With the popularity of radiant floor heat and sales rising each year, more and more people are installing radiant floor heating systems.

Radiant Floor heat creates some questions when first starting, in this article series, we will explain the key points of radiant floor heat and give you the confidence to start including radiant floor heat in your projects.


What information is needed to get a project started?

The design needs to be done by someone who has a background in the business. I won’t bore you with the details of design, but listed below is an theoretic example of what information a designer would need to get you started.

  • Dimensions of building; width, length and height
  • What is the purpose of the building (example: farm shop, body shop, etc.)
  • Any obstructions, such as division walls, trench drains, hoist, mechanics pit, etc.
  • How many concrete pours?
  • Type of fasteners (zip ties, staples, screw clips)
  • Heat Loss; R-values, door sizes, window sizes, inside temperature, etc.

With the above information, a designer can suggest loop layout, on center spacing, loop lengths, pump sizing, boiler sizing, etc.

Are concrete contractors installing radiant floor heat?
Yes, once the proper design work is done, anyone can install radiant floor tubing. I always say 99% of the brain work is done at the designer’s desk.

There are several advantages for the concrete contractor to get involved:

  • Taking control of the time frame of the concrete pour. No need to wait for the plumber to show up!
  • Sell the radiant floor as part of the concrete package!
  • Create a new profit center. You make money selling the product, you make money installing the product, and you keep your crews on schedule.

What kinds of problems have occurred with radiant floor heat?

Over the years, I’ve mainly ran into design type problems. Very rarely have I seen an installation problem. Some of the design problems I’ve encountered are:

  • Too long of loop lengths.
  • Too small of pumps or heat source.
  • Incorrect on center spacing of the loops.
  • Layout patterns not matching the building.
  • Pour quality products. (I find it ironic that when an expensive building is being built, and someone wants to save $300.00 on floor tubing that is encased in concrete.)
  • A few people have cut or drilled into their loops. Most of those have carefully chiseled concrete away and fixed the tubing with a coupler.

One installation problem that I was told about was when an installer did not use enough fasteners with a Pex tubing. The Pex tubing was springing up to the surface as the power trowel was going over the pour. The trowel cut the tubing in several places – not a pretty picture!

Final thoughts/ Summary
Hydronic Radiant Floor heat is here to stay, and has many benefits over conventional heating systems. It is pretty simple when starting a project. You need to consider insulation under and around the perimeter, weather you want to use Pex-Al-Pex or regular Pex, and you need to have a design person involved.

In a previous article, I explained the importance of an oxygen barrier tubing, and why hydronic floor tubing is a better option than electric mats.  Hydronic radiant floor heat is simple to install once a designer has done his or her job correctly.

We also talked about why concrete contractors are getting more involved with hydronic radiant floor heat. So this should equip you with the confidence to talk radiant floor heat with your customers and add additional profit to your bottom line.

Notice the Pex-Al-Pex staying flat on the Styrofoam. Air test is on tubing and ready for the concrete.



By Les Graham, president and owner of Radiant Outfitters based out of New London, Minnesota. Graham has 24 years of experience in radiant floor heating and has certified with the Radiant Panel Association.

Radiant Outfitters, a wholesale distributor, offers complete design service and product, partnering with all types of contractors that install radiant floor tubing. For more information, call 877-855.2537, or visit www.radiantoutfitters.com.