Radiant floor heating systems are luxurious yet practical additions to new homes that are also making their way into older homes through major floor renovations. Radiant heating is arguably the most comfortable and efficient home heating system. It is invisible and doesn’t make any clanking or hissing noise. You cannot even tell it is there except for the blanket of warmth it provides.

The efficacy of a radiant floor heating system largely depends on the floor covering you put on top of it. There is a wide range of flooring options that you can choose from for radiant heating systems. The best flooring for radiant heating systems will warm up fast and retain the heat for a long time.

Best Flooring for Radiant Heating Systems

You can estimate whether the flooring will be suitable for the radiant floor heating system by touching it. If the flooring is cold to touch on its own, it indicates that it’s a good conductor of heat — therefore, it will be the best flooring for radiant heating systems. Also, it should be thin and hold well to water and heat damage.

Ceramic tiles are the most effective flooring to use with radiant floor heating systems. It is an excellent conductor of heat and retains heat between system cycles to keep the temperature uniform. The same properties also make natural stone and polished concrete perfect for radiant heating.

Other flooring materials, although they are poor conductors of heat, such as laminate, vinyl, luxury vinyl, wood, and carpeting, can be used with radiant flooring. But keep in mind that putting insulating materials on top of the underfloor heating system means the heating cycles are lengthened to transmit the heat through them to reach the floor’s surface. Thick carpets, rubber, and glued-down installations are not ideal for radiant heating.

Ideal flooring properties for Radiant Floor Heating

• Lower thermal mass
• Higher conductivity
• Ability to retain heat
• Low thickness

Heat-up times for different flooring materials

The heat-up time refers to how long it takes for the flooring material to warm up. The thermal mass and conductivity of the material dictate the heat-up time, which varies with different materials. Even though lower thermal mass is ideal for radiant heating, keep in mind that it also means it will cool down faster.

Porcelain or Ceramic Tile: Best conductor of heat

Porcelain and ceramic tiles are the best materials to use with the radiant heating system. Ceramic has excellent heat transfer properties and a thin profile. Additionally, tiles do not contain any organic compound that will rot or degrade if the hydronic heating system leaks. The tiles heat up rapidly as soon as the heating cycle starts. However, the high thermal conductivity also means it doesn’t retain heat for long once the system turns off. Another pro of porcelain and ceramic tiles is they do not expand or contract minimally with heat and do not warp or crack easily.

Ceramic and porcelain tiles are affordable and easy to maintain. They are also highly durable and can be installed in any part of the house, including bathrooms and kitchens. Porcelain tiles are also highly waterproof, having a water absorption rate of 0.5 or less. They can be put in bathrooms with electric radiant heating systems, so you never have to step on the cold floor coming out of the shower again.

Natural Stone: Luxurious alternative to ceramics

Natural stone is a natural fit for radiant heating systems. Natural stones or aggregate stones have a similar thermal profile to ceramics and porcelains while being thicker in comparison. Although the higher thickness means it takes the heat longer to reach the surface, it adds to the benefit because it also means better heat retention. Natural stone stays warm for longer to keep the surface warm even during the off cycles.

Although some natural stones cost a fortune, they add value to the home. They are incredibly durable and easily last over 100 years. Most natural stones easily outlast the building and only need replacing if they become too dull and dingy due to improper care.

Polished Concrete: Suitable for electric and hydronic heating systems

Polished concrete is a highly conductive flooring material that heats up rapidly when the underfloor heating system starts running. It is also waterproof. So, you can use it safely with hydronic radiant floor heating without the risk of water damage if the system leaks. Polished concrete also allows custom thickness, so you get different thickness options that combine the best of both worlds — thermal conductivity and heat retention.

Polished concrete is highly durable and affordable. Although it was previously widespread in commercial spaces, polished concrete is now a stylish choice for residential purposes. Its high gloss finish and seamless look are perfect for modern interiors. However, keep in mind that integrating underfloor heating with polished concrete is most reasonable during a new build rather than later.

Laminate: Thin material for fast heat transfer

The thinness of laminate makes it an excellent choice for underfloor heating, as it can transfer heat to the surface almost instantaneously. However, laminate flooring cannot handle very high heat — meaning you can run your heating only up to a safe temperature. Most manufacturers recommend a maximum of 85 degrees Fahrenheit to avoid heat damage. Additionally, it has a soft and warm underfoot that gives you a cozy feel even in lower heating.

Laminate is sensitive to water damage. So, moisture can damage the flooring if you choose hydronic radiant heating. Or even leakages in the system can cause water damage to the laminate. So, it is used chiefly with electrical radiant floor heating. As laminates already have warm underfoot, most people only use heating under it in extremely cold areas.

Vinyl: Safe to use with radiant heat systems

Vinyl floors are composed of PVC (vinyl), fiberglass, plasticizers, and a thin print layer on top and sometimes with an addition of cork or foam backing. All of these materials tolerate heat well up to 85 degrees Fahrenheit. However, depending on the manufacturer and the prints, keeping the heating below 80 degrees is recommended to prevent color degradation or shrinkage.

You can use vinyl sheets, planks, and tiles with radiant heat systems. Luxury vinyl tiles and planks also work well with radiant heating. Additionally, LVT for bathrooms is a popular choice for its water resistance. You can put electric radiant heating underneath to keep the bathroom cozy in cold winters.

Engineered Hardwood: An improved hardwood alternative

Between solid hardwood and engineered hardwood, engineered works better with radiant heating because it does not react as quickly to temperature changes. Engineered hardwood is thinner than solid hardwood, allowing better heat transfer. It consists of a thin layer or a “veneer” of solid hardwood bonded over a plywood substrate. The plywood gives it a stable and solid core.

However, wood is a poor conductor of heat. It means the heat from the electric wires or hydronic pipes will not transfer as quickly to the surface as it would with thinner and more thermally conductive flooring. But the flooring will still warm up when the heating runs long enough and stay warm for longer.

Solid Hardwood: Thin and narrow floorboards are more thermally conductive

Although not an ideal choice for radiant floor heating, solid hardwood holds the top place for flooring choice overall. Therefore, you can still work around its poor conductivity and highly insulative properties. Use narrower floorboards as they allow more spaces for expansion and contraction with temperature changes. If you are using anything wider than four inches, consider extra acclimation.

Quarter-sawn and rift-sawn hardwood is also preferred over plain-sawn as they are dimensionally more stable. North American oak, American cherry, and American walnut are appropriate for radiant heating. Avoid extremely dense hardwoods that rank 1,375 or more on the Janka hardness scale.

Carpet: Thin carpets with dense padding are preferred

Carpets have excellent insulating properties — making them unfit for use over radiant floor heating systems. You can still put them over radiant heating but keep in mind that it will reduce the system’s efficiency. You might need to turn up the thermostat higher than you would have to for hard flooring.

Use thin carpets with dense padding to drive the heat flow to the top and hold it much longer. Although carpet reduces the efficiency of underfloor heating, carpeting all by itself is warmer than hard floors. Therefore, it does not require turning on the heating all the time or in the warmer parts of the house — which can eventually save up on the electric bill.

What flooring is not suitable for underfloor heating?

Glued-down floors: Any flooring installed using adhesive is a poor choice for radiant heating as the bond will come off in the heat, and the installation will become unstable. Tongue-and-groove or click-and-lock installations are more suited for radiant heating.

Rubber flooring: Rubber flooring cannot tolerate high heat and might melt into the subfloor over time.

Thick carpet: It goes without saying that a thick carpet will make underfloor heating less effective as the heat cannot even pass through it. Only use thin rugs with thick padding if you want to put carpet on top of radiant heating systems. But remember, any carpet, regardless of the thickness, will take away from the efficiency of the radiant floor heating system.

Carpet tiles: Carpet tiles are glued down to the subfloor, which can come loose in heat. Avoid carpet tiles as the carpet is not ideal for underfloor heating, and glued-down installation is an even worse combination.

Choosing the best flooring for a radiant heat system is crucial as it will ensure the maximum efficiency of your heating. Otherwise, you will only crank up the electric bill without even benefitting from your investment.