From log cabins to cross-laminated timber
I was born in a log cabin. I guess that makes me a “man of the people” alongside Abraham Lincoln and many others that preceded me. Or maybe I’m only guessing about the log cabin part, and likely exaggerating. I was actually born in Johanna’s Maternity Home, which was a refuge for farmers’ wives that were a long way from a hospital.
Johanna was a local midwife without family, and she had a few spare bedrooms. And her home may well have been logs — underneath the wood siding. Its squat stance and small windows hint at that. After a few days there, I was moved back to the farm into a building that I know was made of logs, although it, too, was covered in siding.
In some ways, my own experience of wood buildings follows the history of that in Canada, especially that of the Prairies. The homesteaders, who were in my case my grandparents, built with what they had and they had more trees than money. At first, the domiciles were usually of logs and were intended to be temporary. They were often then converted to “homes” by applying wood siding to the outside and plaster to the inside. That was my first experience.
As prosperity allowed, a second home was built of stud-wall sticks. These were often two storied on a fairly small footprint, which helped with keeping the house warm in the winter. Again, and later, if prosperity allowed, a “ranch” style house was built alongside and this time with indoor amenities. And now the new homes are almost indistinguishable for largish suburban ones.
Building with wood has gone from logs to cut lumber in various configurations and approaches. And now what appears to be adding a major alternative is building with panels. Not just small panels, but the whole sidewall of a building in one go. Compared to building with logs, which is very much (usually) an artisanal operation, building with studs and joists is an industrialized approach. If we take that further and assemble the sticks into larger components in a factory, the industrialization of building with wood has made a large step forward.
There seems to be basically two approaches to this. One is to build large panels that have basically a stud-wall logic and many constituent materials. The other is to build what most closely resembles plywood, but in this case, the plies are actually pretty thick: dressed two-inch material. They are edge glued (sometimes) and face glued, with alternating layers oriented at 90 degrees.
Once this panel, usually up to 10 feet by 40 feet, is assembled, it can be CNC squared and milled with openings and wire management cavities and other special considerations. It will be trucked to a site and crane lifted into place, where it can be readily fastened together with special hardware. Larger panel sizes are also available in some places.
This parallels, with a 60-year time lag, what occurred with furniture. At one time, woodworkers started with the tree. Then they used cut lumber. And now, most of what is built uses one type of pre-made panel or another. This has allowed for the genuine industrialization of woodworking, with the skill being represented in the equipment and design, rather than in the hands of the worker.
For wood buildings, in the future, the factory may be where most production occurs, with the advantages of more reliable and better weather, greater accuracy and quality control and less need for high and specialized skill. It also allows for much quicker construction. The output is dimensionally stable and structurally sound. It can be used not only for walls but also for floors, ceilings and roofs. The wood can be left exposed for the interiors and, depending on the treatment, on the exteriors as well.
Other benefits are improved safety, reduced labour costs, and ease of modification: the changes are made on the computer and the equipment does the rest. There are some significant sustainability benefits here too.
There are some very interesting buildings being built with cross-laminated timber. Of course, building codes need to be adjusted and that will be a challenge. But some brave architects are taking this on, with surprising and exciting results.
I find this all very interesting. It seems to be still early days and I’d be very happy to hear from anyone that is active in this area: firstname.lastname@example.org.
Paul Epp is professor at OCAD University and chair of its Industrial Design Department.