Because heat flows evenly in all directions until it encounters a layer of thermal resistance, installing a layer of Econoboard Insulation Boards beneath the Underfloor Heating to act as a thermal resistance layer and prevent downward heat loss is highly recommended. Stopping this downward heat loss reduces the time it takes for the Underfloor Heating to heat up and can improve its efficiency by up to 50%. However, if this is not taken into account during the height construction, the heating will still work, but it will be less efficient and take longer to warm up.