Guest Post - The joys of radiant floor heat

In many parts of the U.S. and Canada, cold temperatures are already settling in. This is delightful when you're relaxing in front of your fireplace with a cup of hot cocoa, but not so much when you step onto cold bathroom tile first thing in the morning.

Thus was born the inspiration for this guest post! When David Tiefenthaler. who writes for the very informative Radiant Heat Reviewer blog, approached me a few months ago with this topic, I replied with a resounding yes. I had experienced the joys of radiant floor heat in a German hotel last January on my LivingKitchen trip and absolutely loved it! If I'm ever forced to live in a cold climate again, I would absolutely demand radiant floor heat. As most of my design projects have been in warmer climes, I haven't had the opportunity to specify it. That's why sharing David's expertise on this topic for my cold climate readers was such a welcome opportunity. Here are his insights into the why, what, how and how much of this technology for your home.

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What is radiant floor heat? Exactly as it sounds, a floor is heated to radiate warmth from below for the comfort of any people and pets in the room. Radiant systems use either electric cables or heated water embedded beneath the finished flooring to do their job.

Radiant heating duplicates the feeling you would get if you were to walk barefoot on a floor that’s been warmed by direct sunlight for several hours. People who have it in their homes often walk around barefoot – even in the middle of winter! It’s a great option for cold climate residents or winter home owners.

The most common application of radiant floor heat is to install it under tile floors during a bathroom or kitchen remodel. The system is linked to its own thermostat, separate from the home’s forced air unit. For smaller rooms like a bathroom, adding an electric radiant floor heat system only costs about $500 to $1000 total for labor and for the materials. You would also have to choose a thermostat to go with it; always choose the programmable option, even though it is more expensive. With this system, I strongly recommend hiring a licensed electrician to connect the thermostat to your home’s electrical system.

Tile floor with electric radiant heat by ThermoSoft embedded in thinset

Some consumers worry that an electric-powered system will increase their utility bill astronomically. This simply isn’t the case. Thermostats that are linked to radiant floor heat can be programmed to heat up only when needed. For instance, if you get up for work at 6 a.m., the thermostat can be programmed to heat up the floor at this time of the day. Instead of waking up to ice-cold tile under your toes in the kitchen or bathroom, you’ll be greeted to the toasty touch of warm tiles. With a programmable thermostat, you will enjoy this luxury for about $10 to $20 per month extra on your electric bill.

You can use radiant floor heat to heat your entire house, but this is much more complex to install in a pre-existing home. For larger areas, like whole home remodels or new home construction, hydronic radiant heat is primarily used. This is because water can be heated with natural gas or oil-fired boilers, and these energy sources are less expensive to use than electricity.

For new home construction, long loops of radiant tubing are typically embedded in the concrete slab. A boiler heats up the water, which heats up the slab, which heats the finished flooring above it. In the most efficient applications, the tubes are included in the subfloor, rather than the slab below.

Homes and buildings with hydronic radiant heat on floors above grade level use aluminum plates strapped to the subfloor. The aluminum acts as a great conductor of heat, which in turn heats up the whole floor. Some products, like Warmboard, actually have aluminum built into the top layer of the subflooring. This puts the heat closer to your feet and requires even less energy to heat the floor.

A cross section of Warmboard subflooring with PEX-AL-PEX tubing in the aluminum channel.

No matter what choice you go with, the one constant is the luxurious comfort created by radiant floor heat. To paraphrase an '80s song, “It’s like walking on sunshine.”


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David Tiefenthaler writes for Radiant Heat Reviewer to help consumers understand their options when considering different forms of radiant heat. He is a Do It Yourselfer and is always investigating the most economical and innovative ways to incorporate radiant heat in a home or building.