The paper presents the analysis of the influence of contact heat resistance inheat conductivity of layered unbound massive wood composite made of maple wood (Acer pseudoplatanus). A stationary experimental method was used, permitting continuous temperature setting independently of the test specimen. During the experiment, a significant humidity gradient occurred in the series of previously conditioned test specimens, which was exclusively the result of the Soret effect. Direct influence of the resulting humidity gradient on heat conductivity of layered composite was not analysed. The results of the analyses performed are presented and clarified. The hypothesis of a significant influence of contact heat resistance has been proven correct.