The rate of heat flow through a floor. Various resilient flooring materials have different characteristics which affect their conductance of heat flow to the top surface. With radiant heating methods (where instead of conventional radiators, pipes are laid into the subfloor of concrete, hot water or steam is passed through the pipes, and the room area is heated by warm temperatures rising through the floor and into the room), the thermal conductivity of floors does not present much of a problem (even with the thickest gauges of cork tile), but the resilient floor's resistance to indention may be lessened if the heating system delivers too high temperatures. With perimeter heating, where heat is supplied to a room through wall or ceiling pipe installations, wall and ceiling materials may be affected if the temperatures run too hot.