This paper presents data of typical span lengths, used timber species and timber joist dimensions,and provides useful facts from different literature about timber floors in Slovenia. Additionally, an existing timber floor is checked according to the current building standards in the European Union, the Eurocodes. To prove the reasonability of preserving old timber floors, a possible addition of a concrete plate added on the top of the timber joists is studied. The analysis of maximum allowable imposed loads is carried out for different span lengths of the timber and the timber-concrete composite floor.