Radiant Floor Warming Design

Radiant floor warming is a wonderful addition to any living or working space. The warm floor makes the space the most comfortable in the entire building.  Designed to provide years of trouble free service, high quality floor warming systems are designed to last substantially longer than the flooring covering itself.  Given their long life expectancy and the repair/replacement expense incurred if the heating element or tubing gets damaged or, improperly installed, a significant amount of time should be devoted to the design, product selection and installation of radiant floor warming system.


Designing a radiant floor warming system is relatively easy, provided; a few simple rules are followed.  Listed below please find a list of simple rules for designing a radiant floor warming system:

  1. The design should deliver 7.5 to 12 watts (25 to 41 Btu) per square foot to effectively warm floors.  The National Electric Code limits the maximum heat that should be installed in the floor to 15 watts per square foot.
  2. Only the floor areas where the occupants will stand or walk require warming in order for a radiant floor warming system to effective.  Radiant space heating however may require different coverage to satisfy the requirements of a Heat Load or Loss Calculation.
  3. Proper spacing of the heating element or tubing is very important because the human foot is very temperature sensitive and even a few degrees temperature differential will be noticed.
  4. The spacing of the heating element or tubing will vary depending upon the R-value of the insulation below the sub-straight, the sub-straight material, what ever will cover the heating element or tubing, and the floor covering.
  5. Keep the heating element or tubing away from the base of the toilet and/or bidet because the wax ring that makes the drain water tight may be compromised by the heat.
  6. Determine if it is desirable to heat the shower floor or the shaving bench.
  7. Avoid one size fits all products that require the project to adjust to the radiant floor warming product rather than the other way around.

Once the design is complete the best products for that design can be determined and a final selection made.

Product Selection

Often times, product selection occurs simultaneously with the design process.  The nature of the design process helps focus on the advantages and disadvantages of different technologies and thus helps determine which are best suited for the project.  At the very minimum the design process should help eliminate most of the competing radiant floor heating technologies from further consideration leaving less than a hand full for further evaluation.

Remember number 7) under design and do not allow the product to control the project.  Since many competing products are available and they differ in technology, quality and warranty coverage, most buyers are well served by contacting a radiant floor warming professional to assist in determining which is best suited for their needs and their project.


More difficult than design and product selection (but equally deserving of attention to detail), is the proper installation of the radiant floor warming system.  As a matter of fact incorrect installation and/or product damage during installation are the two leading causes of problems in the radiant floor warming industry.

No doubt the best way to insure proper installation is to choose a product made by a manufacturer that has a comprehensive installation manual, offers unlimited technical support and has been in business for more than a couple of years.

Steven Bench is Managing Member of Heatizon Systems a leading manufacturer of radiant snow melting, floor warming, roof snow and ice melting, pipe warming, and radiant space heating products located in Murray, Utah.