Wood Joints: notes

Why joints matter

A joint joins two pieces of wood. A good joint is strong, neat and suited to the load it carries. Glue, screws or pegs are used with it.

Common joints

• Butt joint: two flat ends meet. It is the simplest and weakest, and needs nails, screws or dowels.
• Halving joint: half the thickness is cut from each piece so the surfaces finish level. Used in frames.
• Housing joint: a slot (the housing) cut across a board takes the end of another board. It is common for shelves.
• Mortise and tenon: the tenon is the projecting tongue; the mortise is the slot it fits. It is the strongest frame joint, used for doors and table frames.
• Haunched tenon: a small extra step stops the tenon twisting and fills the groove at the top of a door frame.
• Dovetail joint: fan shaped pins and tails lock tightly and resist being pulled apart. Used in drawers.
• Dowel joint: round wooden pegs fit into matching holes. They are used for edges and frames.
• Mitre joint: two pieces cut at 45 degrees make a right angle corner, as in picture frames. The end grain is hidden.
• Tongue and groove: boards interlock along their edges, as in floorboards and panelling.
• Rebate joint: an L shaped step cut along an edge, used where a back panel or glass fits.

Choosing

Pick the joint by the strength needed, the look wanted and the tools at hand.