How to install TempZone Flex over Cork Underlayment

Hello, I'm Scott from WarmlyYours, and today we're going to be installing electric radiant heat on a concrete slab. Here you can see some of the tools that we'll be using. Our process begins with placing cork over the concrete slab using thinset. We will roll it out onto the floor and then cover those rolls with thinset and tile. Now that we've got the cork laid out, it's time to install the first piece. I've taken out our layout and marked the location of each piece, as I will need to pull this back to apply thinset. Using a 1/8 inch V-notch trowel, we will spread the thinset, set the cork into it, and then lift it to check for good coverage. If the coverage is satisfactory, we will put it back down and use a roller to finish that area.

When you receive your order, you'll find several important items inside the box. Among them is your installation plan and the installation manual, both of which will be in a plastic bag. The rolls will also be included in the box, along with the circuit check devices necessary for installation, thermostats, and any other controls you may have ordered. It is crucial to check the contents of the box against your packing list and ensure that they match the items listed in your installation plan.

I have located the plan for this room and started by measuring each direction to confirm that the room's dimensions match those in the drawing. Once verified, I transpose the areas indicated on the drawing onto the cork flooring. As soon as you take the rolls out of the box, it is essential to test each roll with an ohmmeter to ensure it is in good working condition. This step is crucial, as replacing a damaged roll can be quite costly. To test, connect the red probe from your ohmmeter to the red wire and the black probe to the black wire, checking that the resistance matches within 15% of the ohm value indicated on the UL label.

According to our plan, we will be doing a 14-foot 6-inch run of this heating roll. I've marked the starting point on the floor, and we will roll it out, ensuring we have the correct length before making our first cut and turn. The measurements provided in the plan, such as 14 feet, 12 feet, and 11 feet, represent the actual footage of the green mesh. For this installation, we have prepared a panel measuring 14 feet 6 inches. I will make a mark at this point and use scissors to cut the mesh, being careful never to cut the wire. Once I reach the end of the loop, I will carefully separate the loop from the mesh, ensuring that the scissors do not damage the wire.

Next, we will prepare for the next panel, which requires a length of seven feet three inches as indicated in our plan. After marking the run, we will make the necessary cut and turn. Some plans may include a number inside a circle, indicating that a specific amount of green mesh must be removed from the product, allowing us to freeform with the heating cable. This technique is essential for navigating around obstacles like posts or doorways. After making the cut, we will freeform the wire area as indicated on the plan.

To secure the freeform wire, we recommend using a glue gun. Apply glue to the cork floor, press the wire into the glue, and cover it with cold water. For added protection, you can use excess mesh to cover the wire, securing it with glue or staples, but never staple the wire itself. Once the heating rolls are down, we need to route the cold lead back to the thermostat. The blue wire is the heating wire, while the black wire serves as the cold lead, which does not heat up beyond this point.

After routing the cold lead along the room's perimeter and into the conduit up to the thermostat, we will attach our circuit check device to the wires. The circuit check will have red, green, and black terminals. Connect the red wire from the heating system to the red terminal, the black wire to the black terminal, and the braided ground to the green terminal. Before applying thinset over the rolls, it's crucial to install the thermostat sensor if your system uses one. Again, we will use an ohmmeter to ensure the sensor is functioning correctly, setting it to the 20K range to get the proper operating range.

Once we have tested the sensor and confirmed it is in good condition, we will place it into the mesh between two wires. It is important that the sensor wire does not run over a heating wire but instead goes through an open loop at least six inches into the mesh. After placing the rolls on the floor, we will conduct a second ohm test to ensure everything is still functioning properly. This test is just as important as the first, as we want to avoid covering a damaged roll with thinset.

Now that we have all the rolls down, we will demonstrate a one-step installation. This method is faster and may be suitable for experienced tilers, but for beginners, we recommend a two-step process to ensure uniformity in tile height and avoid high or low spots. Using a 3/8 inch notch trowel, we will apply thinset over the heating cable, taking care not to damage it. After installing the safety circuit checks, we will ensure the cable is facing downward as we apply the thinset.

Once we have placed the first tile, we will check for good adhesion before moving on to the second tile. It is crucial to clear any thinset that may rise between the tiles, as this can lead to issues later. Using a toothbrush to clean out the grout joints while the thinset is still wet is a good practice. This concludes the one-step installation process. For a two-step installation, we will wait for the skim coat to dry before proceeding with the tile installation, which is the recommended method for beginners or those facing larger projects.

With the skim coat applied over the heating rolls, we can now install our tile using a 3/8 inch notch trowel to apply thinset. After the tile is installed, it is vital to ensure that thinset does not remain in the grout lines. Cleaning the grout lines while the thinset is still wet is essential, as using a blade later can damage the heating wires beneath the tile.