5 ms·

The correct term is CLT (cross laminated timber). A big chunk of Katerra’s recent big financing is to pay for CLT factories. The cool thing about CLT is that i

The correct term is CLT (cross laminated timber). A big chunk of Katerra’s recent big financing is to pay for CLT factories. The cool thing about CLT is that it can be “printed” in arbitrary shapes and sizes in a factory setting and shipped to construction sites for rapid assembly. Structurally it can replace steel/concrete in a certain range of structures. The potential for automation and mass customization is absent from the article and the most exciting aspect of CLT. Factory prefabrication may also be a way to reduce construction costs and schedules in expensive areas like SF.

epistasis 7y ago
Im certainly no expert, but as far as terminology, mass timber seems to be a category that includes CLT as well as others: >Katerra's mass timber product line will include cross laminated timber (CLT) and glue-laminated timber (glulam) at both architectural and industrial appearance grades. https://www.katerra.com/en/what-we-do/products/mass-timber-products.html https://www.katerra.com/en/what-we-do/products/mass-timber-p... > Explore the supply chain for cross-laminated timber (CLT), nail-laminated timber, glulam beams and panels, mass plywood panels, dowel-laminated timber, and laminated veneer lumber; and the opportunities and obstacles for mass timber in global manufacturing and construction. https://www.masstimberconference.com/ https://www.masstimberconference.com/
- twelvechairs 7y ago
  Terms are used a little differently internationally. However with that said typically "mass timber" is the catch all for both engineered and non-engineered timber. CLT is the engineered product taking taking most of the limelight right now. It is only differentiated from glulam (glue laminated timber) by the layering. In CLT layers are perpendicular where glulam they are parallel. Glulam has been around a little longer and is more suited to posts and beams due to its linear nature where CLT is used for structural panels also. There are also plenty of other less glamorous engineered timber products that have had a major impact in construction including timber I beams and OSB (Oriented Strand Board) panels. If anyone is really interested in timber from forestry to bulding products I recommend looking at the Gifu Academy of Forest Science and Culture which is the only institution i know of that runs the gamut of forestry, environmental education, craft and furniture making, and wooden architecture
benj111 7y ago
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.
- masklinn 7y ago
  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 orientations; while for gluelam all layers have the same orientation so the end-result is closer in behaviour to regular sold timber.
  - benj111 7y ago
    Yes, I would guess constructions like this make use of both gluelam and CLT.
- jaggederest 7y ago
  https://www.youtube.com/watch?v=4j_UjIshzMc 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.
  - benj111 7y ago
    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.
    - masklinn 7y ago
      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).
shereadsthenews 7y ago
Mass timber technique goes beyond engineered wood. It can be simply piles of wood. I saw an architect’s own residence built entirely from sawn timber and pegs. It is also consider a mass timber structure. Engineered wood products may help span large distances and things like that but it seems like the category “mass timber” requires mainly the use of wood where previously one might have used another material, and the use of simply more wood instead of cavities. It is really the opposite of wood frame construction.
lucas_membrane 7y ago
Now in the US, building codes are allowing construction of buildings of 6 stories with only the first being concrete and iron, and the upper 5 wood frame with neither concrete nor iron structure, and such buildings are proliferating. Is this CLT a part of the rationale that such structures are acceptably durable?

epistasis 7y ago

Im certainly no expert, but as far as terminology, mass timber seems to be a category that includes CLT as well as others: >Katerra's mass timber product line will include cross laminated timber (CLT) and glue-laminated timber (glulam) at both architectural and industrial appearance grades. https://www.katerra.com/en/what-we-do/products/mass-timber-products.html https://www.katerra.com/en/what-we-do/products/mass-timber-p... > Explore the supply chain for cross-laminated timber (CLT), nail-laminated timber, glulam beams and panels, mass plywood panels, dowel-laminated timber, and laminated veneer lumber; and the opportunities and obstacles for mass timber in global manufacturing and construction. https://www.masstimberconference.com/ https://www.masstimberconference.com/

twelvechairs 7y ago
Terms are used a little differently internationally. However with that said typically "mass timber" is the catch all for both engineered and non-engineered timber. CLT is the engineered product taking taking most of the limelight right now. It is only differentiated from glulam (glue laminated timber) by the layering. In CLT layers are perpendicular where glulam they are parallel. Glulam has been around a little longer and is more suited to posts and beams due to its linear nature where CLT is used for structural panels also. There are also plenty of other less glamorous engineered timber products that have had a major impact in construction including timber I beams and OSB (Oriented Strand Board) panels. If anyone is really interested in timber from forestry to bulding products I recommend looking at the Gifu Academy of Forest Science and Culture which is the only institution i know of that runs the gamut of forestry, environmental education, craft and furniture making, and wooden architecture

benj111 7y ago

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.

masklinn 7y ago
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 orientations; while for gluelam all layers have the same orientation so the end-result is closer in behaviour to regular sold timber.
- benj111 7y ago
  Yes, I would guess constructions like this make use of both gluelam and CLT.
jaggederest 7y ago
https://www.youtube.com/watch?v=4j_UjIshzMc 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.
- benj111 7y ago
  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.
  - masklinn 7y ago
    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).

shereadsthenews 7y ago

Mass timber technique goes beyond engineered wood. It can be simply piles of wood. I saw an architect’s own residence built entirely from sawn timber and pegs. It is also consider a mass timber structure. Engineered wood products may help span large distances and things like that but it seems like the category “mass timber” requires mainly the use of wood where previously one might have used another material, and the use of simply more wood instead of cavities. It is really the opposite of wood frame construction.

lucas_membrane 7y ago

Now in the US, building codes are allowing construction of buildings of 6 stories with only the first being concrete and iron, and the upper 5 wood frame with neither concrete nor iron structure, and such buildings are proliferating. Is this CLT a part of the rationale that such structures are acceptably durable?