Tricks of the Trade: Electric Radiant Heating for Tile Floors

Hello and thank you for joining our webinar today entitled "Tricks of the Trade: Electric Radiant Heating for Floors," mainly tile floors, as it says right there. I'm Scott from WarmlyYours, and I'm Greg. We're excited to share some tricks we've learned from our customers in the field to help you with your floor installations. If you have any questions, please feel free to type them into the white spot in the middle on the left side of your screen. We encourage you to ask anything at any time. We also have many questions submitted ahead of time, and we'll be discussing what's coming up for next month, so if you're interested, you can send us your questions when you receive the link to sign up for next month's webinar. Your questions help us provide the information you're looking for to assist you in your everyday life.

So, Greg, tell us about WarmlyYours and why people should choose us. Sure! We've been in the floor heating industry since 1999 and have expanded into various areas related to cable heating specifically. We were the first in the industry to provide an online tool for project planning and overnight plans. If you submit us a floor plan, we’ll get you back a design by the next business day, which can be very handy. Additionally, we offer 24/7 tech support. Scott and others from our office take a cell phone home, and calls are routed directly to them, ensuring you receive direct support from WarmlyYours, not from another vendor. We can help you with any questions you have during your installation process, and we’ll provide our contact information at the end of the presentation.

Now, let's talk about electric floor heating for tile, which is the focus of our discussion today. Greg, can you explain the different iterations of TempZone? The two products displayed on the screen include the green mesh, which holds the wire spacing in place. This is a stock product available in various sizes. If you send us a plan, we can customize how it's cut and laid out in the room. This gives you the speed and flexibility of a stock product combined with a custom layout. The product below, the cable, can be used in a couple of ways. Traditionally, the cable is installed by placing fixing strips on each side of the room and stringing the cable back and forth. This method is still widely used, and I encountered someone on a job site this morning who preferred it. They appreciated the control it provided over cable placement.

Another increasingly popular method involves using uncoupling membranes designed to receive the cable. Instead of fixing strips, you push the cable into the uncoupling membrane, allowing for faster installation and the added benefit of protecting the floor. We’ll discuss membranes further in this presentation. We received a question from Pablo regarding the voltages and frequencies available for these products. The options are 240 and 120 volts, and frequency is not an issue since the thermostat adjusts to any frequency. In North America, the frequency is uniform. Additionally, custom mats are available in 208 volts, so if that’s what you have in your location, we can accommodate that.

You can use the 240 mats with 208 volts, but they will only output 86% of their rating, which is still sufficient for nearly every application to warm the floor. Now, let’s discuss how to measure properly for a quote. If you're preparing to install heating in a basement, what information do customers need to provide to ensure we can create an accurate plan? Measuring for flooring differs slightly from measuring for floor heating. Generally, when measuring for flooring, you take the overall dimensions to figure out the square footage, possibly adding a little overage. This process is relatively straightforward unless the area has an unusual shape.

However, measuring for floor heating is more akin to measuring for cabinets. We need to know the locations of all fixtures, vanities, vents, posts, and anything touching the floor to design around them. This upfront effort will pay dividends on installation day. In the plan displayed, we highlighted in red some elements that people often forget to include. Each red rectangle represents air vents, while the boxes represent posts that support the floor above. Each of these red spots reduces the available square footage for heating. If you measure accurately but then reduce the available space, you risk having too much mat or cable. Remember, we never heat under permanent fixtures, so always field verify your dimensions after receiving your plan.

When creating your drawing, don’t forget to include vents and permanent fixtures. It's always better to err on the side of caution and have a little too little than too much. Now, let’s take a look at this installation plan. This layout is for one of the TempZone flex rolls, specifically a 43-foot long roll. It serves as a map for installation, showing exactly where the heat will be. With any floor heating product, you can expect heat to radiate approximately an inch and a half away from the mat, but not further. The green areas on this drawing indicate where the mat is located. The triangle with two lines indicates the beginning of the mat, while the square marks the end.

It's crucial to inform us of the thermostat's location, as it will influence our design. For instance, if the thermostat is in the lower right corner of this drawing, the cable may not be long enough to reach it. The cold lead, which does not heat, is only 15 feet long. If the thermostat is positioned elsewhere, we can adjust the drawing accordingly. You don’t need to know the thermostat’s location to provide a quote, as long as the room area remains consistent. If the area changes dramatically, the price may vary. Once the order is placed, we can quickly turn around a new drawing based on the updated thermostat location, often within the same day.

If you have questions about the drawings within the plan, feel free to call us. We can clarify any details, although that topic is for a different webinar. I want to draw your attention to the lower part of the installation plan, where the electrical specifications are listed. Here, you’ll find the wattage, amperage, and breaker size required for the product. This information is essential for your electrician to ensure proper installation.

Now, let’s discuss these unusual devices that might resemble something from a sci-fi movie. These are simple tools designed to ensure your installation is functioning correctly and to prevent problems during the process. The circuit check verifies continuity, ensuring a complete circuit throughout the cable. You’ll use this once you’re ready to install. The other device is a digital ohm meter, which is essential for testing the product. When you receive your floor heating package, the first step is to perform an ohm test. We’ll include instructions in the packaging, and our 24/7 tech support is available to guide you through the process step by step.

It's crucial to test the product immediately upon delivery and again after laying it down. You want to ensure the product is in good condition before installation. The worst-case scenario is installing a damaged product without knowing its condition. The digital ohm meter is a valuable tool, and it’s now very affordable, typically costing around $15. Every job should include this testing to confirm you’re installing a quality product. After testing, you can proceed with your cuts and turns, then test again before covering the cable with the floor covering. Finally, document the results in the installation manual for your records.

Another good practice with the circuit check is to leave it on after completing the job but before the electrician installs the thermostat. This way, if other tradespeople are working in the area, they’ll be alerted if they accidentally damage a wire. Let’s move on to the next tip, provided by Mike at MK Design Build, regarding setting the foundation. Floor preparation is essential, whether you’re installing floor heating or not. For most flooring types, starting with a level surface is crucial. If there are any cracks in the foundation, they should be repaired before proceeding.

When preparing the surface, follow the manufacturer’s instructions regarding mixing and whether a primer is necessary. Each product may have different requirements, but the process is generally straightforward. Ensure that you block any areas where self-leveling material could drain, as it has a slurry-like consistency and will flow to create an even surface. Additionally, check for holes in the floor, as unsealed holes can lead to pooling in a basement. During a remodel, inspect the floor and remove any nails or debris to prevent them from being pulled up with the self-leveling compound.

This picture illustrates a properly leveled surface, which is essential for a successful installation. Remember to level the floor first, then install the cables, and finally pour the self-leveling compound over everything. We’ve spoken to installers who have worked in older homes where floors may sag over time, creating uneven surfaces. In such cases, the center may be significantly deeper than the edges, which can affect heating performance.

Now, let’s discuss applying thinset with electric floor heating. The process is similar to that of self-leveling. Each thinset has specific mixing ratios, so it’s crucial to follow those instructions. Applying thinset isn’t dramatically different from standard tiling. You can either screed a small area, pressing the thinset into the mat, or apply a skin coat over the entire area, allowing it to set before tiling. The mesh holds the cable in place, ensuring the correct distance apart. If the wires are too far apart, they won’t feel warm, while if they’re too close, they risk overheating.

Dande Electric recommends using modified thinset for this application, which we agree with. However, if you’re using Perdesso, the uncoupling membrane, check the manual for the appropriate thinset type based on your subfloor. Generally, modified thinset should be used below the tile and for back buttering. Avoid using pre-mixed thinset; instead, mix it on-site for optimal results.

When it comes to curing, you should not turn on the electric floor heat until the thinset has fully cured, as indicated on the bag. Premature heating can alter the thinset’s molecular structure, compromising its bond.

Let’s talk about sensors. Some companies suggest multiple sensors or installing conduit for easy replacement, which can be excessive. Our sensor failure rate is extremely low, below 1 in 10,000. Installing a second sensor is inexpensive, typically under $10, but only one sensor should be attached to avoid confusion for the thermostat. Instead of running conduit, simply add a separate sensor.

You don’t need to place the second sensor in the middle of the floor; it can be positioned along the edge, about six to eight inches in. Some installers weave the sensor through the mesh to hold it in place during installation.

Now, let’s discuss uncoupling membranes, specifically the blue Perdesso membrane. Uncoupling is a method used to allow movement without transferring stress to the tile. This technique has been utilized for centuries in European churches, where floors remain in excellent condition due to the uncoupling layer.

Perdesso was designed to simplify the installation of uncoupling membranes by incorporating channels for thinset, allowing for easy cable placement. Many installers prefer this method for its advantages, including vapor management. However, not every floor requires a membrane. For small spaces with minimal deflection, such as those with two layers of plywood, a membrane may not be necessary.

The size of the tile also plays a role; very small tiles may not work well with uncoupling membranes. In such cases, it’s better to use cable with fixing strips or custom mats. For concrete floors, our synthetic core, Cerazorb, provides excellent insulation and crack suppression, outperforming uncoupling membranes.

Perdesso is ideal for many applications, especially in master baths with complex layouts. It can also eliminate the need for a second layer of plywood in some cases. Always refer to the installation manual for guidance.

Now, let’s discuss grout flow. Although we’re not grouting here, a grout float can save time and simplify the installation process. Using a float allows you to push the cable into place without using your hands, which can be cumbersome. Ensure the float is resilient enough to push the cable down without damaging it.

When replacing tiles with electric floor heat underneath, it’s essential to avoid transferring shock to surrounding tiles. Start by removing the grout around the damaged tile to prevent breaking adjacent tiles. Carefully clean out the thinset to the thickness of the tile, avoiding any deeper cuts that could damage the heating cable.

We received a couple of questions that we’ll address at the end of the presentation, but first, let’s discuss using a thermal camera to locate heating cables. This tool can help you identify where the cables are before breaking up the tile. By marking the cable’s location, you can avoid damaging it during the removal process.

After using the thermal camera, attach the circuit check to the cold leads before chiseling. If you accidentally hit the wrong spot, the alarm will alert you to the issue.

Now, let’s move on to managing cold lead paths. The cold lead connects the heating wire to the thermostat and should be embedded in thinset or self-leveling compound. Ensure that the end cap, heating wire, and factory splice are properly buried, while the cold lead can remain above.

When routing cold leads, it’s important to avoid crossing them with heated wires. Keep the cold lead as short as possible, and consider using construction adhesive instead of nails to secure it. If the cold lead runs along the wall, inform the trim installers to nail straight to avoid hitting the cable.

Now, let’s address some questions submitted ahead of time. Maria asked if installation differs under stone composite flooring, such as Gemcore. The answer is yes. Luxury vinyl tile encompasses a wide range of products, and each may have specific requirements for radiant heat. For example, Gemcore recommends a half-inch separation between the cable and their flooring.

We always strive to provide the best recommendations based on the exact product being used. As products are tested and proven in the field, their requirements may become more lenient. It’s essential to follow the manufacturer’s installation instructions to maintain warranty coverage.

Jack asked how many coats of thinset are typically needed. The answer varies based on your installation method and experience level. You can either screed a small area or apply a skim coat over the entire area. Using self-leveling compound is highly recommended for small tiles to ensure a flat surface.

Dipty inquired about the maximum tile thickness for effective heating. Ideally, the distance from the heating cable to the top of the tile should be about one to one and a half inches. The closer the cable is to the surface, the better the heating performance.

In summary, when heating a shower or bench, ensure the cable is placed as close to the surface as possible. The same thinset that holds the tile should also secure the heating element. If using a pre-made shower pan, avoid placing the cable underneath it, as the heat will not transfer effectively.

We encourage you to join our next webinar, titled "Floor Heating Cable Installation: Uncoupling Membranes vs. Fixing Strips," scheduled for Thursday, July 12th, at 1:00 PM Central Time.

Greg, could you tell us about the monthly promotion? We’re currently offering free ground shipping. Feel free to reach out for a quote; we recommend providing floor plans for a more accurate estimate.

We value your feedback, and much of this webinar was based on your questions. Please let us know what topics you’d like us to cover in future webinars. You’ll receive an email shortly after this session, and we encourage you to share your thoughts and suggestions.

If you have any installation questions or issues, remember that we’re available 24/7 at 800-875-5285. You can also email us at info@warmlyyours.com or reach out to our owner, Julia Billen, at jbillan@warmlyyours.com.

Thank you for joining us today, and we hope you found this information helpful. Until next time, stay warm and be radiant!