I use the term “traditional” timber framing to describe the system of joining timbers to each other without benefit of metal or mechanical fasteners. Typically, posts, girders, rafters, king and queen pins, etc., are connected to each other by the use of time-tested joinery such as mortise and tenon joints, scarf jointing, dovetails, rabbetting, etc. A good example of traditional timber framing is seen in Figure 2.17, in the next chapter.
In most cases, one or more people will lay out the various sides, gable ends, and “bents” (internal wall framing or other internal structural assemblies) on the ground. Time and care are taken to join the various heavy timbers by one of the many clever and intricate joints that have evolved over the centuries. Sometimes, particularly with owner-builders, a completed section will be raised with the help
of friends, so that there is room on the site (or foundation slab) to build the next component. Alternatively — and this is more common with experienced timber frame builders — the entire barn or house frame may be erected in a single day Professionals often manufacture all of the components in a shop environment, making sure that the pieces fit together properly, and then reassemble the frame on site.
Although traditional timber frames are sometimes used with natural infill alternatives, they are more commonly built to support pre-made insulated panels on the exterior, with wooden siding installed later. The fine joints are in evidence on the internal skeleton of heavy timbers, a beautiful and impressive effect. Spacing of vertical members is more critical when applying manufactured stress skin panels than it is when a natural infilling is used between posts. See Appendix C and the Bibliography for resources about stress skin panels, and structural insulated panels.
Done professionally, traditional timber framing can be quite expensive because of the labor and materials cost, but good timber framers are worth every cent they get in terms of quality. Owner-builders can do the work, too, but developing and using the required skills will add very much more time to the project. I am an experienced owner-builder, but I would certainly take a two-week course at one of the building schools before embarking on a traditional timberframing project.
Timber Framing for the Rest of Us
Strong, functional, and attractive timber-framed buildings are made by farmers, carpenters, and owner-builders throughout the world, and only a small proportion of these projects involve traditional timber framing. Most of these rural buildings — even houses, when heavy timbers are used — involve the use of truss plates, joist hangers, pole-barn nails, log cabin spikes, gravity, screws, bolts and ingenuity. These builders learn from their neighbors, family, local builders, and sometimes just by asking advice at the local sawmill or lumberyard. It’s sort of like the way beavers and other building species learn their trade.
But sometimes it’s hard to find someone to help on the project, so here we are. Now we need to talk about some basic structural principles.
