Wood will always strive for an equilibrium moisture level in relation to the air in the environment. Dinesen floors have been dried to 8-10%, and regardless of underfloor heating, they will contract in the winter, when the air humidity is low. With an interior air humidity between 40 and 45% RH, the wood will adapt to a moisture content of 8% wood humidity. If the air humidity drops to 30% RH, the wood will adapt to 6%, which means that it contracts. The underfloor heating does not in itself lead to larger contraction gaps. The higher the surface temperature, the larger the contraction gaps. You should expect the planks to contract by an average of approximately 1% in width, cf. Table 1.