Traditional timber joints behavior remains badly known. Recent studies have shown that some kind of carpentry joints can be considered as semi-rigid connections. Their rigidity (bending stiffness) in general sense plays an important role in computation of the global deformations and force distribution of timber roofing frames. Developments in computer-controlled manufacture of timber members enable a revival of traditional timber connections without steel fasteners. This study will focus on deformation, failure processes and bending stiffness of rafter-tie beam connection and modern tenon (dovetail) joint as secondary beam-main beam connection (both joints are made by CNC wood-working machine).