There’s nothing like the comfort of stepping onto a heated floor, especially during cold mornings and chilly nights. And yet, stepping onto a soft, cozy rug is a luxury, too. Is it possible to lay carpet on top of heated flooring? And more importantly, is it safe?
The answer is yes, heated floors can go under carpet. Armed with the right information, a little bit of planning, and appropriate materials, you can safely enjoy the best of both flooring worlds. Contrary to the myth that carpet will trap heat rising from the floor, carpeting actually provides the same temperature of any heated floor. Plus, the right underlay will give the carpet a little cushion, doubling the luxury of an in-floor heating system.
It makes sense that whenever heat and textiles are in close proximity, safety hazards and product performance could be of concern. But continue reading to understand why heated flooring under carpet is a sound option and an equally solid investment for years to come!
You can be assured that all in-floor heating products have withstood multitudes of tests, undergone rigorous studies, and have been widely used by electricians for nearly 45 years. Nationwide standards ensure product safety through independent testing agencies. Additionally, cables used for in-floor heating are engineered to protect wires and specifically designed to eliminate any possibility of electric shock.
It is helpful to know that through the use of a thermostat, consumers can adjust and monitor the temperatures coming from their heat sources. And since in-floor heating systems are restricted to a maximum temperature, homeowners can be certain that their flooring will never heat up to a dangerous level.
Of course, as always, contacting a professional electrician who can provide more detailed information about any safety concerns is a good idea, especially if it can give you peace of mind.
How Does In-floor Heating Work?
In-floor heating, also called radiant floor heating, is most commonly available in two formats. The first is a hot water system where tubes are placed under flooring with hot water running through them, warming the floor. The second option is an electric system where wiring is installed under the floor and, connected to a power source, will warm the floor using electricity. Both systems are efficient and provide consistent heat evenly across floors, though they also have different pros and cons.
Water-based systems, also called hydronic floor heating, are typically the most efficient option over the course of time; however, installation can be complicated and expensive as a boiler, pump, and gas lines are involved. These systems are also best installed during the home building process, though retrofitting it in an existing house is possible.
Electric floor heating, on the other hand, is easier to install and therefore less expensive to set up. It warms floors--and even rooms--just as well as hydronic systems, but depends upon electric power to run, and electricity can be expensive as well.
Is Under Carpet Heating Effective?
Yes, provided that the layers between the heat source and carpet are sufficient conduits for heat. The warmth from your underfloor heat source should pass as quickly as possible to the surface you want to warm. Therefore your carpet, including its backing and padding, should have a low level of thermal resistance, making it easier for the heat to rise.
Choosing the Right Carpet for Your Heated Floors
Luckily, carpets and padding have a thermal resistance rating (R-value) which takes into account the fiber, yarn type, pile height, and weight of carpet, as well as the thickness and density of padding. HVAC professionals recommend that your carpet R-value be between 1-2 and, with padding, should total no more than an R-value of 3. The Carpet and Rug Institute’s study created these dependable values and make evaluating carpeting and padding easier for consumers.
Consider what type of material is on the reverse side of your carpet, too. A felt-back carpet will block heat and potentially affect the finish of your floor. A better option is a hessian back which wears longer and is typical of most carpet backing.
Does Underfloor Heating Require Special Underlay?
Special underlay is sometimes needed and sometimes not. It’s best to contact the manufacturer of your in-floor system to determine if there are any specific flooring requirements. However, underlayments, typically made of foam, rubber, or cork, can be a worthwhile investment and are often used to absorb sounds, repel moisture, and ensure the floor is smooth and level.
How Long Do Heated Floors Last?
With proper installation and regular maintenance, an in-floor heating system can last upwards of 25-30 years. In comparison, a standard furnace needs replacement every 10-20 years, suggesting that in-floor heating is a significant and valuable investment.
You can transform your floors into a cushioned, heated luxury, too, by using a standard electric heating mat.
How Do You Install Under Carpet Heating?
- Contact an electrician to make sure adding this new heating element won’t overwhelm your electrical system. It’s possible that you may have to add additional circuits to provide more power to your home.
- Purchase an electric underfloor heating mat kit, made specifically for under carpet use. These kits are widely available at any home improvement store or ordered online directly from a brand distributor. Be sure to measure the size of the floor space you want to heat and purchase material accordingly.
- Clear your subfloor from any debris, nails, staples, or screws. Use caution with sharp tools to avoid accidental punctures.
- Install the appropriate carpet padding, ensuring that its R-value is less than 1, is no thicker than 3/8“, and has a density of 6 lbs per cubic foot. This is your insulated underlay.
- Unroll the heating mat and adhere it to the underlay, following the manufacturer's directions.
- Before covering the floor with your carpet, determine the route of the heating element’s cords to the power supply. Also, consider where the cords of your electronics will run. You may have to cut out a small piece of carpet at the edge to accommodate power cords.
- Connect the thermostat according to the product’s instructions.
- Unroll and fit your carpet over your newly-installed in-floor heating system, again being careful with any tools or sharp objects that could damage wiring or the mat.
- That’s it! Now you can relax, feeling confident that your feet will always be toasty and warm.
Hopefully, this information about carpets, in-floor heating mechanisms, and how they work together will demystify the process of radiant heat installation.