In addition to their basic function playwood boards can be used also as a heat insulator . We studied the effect of moisture, density and coating system on the rate of heating, on the thermal diffusivity and on the thermal conductivity. Playwood boards were constructed from three layers of spruce wood with total thickness of 26 mm. Variability of the examined parameters was very large therefore we were not able to confirm the statistical differences. In average the playwood board without coating had slightly better thermal insulation than boards whit melamine coating. With higher density thermal conductivity slightly increases by Boards with melamine coating exhibited somewhat dependency from density and moisture content.