Kehlbalken

Kehlbalken (German for “throat beam”) is a structural timber element commonly used in traditional roof construction and half‑timber framing. The beam spans horizontally between the lower ends of two inclined rafters, tying them together and preventing outward thrust that would otherwise spread the roof structure. By counteracting the horizontal component of the rafters’ forces, the Kehlbalken enhances stability and allows larger roof spans without excessive wall thrust.

Historically, Kehlbalken appeared in medieval timber‑framed buildings throughout Central Europe, especially in Germany, Austria and Switzerland. Early examples were hand‑hewn oak or pine, often reinforced with iron straps. In later periods, sawn timber and engineered wood products such as glulam or LVL replaced solid logs, improving dimensional accuracy and load capacity. The beam may be plain, or it can be incorporated into a decorative framework where it also serves as a visual base for the roof’s interior.

From an engineering perspective, the Kehlbalken functions as a tie beam, bearing primarily tension while also supporting a portion of the roof’s dead load. Design codes require the beam to resist the calculated tensile forces with an appropriate safety factor, taking into account wood grade, moisture content and connection details. Connections are typically realized with mortise‑and‑tenon joints, metal plates or bolts, ensuring adequate shear transfer between the beam and the rafters.

Modern applications of Kehlbalken include restoration projects, where historic construction techniques are replicated, and new timber‑frame houses that adopt traditional aesthetics while benefiting from contemporary materials and analysis methods.