What is joinery, anyway?

What is joinery? Very simply - joinery is a term for working with wood by employing special joining techniques. When I worked as a carpenter, we joined pieces of wood together primarily through the use of nails. It is the unique qualities of wood that allow the use of nails. Just think about trying to nail two pieces of metal together or two pieces of stone. Both of these materials are too hard and/or too brittle to accept a nail. Many plastics will just crack, or if they don't crack, they will not hold the nail. There are similar issues for screws, which we also began to use more as carpenters early with the introduction of battery-powered drills and screw guns.

Though these are methods for joining pieces of wood, joinery generally refers to joining pieces of wood without the use of these metal fasteners. There are many types of traditional joints used in woodworking, but most rely on shaping two parts so that they interlock and have inherent resistance to movement. Of course, these joints (the best known being dovetails and mortise and tenons) must allow for assembly, so after they are slid together, they were traditionally either glued or pegged to prevent the reversal of the motion by which they were assembled. All of these joints were originally (and sometimes still) formed with hand tools. Again, it is the unique qualities of wood which allow these techniques. Wood is both soft enough to be worked readily with hand tools and at the same time hard enough that the joints formed are highly functional and durable.

There are now many power tools which can speed the work of the joiner, but the principles remain the same. Joints which stand the test of time must be tight fitting. If the joint allows for some movement, that movement will over time compress the fibers of the wood and loosen the joint. You have probably seen this in old chairs where parts that once fit snugly are now loose, compromising the integrity of the chair. Using high quality equipment can facilitate forming tight joints, which traditionally were formed by careful and time-consuming hand work.

Modern glues also ease this process and form bonds which are less susceptible to degradation over time. So joinery today has the potential to produce stronger and longer-lasting products than traditional pieces that were handed down for generations. One might ask why this is not the norm in our culture today, but that is a question for another time. But, if you would like your furniture and cabinetry to be useful for many years, then you might want to look for a joiner rather than driving to the nearest big box store.