When I first moved into my new home, one of the most difficult decisions I had to make wasn't about furniture or wall color—it was about which carpet to choose for rooms equipped with underfloor heating. This detail may seem minor, but it had a surprising impact on both comfort and heating efficiency. I had to ask myself: between polyester and polypropylene carpet, which material works better with radiant heating?

I’ve had real, hands-on experience with both options in my own home, and through this article, I want to share my honest insights and professional perspective. Whether you’re dealing with an electric radiant floor or a hydronic system, choosing the wrong carpet could lead to poor heat flow, shortened carpet lifespan, or even safety concerns.

Understanding How Underfloor Heating Works

Before diving into carpet materials, it's essential to understand how underfloor heating systems operate. These systems generate warmth by running hot water pipes or electric coils beneath the floor surface. The goal is to evenly distribute heat throughout the room from the ground up.

However, this warmth must pass through any surface covering—including your carpet. That’s where things get tricky. The carpet must not insulate too much or block the heat, or else the system becomes inefficient. Therefore, selecting a carpet with the right thermal resistance (TOG rating) and material composition is critical for maximizing comfort and performance.

Polyester Carpet – Soft, Warm, but Not Always Compatible

I installed a polyester carpet in my master bedroom, which has an electric underfloor heating system. My first impression was overwhelmingly positive. The carpet felt plush and luxuriously soft underfoot, creating a warm and cozy atmosphere almost instantly.

However, after a full winter of use, I started noticing a few issues. Polyester is naturally good at trapping heat, which initially seemed like a benefit. But in reality, this trait caused too much insulation, creating a stuffy and overly warm sensation—especially when the heater ran overnight. I often had to lower the system’s temperature to keep the room comfortable.

Moreover, certain sections of the carpet began to show signs of compression and fiber fatigue. Polyester, while beautiful and soft, doesn't always handle sustained exposure to heat very well. Even though it's marketed as heat-resistant to a degree, I wouldn't personally recommend polyester carpets in areas with constant radiant floor use—unless you’re willing to monitor and adjust the temperature settings regularly.

=>>> Don't rush to buy a carpet! Read more to clearly understand the pros and cons of Polyester and Polypropylene carpets before deciding.

Polypropylene Carpet – A Safer, More Efficient Match for Heated Floors

In contrast, I tried using polypropylene carpet in my home office, where I keep the underfloor heating on throughout the day. Right away, I noticed better temperature regulation. The polypropylene fibers didn’t trap excessive heat, allowing the warmth to flow more naturally and evenly into the room.

Over time, the carpet maintained its structure, didn’t fade, and didn’t develop any noticeable dips or flattening in high-traffic areas. Polypropylene is engineered to withstand moisture and moderate heat, making it a great match for underfloor heating—especially in regions with cold, damp winters.

Another benefit was the lack of “mugginess” that I sometimes experienced with polyester. Polypropylene’s low moisture absorption made the air feel lighter and more breathable, even with the floor heater running for hours.

If you’re still unsure which to choose, I highly recommend checking out a polyester polypropylene carpet comparison to better understand the thermal behavior, longevity, and maintenance needs of each material in heated environments.

Heat Resistance and Safety Considerations

Based on my research and conversations with flooring professionals, carpets used with radiant heat should have a TOG rating of no more than 2.5. TOG stands for Thermal Overall Grade, which essentially measures how much the carpet resists heat transfer. Polyester often has a higher TOG rating, which makes it a bit of a barrier for warmth.

Polypropylene, on the other hand, typically has a lower TOG rating, allowing more heat to pass through efficiently. This difference might not seem important on paper, but in practice, it significantly affects how warm a room feels and how often your heater has to run.

From a safety standpoint, polypropylene also performs better. It’s more thermally stable, meaning it’s less likely to deform, shrink, or change texture when exposed to long-term, low-grade heat. Polyester fibers are more prone to subtle warping, especially if the heat settings are left too high for extended periods.

Personal Experience After One Winter

After trying both materials through an entire cold season, I can say with confidence that polypropylene is the smarter choice if you're using underfloor heating. Not only did it provide even warmth, but I didn’t have to constantly adjust settings, worry about wear and tear, or feel uncomfortably hot when relaxing on the floor.

Polyester certainly has its advantages—it’s soft, visually appealing, and comfortable for barefoot walking. However, the drawbacks in thermal performance and long-term durability in a heated setting made it less practical for my needs. Unless your underfloor heating system is only used occasionally or at very low settings, polyester might not hold up as well over the years.

=>> Want to know which carpet is better for your needs? Click here to explore the comparison between Polyester and Polypropylene from KATAmats.

Final Thoughts – Choose Compatibility Over Aesthetics

In the end, when you're choosing carpet for a home with radiant floor heating, compatibility matters more than just softness or color. I learned firsthand that polypropylene offers the best balance of heat conduction, durability, and comfort. It keeps your system efficient while ensuring your home stays warm without overheating or damaging your flooring.

So, if you’re at a crossroads like I was, I encourage you to dig deeper into the technical aspects of carpet materials. And don’t overlook the importance of real-world experiences and insights. A beautiful carpet is only worthwhile if it works well with your lifestyle and heating needs.

And again, for a more thorough breakdown of differences, I recommend checking out a polyester polypropylene carpet comparison article to help guide your final decision.