The distortion behaviour of several wood-based floor structures with built-in heating systems was studied, both numerical simulations and full-scale tests of five different floor elements being performed. The floor elements were constructed industrially and were moved then to the testing laboratory, being exposed there to controlled floor heating and variations in climate. A threedimensional finite element model developed earlier for solid wood was further developed here for studying the global distortion behaviour of the floor elements with the aim to identifying and evaluating the various couplings in the thermal-hygro-mechanical problem that causes the distortions. The experimental and simulation results showed the distortions of the floor elements to be influenced by the shrinkage properties of the wood-based materials, the sawing patterns employed and the initial moisture conditions within the timber beams.