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As Mass Timber Takes Off, How Green Is This New Building Material?

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Re: As Mass Timber Takes Off, How Green Is This New Building Material?

#31

Post by WalterBright »

proee wrote: post #24

Termites are going to love this ;-) Even with termite treated lumber, they will still need annual inspections to look for damage. If they do find out the structure is laden with termites, it would most likely require a complete evacuation of the building and "tenting" to gas them out - which might be tricky if it's in an urban area. Also, any undetected leaks in the structure could cause slow rotting of the wood.

Concrete rots away if it is not protected properly from water. It soaks up water, the rebar rusts, expands, and splits the concrete.

Re: As Mass Timber Takes Off, How Green Is This New Building Material?

#32

Post by perfunctory »

rjf72 wrote: post #16

Would this not be just another form of kicking the can? In particular once these buildings are demolished and replaced with new ones, I don't imagine that the old wood would (or even could) be reused. Instead it'd be sent to a landfill and decay at which point its stored carbon would be released. In favor of this regardless. Wood is so much more pleasant on the eyes, and creating an incentive for huge sustainable for…

> Instead it'd be sent to a landfill and decay at which point its stored carbon would be released.

Even then it's still carbon neutral. Or am I missing something?

Or, since carbon is gonna be released anyway, we could burn it and make some energy as a bonus.

Re: As Mass Timber Takes Off, How Green Is This New Building Material?

#33

Post by [deleted] »

ilaksh wrote: post #25

I will just say the obvious thing. I thought we were supposed to be planting more trees. Doesn't cutting more of them down go in the opposite direction? I like the idea of engineered wood for construction. I am just suspicious that a lot of this hype is coming from the logging industry and the CO2 stuff is just a marketing coup.

[deleted]

Re: As Mass Timber Takes Off, How Green Is This New Building Material?

#34

Post by WalterBright »

ilaksh wrote: post #25

I will just say the obvious thing. I thought we were supposed to be planting more trees. Doesn't cutting more of them down go in the opposite direction? I like the idea of engineered wood for construction. I am just suspicious that a lot of this hype is coming from the logging industry and the CO2 stuff is just a marketing coup.

There's a great deal of land that could be covered with planted trees, which pull CO2 out of the air. When they are mature, then they can be used as building material, and a new tree planted.

Re: As Mass Timber Takes Off, How Green Is This New Building Material?

#35

Post by willyt »

barrkel wrote: post #20
benj111 wrote: post #7

Earlier quoted context omitted.

Centuries? Reinforced concrete is 150 years old, steel frame construction a little less so.

Sure, but we have concrete buildings still standing from Roman times - most famously, the Pantheon. I grew up in a cottage a couple of hundred years old, with thick walls built from stone and mortar. It's not unusual to live in a house that's over a century old in Europe. I've also lived in a wooden house - more of a three room + toilet chalet, really. Biggest irritations were all the noises from thermal expansion in…

Roman concrete doesn’t have the same chemistry as modern concrete.

Re: As Mass Timber Takes Off, How Green Is This New Building Material?

#36

Post by myspy »

Funny that this topic is coming up, we're currently in the execution of building a house made of this material. We did choose the CLT because of the spruce interior look. But not all walls are like that. Most part will be covered by clay plaster. This should also help with soundproofing.

As for the glue. We asked the producer and they use a glue which has no negative side effect when finished hardening but is not that nice to breath while being in production.

Apparently there are no better glues. Another option would be to use only wood, but this is not CLT, it has another name, but the same result. The difference is that the interior has to be covered by something because the wall looks rough. And it costs a little more.

Termites are no problem in Europe and leaking water is a problem in every type of house, but it won't go undetected for long.

As we live in areas with houses made of wood around 300 to 500 years ago and those houses still standing and being ok, I plan our home to be here for the same amount of time :)

Re: As Mass Timber Takes Off, How Green Is This New Building Material?

#37

Post by benj111 »

jaggederest wrote: post #21
benj111 wrote: post #6

Earlier quoted context omitted.

Came here to say this, I've heard it called 'glue lam' also. Who the hell thought up the mass timber name though?! That just says to me a solid (mass) of unengineered wood.

https://www.youtube.com/watch?v=4j_UjIshzMc That's literally what it is. You can do it in all sorts of interesting different ways, but the idea is, where with other techniques you'd use e.g. insulation, gypsum wallboard, oriented strand board sheathing or plywood, instead you just... put more wood on it.

There's no mention that this doesn't contain insulation etc, and does explicitly mention that glue is used.

I'm not sure you could use that building technique for anything over a few stories.

Re: As Mass Timber Takes Off, How Green Is This New Building Material?

#38

Post by benj111 »

masklinn wrote: post #15
benj111 wrote: post #6

Earlier quoted context omitted.

Came here to say this, I've heard it called 'glue lam' also. Who the hell thought up the mass timber name though?! That just says to me a solid (mass) of unengineered wood.

I guess they mean the main structural mass is timber-based? It's really odd terminology but might simply crop up from details of the field's lingo which makes no sense to outsider. Apparently CLT and gluelam are different methods of engineering wood: in CLT the boards are laminated in cross-frames (so one layer is laid north-south and the next is east-west) to improve structural resistance across non-longitudinal ori…

Yes, I would guess constructions like this make use of both gluelam and CLT.

Re: As Mass Timber Takes Off, How Green Is This New Building Material?

#39

Post by willyt »

Once you have more than about 150mm (6”) of insulation a typical building will be losing more energy through air leakage than through conduction. CLT in particular is excellent for airtightness because it is pretty airtight in of itself and it comes in big accurately machined panels which minimises the number of joints that need to be sealed up.

Re: As Mass Timber Takes Off, How Green Is This New Building Material?

#40

Post by jabl »

willyt wrote: post #35
barrkel wrote: post #20

Earlier quoted context omitted.

Sure, but we have concrete buildings still standing from Roman times - most famously, the Pantheon. I grew up in a cottage a couple of hundred years old, with thick walls built from stone and mortar. It's not unusual to live in a house that's over a century old in Europe. I've also lived in a wooden house - more of a three room + toilet chalet, really. Biggest irritations were all the noises from thermal expansion in…

Roman concrete doesn’t have the same chemistry as modern concrete.

And, Roman concrete doesn't have steel rebar which rusts and cracks the concrete.
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