This report presents the results of experimental tests performed on through-tenon joints used in double-layered and double-curved timber plate shells recently developed. Three tests were carried out to determine the semi-rigidity of these wood-wood connections in their three translational degrees-of-freedom. The objective of these tests is to obtain values of axial, shear and perpendicularto- grain compression stiffness of the connections used in large-scale assemblies tested, as well as their maximum capacity in all three directions.