Due to the increased strength and deformation properties of waterproof construction plywood in comparison with wood, it is advisable to design load-bearing beam elements consisting only of plywood. High technical and economic indicators distinguish such structures. In addition, plywood beams can be easily made in a collapsible version if their elements are manufactured on numerically controlled machines. The methods and results of experimental studies of a new type of collapsible beams developed entirely from plywood sheets without adhesive joints are considered. Experimental structures are beams 1.5 m long. The load was applied in the form of two concentrated forces in thirds of the span with the beams hinged to the supports. Experimental studies have confirmed a sufficient degree of strength and rigidity of the proposed design solutions. It is shown that the design methodology for plywood beams made on tenon ties should be based on the theoretical provisions for calculating composite wooden elements. The experiments carried out confirmed the correctness of this approach. In the engineering calculations of the proposed type of structures, it is recommended to determine the geometric characteristics of the design cross sections in the form of the moment of resistance and the moment of inertia, taking into account the compliance of wall connections with chords using the coefficients kw and ks.