How to Heat a Radiant Floor

Lay out the copper tubing below the floor. The tubing should run between the floor supports, cross the support about 1 foot from the floor's end, and then run down the adjacent support in the opposite direction. The tubing will form a long S-shape once it is laid out on the floor.

Drill a hole just larger than the copper tubing in the supports at every place the tubing will cross the support and up close to the floor boards. The hole should be within 1/2 inch of the floor boards that sit on top of the supports. You can drill the hole from either side of the support, but it should be perpendicular to the support.

Feed the tubing through each of the holes in order and starting at one end.

Insert the tubing into the groove going down the center of the heat transfer plate then screw the plate to the center of the space between the floor supports. This keeps the copper tubing pressed up against floor board and helps dissipate heat evenly across the floor. Start this process at one end of the room and keep the tubing tight as you mount it to the floor.

Roll the insulation, with the paper side down, between the floor supports. This will prevent heat from radiating downward through the ceiling of the room below.

Connect the ends of the tubing to the heating unit. The precise method depends upon the specific heating unit and tubing you are using, but the best ones to use have a nut at the end of the tubing which screws onto the input and output of the heating unit. The unit heats water which is then pumped through the tubing under the floor. After the water releases all of its energy, it returns to the heating unit to be reused.