How to Heat a Floor Cheaply

Remove the existing floor surface. If it's a tile or hardwood floor, pry it up. If it's carpet, rip it up. Remove any bits of mortar, tack strips or nails in the subfloor. Sharp objects can damage the cable for the radiant heating system.

Wash the subfloor with a mild cleansing agent, and vacuum the subfloor.

Nail down any loose floorboards on the subfloor.

Draw the path of the heating cable onto the subfloor.

Attach cable strapping to the floor along the path of the cable with 3/8-inch serrated staples. Install the strapping every 2 1/2 feet.

Lay the cable onto the subfloor along the path you drew. Lock the cable into the strapping as you reach it.

Test the cable by connecting the leads from an ohmmeter to the cold lead conductors, which are the wires that lead from the heating cable. You should get a reading on the ohmmeter of between 10 and 250 ohms; if not, the cable may be damaged.

Prepare cement-based mortar, following the manufacturer's instructions.

Spread the mortar onto the subfloor, covering the cable, and allow it to set for the time specified on the packaging.

Add a second layer of mortar onto the subfloor, and allow it to set.

Install tile or hardwood for the new floor surface.

Hire an electrician to connect the heating cable to your thermostat and main electrical box. Most municipalities require that a certified professional complete this task due to the safety issues involved.