to the whole manufacturing process, the fact that it resembles and functions similarly to "raw" solid wood but has been broken down and rebuilt with different properties (of which fire-resistance is just one). What would be a better name? Is "pressure-treated" sanitized because it doesn't really convey what chemicals are involved? I'm having a hard time envisioning how the general name for this class of products would be expected to better reflect the potential presence of fire-retardant chemicals.
jillesvangurp 3y ago
Fire resistance with CLT is not provided by chemicals. When it burns, the wood chars on the outside which then insulates the rest of the wood. So, it takes quite some time for this to escalate to the point where the structural integrity is compromised. And it takes quite a bit of heat to keep it burning to begin with. Basically, eventually it would fail if you don't extinguish the fire. But this takes quite some time. CLT is basically rated for how long that takes. As for toxicity, CLT is basically laminated wood with modest amounts of glue (compared to other laminated woods that people use in their homes without much issues). Mostly the glue stays on the inside where the layers are. And of course the glues used have all sorts of desirable properties with respect to not being toxic, bad for the environment, etc.

jaclaz 3y ago

Yes, it is very possible that "engineered" fire-resistant wood (and all the added chemicals that come into play with that) could be toxic, one way or the other, we are already using in construction lots of "engineered" (composite) wood, and I am personally not much convinced that even that is really-really "safe". As a reference, for formaldehyde emissions: https://en.wikipedia.org/wiki/Formaldehyde https://en.wikipedia.org/wiki/Formaldehyde https://en.wikipedia.org/wiki/Formaldehyde#Safety https://en.wikipedia.org/wiki/Formaldehyde#Safety it took decades to categorize them as toxic/carcinogen and then put limitations in Laws and building codes.

Mistletoe 3y ago

I don’t think it gets its fire resistance by things sprayed on. https://www.greenspec.co.uk/building-design/crosslam-timber-fire-resistance-and-rating/ https://www.greenspec.co.uk/building-design/crosslam-timber-...

alkonaut 3y ago

CLT burns, like glulam, but it just burns very slowly. Importantly it also retains it's strength for a long time while burning. So basically: you have combustible buildings but you have buildings you can get out of while they are burning. I have not heard about use of fire retardants on CLT/Glulam even in highrise construction, but I do know that many wood highrises "cheat" and use steel beams where it makes sense. Is this really exotic enough to even warrant discussion? What is it that makes it stand out? There are of course large developments with wooden houses (rows and rows of thousands of apartments/townhouses) that are only slightly lower at 2-3 floors, but that have existed since the 40's and 50's. Is it that it's within a city rather than more suburban? Or that it's 4-5 floors? Or that it's mixed residential/commercial?

IIAOPSW 3y ago

What exactly is euphemistic or sanitizing about saying out right that a chemical engineer engineered some chemicals for a generally desirable purpose.

TaylorAlexander 3y ago
I guess a more specific term would be “composite”.

fodkodrasz 3y ago

I'm considering to build a house with light-frame monocoque technology, which is unfamiliar/unpopular and somewhat new here in Hungary. My fears are also along these lines, I wonder if the glues used in the KVH "engineered timber" beams, or in the OSB boards would have health impacts. Not to mention the insecticides, the fungicides, flame retardants. Also there is little to no experience in long-term maintenance costs of these building technologies in Eastern Europe (only with more traditional log-house wood building methods), I'd be happy if I could get any info on it from people with experience on this (maybe from the Nordic region, or the USA probably). Oh the technology is basically: - wood frame from engineered timber, - OSB for lateral structural integrity (both inside and outside), - semi-permeable humidity closing layer - rock wool insulation - few centimetres of dense EPS foam on the inner side, over the OSB (this is where the wiring/plumbing is done in, traces cut with heat-knife), - and wood or drywall finishing on the inside - outer finishing can be wood or anything used for traditional buildings As per current building code automated continuous ventilation needs to be added with heat exchangers, which I think alleviates some of the VOC (formaldehyde) problem. (sorry for the possibly bad translation, I don't know the proper industrial lingo) This technology promises 20-30% cost savings from traditional brick based technology used extensively here, better net area (less lost on wall thickness for same level of heat insulation). On the other hand its longevity has no well-known track record here, so insurance costs may be higher, etc...

jrowen 3y ago

I'm really confused by the "sanitising" comment - I understand "engineered" to refer to the whole manufacturing process, the fact that it resembles and functions similarly to "raw" solid wood but has been broken down and rebuilt with different properties (of which fire-resistance is just one). What would be a better name? Is "pressure-treated" sanitized because it doesn't really convey what chemicals are involved? I'm having a hard time envisioning how the general name for this class of products would be expected to better reflect the potential presence of fire-retardant chemicals.

jillesvangurp 3y ago

Fire resistance with CLT is not provided by chemicals. When it burns, the wood chars on the outside which then insulates the rest of the wood. So, it takes quite some time for this to escalate to the point where the structural integrity is compromised. And it takes quite a bit of heat to keep it burning to begin with. Basically, eventually it would fail if you don't extinguish the fire. But this takes quite some time. CLT is basically rated for how long that takes. As for toxicity, CLT is basically laminated wood with modest amounts of glue (compared to other laminated woods that people use in their homes without much issues). Mostly the glue stays on the inside where the layers are. And of course the glues used have all sorts of desirable properties with respect to not being toxic, bad for the environment, etc.