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

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51–60 of 83 posts

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

#51

I read this as "Mass Tinder" and it gave me an idea for a group dating app that helps organize strangers into meeting up as a group for "activities".

That's meetup.com

I think the gp had different „activities“ in mind.

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

#52
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.

> planted trees, which pull CO2 out of the air

When an old building is torn down and the wood is burnt all the CO2 goes back into the environment.

Unless we start burying old wood into sealed underground chambers (like depleted oil wells) all the CO2 stays around.

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

#53
post #8

Bigger question, how fire inspection ever cleared a wooden highrise?

Wooden houses catch fire relatively easily because they're made of many small pieces of wood. Larger, monolithic pieces of wood are considerably less flammable. (Imagine trying to start a campfire with a single log.)

This. If a log house or similar construction burns, the walls are often left standing afterwards. Solid logs are really slow burners.

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

#55
post #37

Earlier quoted context omitted.

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.

UBC's Brock Commons opened in 2017 and has 18 stories over 53m. And Mjøsa Tower was just finished (March 2019), also 18 stories but 85m. They all uses concrete though. Brock has concrete stairwell cores. Mjøsa apparently limited concrete to upper floor decks, for weighting (elevator shafts and stairwells are apparently CLT).

AIUI, concrete is there for fire code reasons. You want the stairwell to burn last to give everyone a chance to get out.

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

#58
post #12
post #8

Bigger question, how fire inspection ever cleared a wooden highrise?

This question comes up every single time anything related to wood construction is talked about. The keyword in mass timber is mass . It's quite hard to set a big mass of wood on fire. It burns slowly and relatively predictably -- meaning you have more time to evacuate. And because of its mass, an outer layer can char, burn out and leave the building standing. Also sprinklers.

The problem is the glue. When the glue melts (which it does at a much lower temperature than wood burns), the structural integrity is lost.

Firefighters do not enter new construction homes in the US because they often use these as floor joists. The time until failure has been greatly reduced compared to older homes. Things may have gotten better in the last few decades, but I'd like to see the data.

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

#59
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 is very susceptible to freezing water, and steel rusts. All building materials have flaws, this doesn't seem any less manageable than the flaws of the current most popular building supplies.

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

#60
post #37

Earlier quoted context omitted.

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.

UBC's Brock Commons opened in 2017 and has 18 stories over 53m. And Mjøsa Tower was just finished (March 2019), also 18 stories but 85m. They all uses concrete though. Brock has concrete stairwell cores. Mjøsa apparently limited concrete to upper floor decks, for weighting (elevator shafts and stairwells are apparently CLT).

The youtube video, and comment I was responding to talks about buildings made entirely out of wood, no glue, no insulation, no screws?, just wood.

With those sorts of constraints, you're going to be limited by how high you can build.

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