Abstract: A floor heating system includes a flooring substrate having a heating or cooling element in heat transfer relationship therewith. A heat spreader is in heat transfer relationship with the flooring substrate. The heat spreader includes a layer of flexible graphite material. A floor covering overlies the layer of flexible graphite material. Temperature variations across an exposed surface of the floor covering are reduced by the presence of the flexible graphite heat spreader, thus providing an improved and more uniform heating to the floor and to the room with which the floor is associated.