Cogged Lap Joint Plans

cogged lap joint plans

The cogged lap joint is a stronger variant of the half lap joint. On a regular half lap joint, half of the beam is removed, unlike this joint where most of the beam remains intact. It’s used often in Japanese temple construction to secure purlins onto rafters. The additional shoulders also add strength against racking and twisting compared to the half lap version.

For instructions on making the joint, you can see my Joinery Class Episode 2 below: