Adding heat to a tile installation is getting easier and easier. Yet, there are still some issues these well-known heat systems have not solved. The main issue is “heatsink.” Heatsinks have been used in computers to lower the temperature of a CPU by using a medium or material to draw the heat away. In a typical tile installation, the concrete slab or the wood substrate draws heat energy away from the tile. The thermostat is fighting heatsink by increasing energy to heat the tile to the desired temperature. Some savvy installers and homeowners recognize the issue and use products such as Cerazorb or cork underlayment. These are good options, but are costly and require additional time to install. One company has ingeniously added a layer of material beneath the membrane to insulate heatsink. Unfortunately, the insulation properties are too low to make a big difference. An effective solution was yet to be determined until now.

My name is Cory Rundle. I have been in the tile industry for 25 years, including sales and installation. I have developed an insulated tile backerboard that is pre-grooved for electric resistance heat cable. I call it HeatBoard. The core is made of Polyiso, which has the highest insulation value per cubic inch of any known building material used today. Fiberglass facers are added to the core for strength and has properties to allow modified thinset to cure properly. This board has a Robinson floor test rating of “light commercial traffic.” The dimensions of the board are .47-inch-thick by 30- x 36-inch manageable panels. HeatBoard can be installed directly to a concrete slab or approved wood substrate. The patent is still pending on HeatBoard.

In early 2016, I was searching wedi’s website for information on Wedi Board. I noticed wedi was using a 2-inch-thick EPS foam board with grooves for flexible pipe using hydronics to heat tile. I wondered if that would work with electric heat. I researched the effects of heat cable on different types of foam core boards. After three years of testing, I developed a heated floor product that does not require self-level or heavy screed and heats tile up to 4.5 times faster. I began testing HeatBoard in the field in 2017 and started selling HeatBoard at a local tile store in 2018. The feedback was very encouraging. Contractors love HeatBoard because they do not have to screed a smooth layer of mortar. Most contractors also know the headaches that self-leveling compounds can cause.

I once had a bathroom tile job that was on the upper floor of an old house. I did not have the perimeter sealed well enough, so the self-level leaked down through the door casing of the lower dining room. The self-level continued to the basement floor. Replacing and repairing the old door casing and hardwood floors of that job left a sour taste in my mouth for decades about self-level. The contractors that use HeatBoard are excited and have regained confidence in installing heated floors. Homeowners are impressed with how efficient the system is. They can heat their tile floor at a fraction of the cost of their past installations. I have a mock-up installation of HeatBoard that has been running non-stop for four years. For the month of August last year, my energy cost was $2.36. For the month of March this year, my cost was $4.13.

Last Christmas, I installed 300 square feet of HeatBoard in an enclosed sunroom. This was not in a conditioned space so the homeowner needed to use this system as supplement heat for the room. She had existing wall unit electric heaters that were loud, smelly and expensive to run. I installed the HeatBoard with a modified thinset mortar, Ardex X77, leaving a gap between the boards for expansion and additional space for the heat cable. I ran the cable into the grooves in the desired heat areas. I chiseled a 3- x 3-inch pocket between two heat cables for the sensor wires and ran the lead cable up the wall for the thermostat. HeatBoard cuts with a utility knife and is easy to notch or chisel additional grooves as needed. The HeatBoard panels lay flush and offer a smooth surface to install tile. Using the flat edge of my trowel, I skimcoated thinset over the cables and installed tile.

The homeowner sent pictures of herself enjoying the warm, quiet space. She is so grateful she did not have to use those loud, smelly wall units any longer. And the dogs love it, too.

HeatBoard may be purchased at your local tile store, from your tile installer or directly from