Lap joints combine the interlocking characteristics of rabbets and dadoes in a number of different configurations to join two boards face to face. Lap joints are a better alternative to butt joints for frame construction, because laps offer much more gluing area and the pieces actually interlock mechanically. Usually, the thickness of both parts of a lap joint are equal, and the pieces fit together so that both faces of each joint part line up with one another. In order to do this, the overlapping dadoes or rabbet tongues are as large as the mating piece is wide.
LAP JOINTS are, In essence, extra-wide rabbet and dado joints. They’re used primarily in furnituremaking and frame-making, where the extra gluing surface in the sturdy interlocking joints greatly Increases the strength of any project
Three of the more common lap joint types are the corner half lap, “T” half lap and cross lap. Corner half laps consist of two wide rabbets cut across the faces of two workpieces at the ends. The cheek portion of each rabbet matches the width of the opposite workpiece. “T” half laps fasten the end of one board with a wide rabbet to the midsection of another board that’s fitted with a matching dado. Cross laps are half-lap joints where both members are dadoed and the joint is not at the end of either part. All three types are made by cutting a wide dado into each joint member—either on the face or edge—then interlocking the dadoes.
FRAMES. Picture frames, frame-and-panel frames or any time you’re joining work-pieces on the flat and you want the faces to be flush is a good time to use lap joints.
How To Make A Half-Lap Joint
Learn how to make a super-strong half-lap joint, just one of the nine essential joints you should consider for your project. WOOD magazine’s Craig Ruegsegger shows you not only how to make the joint, but why this joint might be the best choice for your project.
How to Make Half-Lap Joints on a Table Saw | Tricks of the Trade
Half-lap joints are quick to make and not only add strength but can be used to visually improve a design. Once you get the saw set up, it’s quick work to make one or one hundred.
A Woodworking Joint That Every Beginner Should Know
Leah demonstrates how to make a lap joint with two pieces of wood, using very few tools.