Abstract: Cogging piece (1) for use when notching log constructional elements (2) to other log constructional elements (2) or to corresponding separate log constructional elements (9). The cogging piece is adapted to be attached to both ends of each log constructional element (2) and to the end of each end constructional element (9) that is adapted to face a cogged joint. The cogging piece (1) is provided with lateral (4at, 4bt, 7at, 7bt) and axial (5at, 5bt, 6at, 6bt) inclined surfaces that are adapted to rest against corresponding axial and lateral surfaces respectively of cogging pieces attached to below and/or above intersecting log constructional elements and end constructional elements. Thus an increasing vertical force on a wall leads to an increased axial contraction of the cogged joints in the same wall.

Abstract: Cogging piece (1) for use when notching log constructional elements (2) to other log constructional elements (2) or to corresponding separate log constructional elements (9). The cogging piece is adapted to be attached to both ends of each log constructional element (2) and to the end of each end constructional element (9) that is adapted to face a cogged joint. The cogging piece (1) is provided with lateral (4at, 4bt, Tat, 7bt) and axial (5at, 5bt, 6at, 6bt) inclined surfaces that are adapted to rest against corresponding axial and lateral surfaces respectively of cogging pieces attached to below and/or above intersecting log constructional elements and end constructional elements. Thus an increasing vertical force on a wall leads to an increased axial contraction of the cogged joints in the same wall.

Abstract: Constructional element intended for cogged joining having side walls of a single wooden or wood-like element; preferably both side walls are made of solid wood. Each element is preferably furnished with longitudinal grooves on its inside, curved across its longitudinal axis and on its inner side coated with a layer of plastic material, preferably thermoplastic material, which may also partially or completely surround ribs that hold the curved side walls in a stable position. The invention also concerns a method for the manufacture of the constructional element as well as a method for the manufacture of structural elements that constitute complete side walls of such a constructional element.