What Are Wood Joints?

Various types of wood joints are used for trim.

A wood joint is the intersection where two pieces of wood are joined together. Moldings such as window and door casing, baseboards, crown molding and cabinets all have wood joints.

Types

The most common type of wood joints are butt, miter, dado, tongue and groove, and dovetail. The butt and miter joints are cut without jigs or special blades and used extensively in construction. The dado, dovetail, and tongue and groove joints require additional setup.

Function

Butt and miter joints are used for door and window casing and other applications when there is little pressure on the joint. The dado is often used for fixed shelves in cabinets and bookcases because the shelf fits in a tight groove which supports a lot of weight. Dovetail joints are very strong and are commonly found in drawers of high quality cabinets. The tongue and groove joint is used where blind nailing or additional support is needed between the framing members.

Considerations

Butts and miters can be cut on a miter saw whereas a dado, dovetail, and tongue and groove joint usually are made in a shop environment due to the additional tools, setup, and stability that is required.

Strengthening Wood Joints

Glue wood joints together. Wood joints that are not glued may loosen up after a period of time. Adding pocket screws, biscuits and other fasteners greatly strengthens the joint.

Tools

A biscuit joiner and pocket screw jig are the most common tools used for wood joints. The biscuit joiner is used mostly for an alignment tool, but does add some strength. The pocket screw jig is found in just about every professional woodworking shop because of its functionality and time saving uses.

References

• Woodworking Terms and Joints
• Woodworking Joinery

Resources

• Pocket Screw Jig