Monday, March 2, 2015

Cross Laminated Timber - The European Answer to Housing

My latest article entitled Watch the Future of Robotic Affordable Modular Housing is about automated robotic steel modular residential structures and it led to an anonymous comment that made me stop and wonder if maybe I didn't give enough credit to what is happening in Europe.
I find this post totally disingenuous. On the one hand you dump on the people trying to change the modular industries image and on the other you show something that is unattainable in the US because of the prices we insist on paying for our housing. There are so few factories that build with steel in the US and none of them can do it for a price point that makes sense for residential construction.
The European system of cross laminated wood is much closer and much more attainable for US residential construction then welded stainless steel framing and I don't see you talking about or it making any inroads south of the Canadian border.
So while I found the video sort of interesting the question of why there is no one doing this in the US is not hard to fathom.
I have never tried to discredit any type of building method and I don't think Anonymous will find that I've ever tried to 'dump' on people trying to make changes in modular housing. 

What I don't do is talk much about are building systems that even though they are part of the larger systems built industry they aren't generally being used in modular construction. This blog is dedicated to modular residential housing after all.

So to make amends to Anonymous for apparently overlooking an entire construction method used by many other countries throughout the world I would like to explain what Cross Laminated Timber is and give you the nickle tour by video.

I went to the American Wood Council for their definition of CLT:
What is cross laminated timber?
 Cross Laminated Timber (CLT) is a flexible building system suitable for use in all assembly types (e.g., walls, floors and roofs).  Made from industrial dried lumber stacked together at right angles and glued over their entire surface, it is an exceptionally strong product that retains its static strength and shape, and allows the transfer of loads on all sides. Panels are prefabricated based on the project design and arrive at the job site with windows and doors pre-cut. Although size varies by manufacturer, they can be as large as 54.1 x 9.7 x 1.6 feet and include 3, 5, 7 or more layers.
 Common connections for CLT assemblies include wall-to-foundation, wall-to-wall (straight or junction), floor-to-floor, wall-to-floor, and wall-to-roof. Panels may be connected to each other with half-lapped, single or double splines made from engineered wood products, while metal brackets, hold-downs and plates are used to transfer forces. Mechanical fasteners may be dowel-type (e.g., nails, screws, glulam rivets, dowels, bolts) or bearing-type (e.g., split rings, shear plates).
Then I found a very helpful video that explains CLT:

Will CLT ever make headway into the modular housing industry?

Probably not anytime soon.

1 comment:

Anonymous said...

Although CLT's have some inherent advantages for structural and fire resistance they are really another form of panelized construction. If panels were able to speed modular construction many plants would have adopted them years ago. CLT's can and will play a role in heavy timber and multistory as an alternative to steel and concrete but I believe not so much in SFRs.

As far as robotic steel structures one has to only consider that these are being produced in the Far East and shipped competitively into the EU. It is not implausible that such could be built and shipped into the west coast or along the eastern seaboard as an alternative to "Blu Homes" or others using steel as their backbone.