beveled lap joint

The pull lap joint represents a specialized longitudinal connection that constitutes an inverse variant of the oblique scarf joint. This joint utilizes the principle of form-fitting interlocking without additional wooden fasteners.
The pull lap joint belongs to the family of lap and butt joints. As an I-joint, it shows kinship with classical half lap joints and other longitudinal connections. In contrast to the stop-splayed scarf joint (oblique scarf), the oblique angle runs in the opposite direction.
Unlike the classical half lap joint, the laps do not run at right angles to the material but at oblique angles. The material at the end of the lap is thicker than at the beginning. The lap thus forms a scoop-like notch that engages with the corresponding scoop of the mating piece.
The pull lap joint enables improved resistance to tensile forces compared to the simple half lap joint through its special geometry. The scoop-like form prevents the connection from pulling apart under tensile loading. The connection functions without additional wooden fasteners such as wedges or dowels.
The connection requires precise craftsmanship as the oblique lap surfaces must fit exactly. Poor workmanship can create stress concentrations. The oblique cutting is more demanding craftwork than right-angled connections. The cross-sectional weakening is less than with simple half lap joints when correctly executed.
The pull lap joint provides good tensile strength in the longitudinal direction and offers improved stability against pulling apart. The scoop-like geometry enables partial force transmission even under tensile loading. The connection is stiffer than simple half lap joints but vulnerable to lateral forces.
The pull lap joint is traditionally used in sills in wall constructions, purlins in roof constructions, and wall plates. The connection finds application in ceiling joists and beams in floor and ceiling constructions. It is particularly suitable for longitudinal joints that must also resist tensile forces.
Manufacture follows traditional craftsmanship techniques with special consideration of the oblique cutting. First, the positions of the scoop-like notches are marked and the oblique angles precisely laid out. The notches are created using special sawing techniques for oblique cuts and then finished with chisels. The connection requires precise fitting work.
The connection can be executed at various oblique angles, with proportions adapted to timber thickness and forces to be transmitted.