During rehabilitation of residential buildings built in the first half of the
20th century, it is necessary to strengthen timber floors so they can
fulfill the requirements of strength and serviceability according to
contemporary regulations. Floors made of monolithic timber girders can be
most easily strengthened by forming a composite structure with a reinforced
concrete slab supported on a trapezoidal steel sheeting, with appropriate
connections between different materials. In the paper, the procedure of
calculation of nails used as shear connectors for composite action of timber
and concrete is presented. The procedure is based on equations given in
Eurocode 5, and besides that, a calculation applying FEM has been conducted,
and a comparison of results is presented.