Ultimate Guide to Radiant Floor Heating Installation

Heated floors are a great alternative to more traditional forms of heating. It is a cleaner, more effective solution that is fairly easy to install. This article includes everything you may want to know about heated flooring and radiant floor heating installation.

How Does Radiant Heat Flooring Work?

Radiant floor heating is a form of heating that uses thermal radiation. The heat that is generated from these systems radiates upwards, first warming the floors before continuing up and penetrating adjacent objects. Thermal energy in the air, produced by the radiant energy, is transferred through electromagnetic waves. 

These waves, while unobstructed, have potential energy. Once they encounter an obstacle, that energy is converted into heat and transferred to the other object. These obstacles can be floors, walls, furniture, or even people and pets. This process makes rooms feel warmer at lower temperatures and increases the temperature in the rooms much faster than traditional heating systems. 

Types of Radiant Floor Heating

There are two primary types of radiant floor heating systems: electric and hydronic radiant heating. They each have their advantages and disadvantages. Both systems can work for new construction and remodeling, though there are many other factors to consider when installing radiant floor heating.You also should consider factors such as the size of your home or space, your local climate, and, most importantly, your budget.

Electric Radiant Heating

Electric floor heating systems are becoming more popular with homeowners looking for more warmth than their traditional systems provide. Unlike forced air heating systems that circulate air to distribute the heat and also cause dust, germs, and allergens to spread throughout the room, electric radiant heating uses electromagnetic waves and doesn’t circulate air. You can install electric radiant floor heat systems under various types of flooring, including concrete tile, laminate, wood, and more. These systems are easy to install and are an excellent option for remodeling projects because they do not require plumbing or pumps and don’t create significant height differences in flooring. They also don’t require any bulky equipment, making them an “invisible” heating system.

Hydronic Radiant Heating

The second option is hydronic radiant heating, which still uses electromagnetic waves to produce heat. The difference is in how the heat gets produced. As the name implies, a hydronic system uses water to produce the heat. The water is pumped through a series of pipes under the floor and transmitted as heat into the room. 

Some people consider hydronic systems more energy efficient since they use water to create heat. This water is heated in a boiler before being pumped to the final location. Hydronic systems also have some disadvantages to consider, especially when it comes to remodeling spaces: 

1. These systems are expensive to install and require both licensed plumbers and electricians.
2. These systems are not ideal for remodeling jobs because they require more floor space to include the boiler, pumps, and network connections for the plumbing.

However, if you are performing a new construction rather than remodeling, hydronic systems are worth considering.

Best Places to Install Electric Heated Flooring

You can install electric radiant floor heat throughout your entire home. Some of the best places for heated floors include:

Bathrooms

Bathrooms are among the most common places people consider installing heated flooring systems. Nobody likes to step on cold floors as they step out of the shower, especially in winter; radiant heating will ensure you remain comfortable every season.

Bedrooms

You can’t expect to get a good night’s sleep if you’re shivering under your blankets. Space heaters may provide relief, but they also pose many risks, including a potential for fire and burns. Radiant heating eliminates these risks, creating a safe, warm, and comfortable environment for a restful night’s sleep. 

Kitchen

Kitchens are another popular place for heated flooring. Much like bathrooms, cold kitchen tiles can be incredibly uncomfortable and make focusing on cooking difficult, even with the stove or oven on. 

Underfloor heating will not warm up the tiles and the room, keeping them at the perfect temperature. These systems also don’t circulate dust and germs like a traditional heating system, creating safer, cleaner heat. 

Basements

Most homeowners use their basements for either storage or as a hang-out space for friends and family. The problem is that basements are cold. Installing heated floors will provide much-needed warmth to keep everyone comfortable without any cold spots. 

Home Offices

Just like you need a comfortable environment to sleep in, you need a comfortable environment to work in to be productive. Heated floors will provide silent, consistent heating so you are comfortable doing your work without needing space heaters or blankets.

Materials for Radiant Floor Heating Installation

Before you begin your electric heated floor installation, ensure you are prepared with all the necessary materials. These materials include:

• The heating system you are installing. This includes the mats, membranes, and cables required. 
• A floor-leveling compound or thinset to ensure a smooth, level surface for installation.
• Insulation to provide better heat loss resistance. Depending on your product, you can use Warmup Ultralight Insulation Boards or Insulated Underlayment. 
• A compatible thermostat that will allow you to control the system.
• Systems like DCM-PRO also require a Perimeter Strip and Waterproofing Kit. 
• A digital multimeter will test the resistance of the heater and floor sensor.
• Electrical tape for securing the floor sensor. 
• UL/cUL certified electrical housings, back boxes, and junction boxes to meet National electrical code requirements and ensure your heating system functions safely and effectively.
• UL/cUL certified electrical conduit to house the power leads.
• Your choice of flooring, ensuring it is compatible with your heating system.
• A utility knife for cutting membrane.

How to Install Electric Radiant Floor Heating 

When installing a heated floor system, it is important to take your time and work with a professional as needed. Installing your system correctly is vital to its function and safety. 

Here is a brief look at how to install radiant heat flooring. However, please refer to the specific product manual for more detailed and product-specific instructions.

1. Have a Professional do the Electrical

Start with getting the electrical connections in place before installing electric radiant floor heating. Electric radiant heat systems must be connected to the electrical system using a UL/cUL certified Ground Fault Circuit Interrupter (“GFCI”). If you don’t use a GFCI-integrated thermostat, ensure the branch circuit supplying your heaters is GFCI-protected. Use a dedicated GFCI-protected circuit to supply each heat zone, if possible. These connections are crucial to the system’s function and should only be done by a qualified electrician, according to the National Electrical Code and all relevant local Codes.

2. Prepare Your Space

Once you have the electrical, you are ready to prepare your floors for installing your radiant heating system. This means removing the existing flooring, including any glue, leaving a clean subfloor. You want the subfloor to be dry, smooth, and dust-free.

If necessary, apply a leveling compound and allow it to cure completely to ensure you have level flooring. You can also prime your subfloor as needed, using the appropriate solution. 

3. Install Insulation

To increase the effectiveness and efficiency of your floor heating system, you want to install insulation according to their instructions. What you use depends on your heating product. Warmup Ultralight Insulation Boards, for example, are applied using a flexible cement-based adhesive to clean and level subfloors.

4. Apply Perimeter Strips if Necessary

Perimeter strips allow for differential movement between the finished floor level and walls. These strips are installed along the perimeter of the space, ensuring the adhesive touches the wall and floor.

5. Test the Heating System

Before beginning the electric floor heating installation, you must test your heating element. Use your multimeter to measure the resistance of the heating element between the core wires and compare that number to the number on the UL tag. While some variance is acceptable, it shouldn’t be more than 15% more or less. 

Then, you want to measure the continuity between the core and ground wire. That should be ready for “O/L” or “Infinity.”

If the system fails either test, do not install the system and, instead, contact the manufacturer.

6. Lay the Mat or Membrane Material

The next step in electric radiant floor heating installation is laying the membrane that holds the cables. Apply a layer of thinset and stick the membrane to it, putting pressure to eliminate any air pockets. Continue this process until the entire space is covered in the membrane, using a utility knife to make any necessary cuts. 

To protect the membrane during installation, cover it with walking boards.

7. Plan the Layout of Your Cables

A plan of how you will lay the cables is critical. You will keep a copy on a control card to avoid potential damage to the system during cutting or drilling.

8. Lay Your Cable

Finally, you can start laying your heating cable. Start by placing the cold tail on the floor and cutting a section in the membrane for the manufactured joint to ensure it sits at the same height, and secure it using electrical tape. Begin laying the cable, pressing it between the membrane pegs, and following the system-approved layout.

Review your progress at the midpoint and ensure you are installing the cable correctly. Once you reach the end of the cable, you will do the same thing you did with the manufactured joint but do not tape over it.

8a. Waterproof the System

If you are installing the system in a wet area like a bathroom, you need to waterproof everything. To do this, apply your leveling compound and then the waterproofing material, like Warmup Waterproof Tape, smoothing it with a trowel to eliminate any air bubbles. Use care to ensure that you don’t damage the cable. 

9. Install Your Flooring

Now that the cable is installed, you can apply a thinset layer to help set everything in place, allowing it to cure before moving on the floor installation.

Only use approved flooring materials with your chosen system, installing it as instructed by the floor manufacturer. 

7 Tips for Effective Radiant floor Heating Installation

1. Make Sure You Calculate the Install Area Correctly

Before you even purchase your heating system, you need to know how much you need for radiant floor heating installation. To get this number, you want to determine the total square footage of the space you are measuring. Once you have that, you want to subtract any unheated spaces; this includes any furniture or other permanent fixtures. Multiply that number by 90%, and round the result of that calculation to the nearest cable size, as cables cannot be cut.

For example, say you have a bathroom that is 7′ by 12′, equalling 84 sq ft. of space. You also have 10 sq ft of vanity space, a 9 sq ft shower, and 3 sq ft toilet–added together, which is 22 sq ft of unheated space. Subtracted from the total square footage, you are left with 62 sq ft. Multiplied by 90%, you get 55.8 sq ft. For Warmup, the next closest cable size would be 66.3 ft. 

2. Choose the Right Insulation

While not required, underfloor insulation is highly recommended to improve heating times and decrease heat loss. Adding insulation can also help with noise reduction and waterproofing. 

There are many different types of underfloor insulation, including:

• Fiberglass: Fiberglass is a popular option made from glass fibers or sand that is effective and affordable. It will not perform as well as it should if not installed correctly, and the glass fibers can irritate the lungs, eyes, and skin. It is common in crawl spaces and basements.
• Spray Foam: Spray foam offers high R-values and creates a solid air barrier, but it is more expensive and requires an expert to install. It is a popular option for basements.
• Mineral Wool: It is fire resistant and offers soundproofing capabilities, but,  like fiberglass, it can irritate the lungs. It is most commonly used in suspended floors.
• Reflective Foil: Reflective foil reflects radiant heat, making it ideal for warmer climates, but it is not practical in colder climates without additional insulation methods. It is one of many methods used with suspended floors.
• Rigid Foam: Boards of foam insulation are ideal where space is a premium, but it must be cut to fit around pipes. It is a popular option for basements.

Warmup has developed its own insulation materials explicitly designed to work with heated floor systems. These included the Ultralight Insulation Boards, which are lightweight and easy to install. The design of the boards helps reflect heat upwards to maximize energy efficiency and is ideal for tile and stone floors. 

The Insulated Underlay for Foil Heater is also designed specifically for the Foil Heating System. This system is made of layered materials and provides ideal acoustic insulation. It is best suited for laminate, engineered wood, and carpeted floors.

3. Use Multiple Probes

While underfloor heating systems are controlled by their thermostat, the probe, or temperature sensor, makes it possible. These probes identify the room’s temperature through the heat from the floor. 

For the Foil Heating System, sensor probes are installed underneath the mat and placed at an halfway between two runs of the heater cable. 

DCM-PRO sensor probes should be centered between two element heating runs, at least 12″ into the heated area. It should not touch or cross any heating cables. If necessary, you can create a channel in the subfloor to ensure it doesn’t go above floor height, with a piece of tape over the communication wire to help hold it in place. It is recommended to have a backup sensor probe for every thermostat. 

4. Have a Dedicated Breaker with Two Conduits

When a circuit breaker trips, it is because too much electricity flows through the breaker, and it cannot handle the load. As a result, the breaker will cut off the flow of electricity until it is reset.

Having your radiant heating system on a separate circuit breaker will help ensure that your radiant heater will continue to work even if the main breaker is tripped. It also will ensure more flexibility if there is ever a need to work on the system’s wiring.

5. Let Your Thinset or Leveler Cure Fully

One important detail to understand regarding how to install floor heating is the difference between a thinset and a leveler. Both are common materials used to install radiant heating systems, designed with similar purposes but best suited to different jobs. 

Leveler, or self-leveling cement, is a mixture of cement, sand, and other additives that allow it to level itself out with little to no help. Leveler is commonly used on larger surfaces like concrete slabs and floors that aren’t level. It takes 12 to 24 hours for a self-leveling cement to cure.

Thinset is an adhesive made from cement, sand, and polymer, strengthening its bonding ability. It is typically used for smaller areas that are mostly level. It takes longer to cure, taking anywhere from 24 to 48 hours.

6. Verify Heat Output Warranties

Before you choose a radiant heat flooring manufacturer, you want to review their warranties. Look for a system whose warranty will protect the components; each component may have a different one. 

You aren’t just looking for a long warranty; it should have substance. Check what sort of support they are offering; do they offer a 24/7 call line? Even these small details make a difference. 

7. DIY-Friendly, but Licensed Electrician Required 

Despite looking complicated, installing electric radiant floor heating isn’t difficult, though it may require time and patience. You can find guides and videos to help you through the process of installing the system. The electrical components, however, should be left to a professional electrician who understands national and local codes. They can make the proper connections, install a dedicated circuit breaker, and handle other electrical needs.

Heated Floor Costs

The costs of installing heated floor systems depend on several factors. For an electric heated floor, cost considerations include the cost of the product, the size of the space, any supplemental materials you need to purchase, whether you install it yourself or hire a contractor, and the electrical work done by a professional. This doesn’t take the cost of flooring into account.

You can expect to pay a professional installer anywhere from $50 to $100 an hour to install electric heated flooring in your home. 

Frequently Asked Questions about Radiant Floor Heating Installation

How long do you have to wait to turn on the heat after radiant floor heating installation?

How long you have to wait depends on the curing times of the leveling cement or the thinset you use to secure the cables in place. Foil system products can be used immediately after installation. It is important never to turn on heating cables while they are exposed.

Can the floor probe or power supply cables be extended? 

If the floor probe or power cables aren’t long enough, they can be extended by a qualified electrician.

How do you install the factory joint if it is thicker than the heating wire?

Cut a channel into the subfloor for the joint to lay in to eliminate any height difference between the heating wire and splice. Once level, encapsulate it with thinset. Ensure the joint is level and secure; otherwise, the system may give out and no longer work. It will also void your warranty.

What radiant system is best to install in bathrooms? 

One option for a bathroom is Warmup’s DCM-PRO, which is designed to work with virtually every type of flooring, including stone and natural tile, the most common bathroom flooring materials. 

How thick can tiles be over a heating system?

While there is no limit to the thickness of the tiles, bear in mind that thicker tiles will make the system take longer to heat up.

Can I use Warmup electric floor heating as a primary heating source?

It depends on your home and how old it is. For older properties with lower insulation levels, it is best to use Warmup as a supplemental heat source. CSH Level 4 or higher homes could use Warmup as a primary heat source.

Is it possible to install underfloor heating without raising the floor height?

Yes! Warmup systems have been designed with a very thin heating element that is only 1.8mm thick. Our Foil Heater System is our one example and is ideal for floating floors like laminate, engineered wood, and carpet.

What thermostat options are there?

Warmup offers three thermostats:

The 6iE Smart Thermostat is the first underfloor heating controller that has a smartphone touch screen. It features weather-based Early Start technology to help maximize the system’s energy efficiency and significantly reduce your energy bill.  

The Terra WiFi Thermostat is a low-profile system with a high-resolution color display. It is simple to use and install and is compatible with all Warmup systems. The Terra thermostat uses SmartGeo technology to help automate heat control, reduce energy usage, and find the most efficient heat settings for your home.

The RFT thermostat is the most basic offering, with a simple programmable touchscreen interface. It comes with a floor probe. 

Getting Heated With Warmup Radiant Flooring

With over 25 years of experience in creating floor heating systems, Warmup has created some of the most reliable solutions for underfloor heating on the market. Our systems are easy to install, making them perfect for a DIY homeowner looking for heated floors on a budget. We also offer excellent warranties, with every component of a system covered. 
Contact the Warmup team today to learn about our different systems and find which is best for your home. You can also get a quick quote.