Radiant Heat Systems for Tile: Not Just for Minnesota Anymore

An installer beats electric mats into thinset mortar to create better bond to substrate.


Kathleen Scranton of EGS Easy Heat (www.easyheat.com) was given the unenviable task of providing the final presentation at Total Solutions 2006, the annual educational conference hosted by the National Tile Contractors Association. Despite the obstacles, Kathleen's message was heard loud and clear by all of us in the audience. Radiant heated floors are exploding and are providing a dual benefit of adding value to the homeowner and profit to the distributor and installation contractor. It doesn't get much better than that.

Although radiant heat floor systems have been around for many years, consumption in the United States pales in comparison to some other leading countries in per capita use of the product in conjunction with ceramic tile and natural stone. Thanks to a strong, concerted marketing effort by many radiant manufacturers and a receptive audience from the design and building industries, consumers are now the beneficiaries of these fine products that add comfort and value to the home. The result is a staggering increase in the use of radiant heat throughout the United States, not just in markets of cold weather climate.

John Cox, NTCA First Vice-President and owner of a high-end residential contracting company in warm and humid San Antonio, Texas, is a perfect example of this changing trend. "Several years ago, I saw an opportunity in my market to promote radiant heat for certain installations in San Antonio. It is more popular than you might think. We sell a good bit of heated floors here," says Cox. "The winters in the south can be colder than one might imagine, and the luxury of a heated master bathroom floor can be as popular with the consumer here as anywhere else."

Cox, who is a certified Nuheat (www.nuheat.com) installer and dealer, says the profit added to his business is an added benefit. "Installing ceramic tile and natural stone the right way over electric radiant heat is a skill we have worked to perfect, and we expect to be paid for it. I haven't had one customer complain about the price once they experienced its value. It is one of those rare instances where we can add significant profit to our bottom line on a project and make the customer feel darn lucky they made the decision to have heated floors installed."

When you think about it, it only makes sense that traditional warm weather states will start to embrace radiant heated floors in certain areas. In the hot summer months the system can be turned off, and turned on when the winter cools the temperatures. In addition, in many states that one would consider to be warm weather areas, there are geographic regions exposed to cooler climates. Arizona, Texas, California and others fit this bill.

It is important to use the proper gauged trowel for the thinset to be applied over the electric radiant system prior to installing tile.
In many northern states, hydronic tubing sales, heating the entire home with hot water, have experienced phenomenal growth. Ceramic tile can be successfully installed over these tubes in several ways. The TCA Handbook for tile installation recognizes details for cement, poured gypsum, and new in 2007, poured self-leveling cementitious underlayments for concrete subfloors. In addition, methods for poured gypsum and poured cementitious self-leveling underlayments over a wood subfloor meeting requirements set forth over a 16" joist spacing are detailed. Consult the 2006 TCA Handbook and wait for the new 2007 edition to be published to get these specific details. More importantly, consult with the manufacturer of the installation materials company of preference to properly document written instructions for installation over hydronic systems. Some systems may require a crack isolation or waterproof membrane to be installed prior to applying the thinset for tile installation.

In the warmer climate states, spot warming of electric radiant heat companies is the product of choice. Companies such as Easy Heat, Nuheat, SunTouch, (www.suntouch.net), Warmly Yours (www.warmlyyours.com) and others have partnered with NTCA to provide education for the proper installation over their systems. Whether they come in mats, rolled goods with electric cables strategically placed in the mesh, or cables attached to the substrate, these products, when properly installed, can add significant value to the project.

In 2003, the TCA Handbook added details for electric radiant heat over concrete (RH-115-05), specific backerboards over a wood subfloor (RH-135-05) and over a double wood system over 16" on center joist spacing. (RH-130-05). In 2005, a method recognizing the same installation over 19.2" spacing was approved (RH140-05) as was poured gypsum underlayments over a double wood floor with 16" on center spacing (RH122-05) and cementitious self-leveling underlayments over a concrete subfloor (RH-116-05). It is vital that you carefully read all of these approved methods and get written installation instructions from both the electric radiant heat company and the installation materials manufacturer. An example of why this might be crucial is that the two installation instructions may conflict, putting responsibility squarely on your shoulders.

The message coming from the methods being approved in the TCA Handbook is clear. Ceramic tile is being successfully installed over certain substrates utilizing electric radiant heat systems. The caution is to tread carefully and do your research. Partner with the installation materials manufacturer proactively ahead of time. Get written recommendations for each different type of electric heat system. One size does not fit all.Read carefully what your role is and what is the responsibility of the electrical contractor.

New in 2006, the NTCA issue its first document for our Reference Manual problem-solving guide for members. The goal was to create several of the main things that go wrong with an installation over commonly used electric radiant heat systems. The NTCA Technical Committee will continue to work on this document, but some of the common jobsite mistakes are included in diagram E-31.

All ceramic tile installations involve careful planning and attention to detail. Electric radiant heat system installations are no different. Doing it right the first time remains vital to our industry. Use this problem-solving guide proactively when you are presented the opportunity to provide electric heated floors to your customer.

It is no secret that our industry continues to grow by leaps and bounds. Electric radiant heat is a key component that has helped to spur tile sales in areas some consumers had been hesitant to consider before. And it has barely scratched the surface of its potential. I urge you to get on board and embrace this popular and profitable trend.