Joining Timber

Joints are an important part of construction in almost any woodworking project, and the ability to make sound, well-fitting joints is the mark of a good craftsperson.

In joining, as in all woodworking, studying the grain direction and working with it are vital. Eventually it will become second nature to look at the grain in a piece of timber to see how best to work it. Also, you must always use sharp tools: blunt edges require greater pressure and this can cause fracture or splitting, even when working with the grain.

Get your teacher to cut two pieces of knot free, 12 mm thick pine, 100 mm x 15 mm, one with the grain going longways and the other across the width. Now, just using your hands, try to snap each in half and note the results.

Timber can be joined in two ways: first by purely gluing and joining the pieces until the glue dries (for example, a simple butt joint). For a strong joint this method relies on a large glue surface. The second method is to join the timber by mechanical means, which can be achieved by adding feathers, slip (loose) tongues , screws or nails (which can be hidden from sight later) or by using a joint that is designed to give its own mechanical advantage such as in a mortise and tenon joint - even this can be strengthened using dowel or wedges or biscuits. There are joints that are mechanically strong and are also used for aesthetic reasons like a dovetail joint.

Of course, all joints will use glue and may utilise one of the six methods above to further strengthen them. Therefore, when making something that requires timber to be joined there will generally be a selection of joints to choose from. A decision will have to be made as to how strong the joint needs to be and whether it needs to be reinforced further (i.e. with nails or screws etc.) in order to stand up to its designed use. With experience, this will be an easy decision, but initially a little research and your teacher's advice will be very helpful.

Types of timber joints

Timber joints are organised into the following three groups: Carcase joints, framing joints and widening joints.