# Cross Laminated Timber FYI



## mtlogcabin (Aug 18, 2011)

http://dailyinterlake.com/news/local_montana/article_96df8742-c937-11e0-933c-001cc4c002e0.html

Something new going up in the state. Maybe it will catch on

http://www.storaenso.com/products/wood-products/products/clt-cross-laminated-timber/Pages/cross-laminated-timber-clt.aspx


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## mark handler (Aug 18, 2011)

From woodworks.org

http://www.woodworks.org/files/PDF/Presentations/SE-Nov-2010/Mohammad.pdf


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## DRP (Aug 18, 2011)

Interesting, I wonder what the stress is like through moisture cycling using cross laminated boards?


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## Paul Sweet (Aug 19, 2011)

I don't think electricians will like it very much.


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## mark handler (Aug 19, 2011)

We all have been using cross laminated sheathing for years, Its called plywood.

With exterior glue it is semistable in moist conditions

They are now making it into framing Timbers.


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## DRP (Aug 19, 2011)

Do you think a veneer develops the same shearing forces along the glueline when moisture conditions change in a cross grain lamination compared to a board?


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## KZQuixote (Aug 19, 2011)

DRP said:
			
		

> Do you think a veneer develops the same shearing forces along the glueline when moisture conditions change in a cross grain lamination compared to a board?


Yep!

Additionally, boards are NOT what they used to be. I won't even use plywood anymore, made that decision twenty years ago. I'll take the uniformity of OSB over a delaminated plywood deck any day.

The best OSB is Weyerhaeuser Edge Gold. Leaves GP and LP all swollen and pouting every time.

Bill


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## mark handler (Aug 20, 2011)

Cross-laminating layers of wood veneer improves the structural properties of wood by distributing the along-the-grain strength of wood in both directions, and this means that CLT panels can be used to form complete floors, walls and roofs.

While CLT is a timber product, it should not be thought of as a timber frame product - it is a timber panel product that actually has similar characteristics to that of a pre-cast concrete panel.


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## DRP (Aug 20, 2011)

Understood, I can't answer my question either.  I see from your link the concerns are shared. Neat concept but I'll wait to see how it performs.

KZ, osb is also cross grain laminated, follow your logic, those same shearing stresses would then be present in the flake... I'm skeptical. (I switched too at about the same time and for the same reasons, I attributed it to QC)


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## DRP (Sep 4, 2011)

If I attached that right this is a scan of a page in "Design of Wood Structures", Breyer. This is not exactly the scenario but shows the concern I have. The text cautions about moisture change between assembly and service. The equilibrium moisture content in most of Europe will be higher than what I would expect in MT and the species will be different so it would be good to hear how this performs over a few seasons.

View attachment 476


View attachment 476


/monthly_2011_09/crossgrain.jpg.9c3f85c8c27919753b39a1d98dd4b32a.jpg


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## brudgers (Sep 5, 2011)

There is a good article in the latest issue of construction specifier. I expect that cross laminated timber has some potential for commercial construction because of the low embodied energy.


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## Pcinspector1 (Sep 6, 2011)

From Mark Handlers first post:

The information from Woodworks.org pdf there is a Question: What about electrical wiring?

Is there an answer in the pdf? Did I miss it?

pc1


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## brudgers (Sep 6, 2011)

Pcinspector1 said:
			
		

> From Mark Handlers first post:  The information from Woodworks.org pdf there is a Question: What about electrical wiring?  Is there an answer in the pdf? Did I miss it?  pc1


  As with most prefabricated elements, facilitation for wiring would normally be designed into the product.


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## mark handler (Sep 6, 2011)

Pcinspector1 said:
			
		

> From Mark Handlers first post:  What about electrical wiring?


Just like any Structural Insulated Panels (SIPs) most are installed in prefabricated channels,


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