Duralay Heatflow for CarpetDuralay Heatflow underlays, all have lower tog ratings, which allow the warmth generated by underfloor heating to pass quickly into the room. They conduct more heat than other underlays, making them the ideal choice for installations with underfloor heating, bringing greater heating efficiency and the potential of reducing heating bills. Interfloors unique manufacturing techniques allow the production of underlays with higher thermal conductivity and