Abstract: A mounting plate for securing the heating pipe of a radiant heat system to the subfloor. The plate is a flat sheet with a groove in the upper surface and a plurality of legs underneath. The plate is composed of a rigid and highly heat-conductive material, preferably aluminum and aluminum alloys. The legs form large air gaps which can be left empty or filled with insulation to raise the efficiency of the system. The groove runs from one edge of the plate to another. The bottom of the groove is preferably semicircular, with a diameter the same as the outside diameter of the pipe so that heat transfer is maximized. The pipe is retained in the groove by a ridge running the length of the groove or by forming the groove in an omega shape so that the pipe must be snapped into the groove.