The Evolution of Tile Substrate Innovations

A fresh look at using electrical heat under tile floors is my excuse for following a fascinating story about technological innovation and competition in this field.

BY JON EAKES

Heated tile floors have been a wonderful luxury for years but, for much of the country, where electricity is expensive, we tend to only look at this option if we have hydronic heat available. Pre-sized electrical mats have always presented many design limitations. Because of innovations, site-shaped electrical layouts are making electrical heat a growing option, including small installations in regions where electricity is expensive.

Circa 1987: Schluter-DITRA
Schluter Systems, the absolute leader in tile support systems, brought the Schluter-DITRA membrane into Canada from Germany. This is the now-famous recessed square grid that adheres to the floor and adheres to the tiles but allows for movement between the two-called an uncoupling membrane. No more cracked tiles and the possibility of using one less layer of plywood in most installations because of the structural rigidity it gives to the floor. With a little more work on the edges of the membrane, the whole system is even waterproof. This innovation sounded the end of the floating concrete slab that was traditionally used for under-tile support of high-end entranceways and bathrooms.

Circa 1998: Schluter-Bekotec
Most of Europe provides radiant heat with hydronic tubes, as does most of Canada. So Schluter North America decided to import BEKOTEC, its studded polystyrene screed panels for easy layout of heating tubbing and stress removal, still covering the assembly with the DITRA. This was a breakthrough for large commercial and industrial heated floors. It was now possible to bypass the tedious tying of tubing to rebar, plus the heat source was located directly under the tiles rather than buried in the concrete slab giving far faster response times.

Circa 2004: FlexTherm Green Cable & Snap-in Gauges
FlexTherm, a Quebec firm and a major player in the electrical heating cable industry, took a giant breakthrough step in creating a floor heating cable that gave off practically no electromagnetic radiation. They call it Green Cable.
That was a time when no one admitted that the medical problem of electromagnetic hypersensitivity existed and most of their own products innocently blasted out large quantities of EMF radiation, just like everyone else. How do you market something that condemns most of your own products and that most doctors say is nonsense? They persisted, and today all of their products that are installed in close proximity to human activity use that non-radiating Green Cable. Just think back to the advertising photos of children playing on that warm tile floor that every electrical floor heating company published in those days.
FlexTherm's sales success of the Green Cable follows closely the evolution in the medical field where electro-hypersensitivity is becoming a recognized medical problem in Europe, where several hospitals in Canada have whole sections devoted to this environmental medical condition and where both the population and the courts are beginning to force the Canadian medical establishments to take a second look at this problem. FlexTherm is proving to be a good surfer, catching the wave right at the crest.
Schluter DITRA and FlexTherm were often used together, although they fought over which one should go on top. The most important part of that debate was to not put holes in Schluter's waterproof membrane. But with the two, you could combine electrical heat and uncoupling together in one assembly.

Circa 2009: FlexTherm FlexSnap-Installing with a Broomstick
FlexTherm got more active in its wire attachment systems, bringing out its very unique FlexSnap. This is an open plastic grid, made of 1'x1' interlocking squares. It is screwed down to the floor on the 1x1 corners and then the cable is incredibly quickly "snapped" into place with a rolling insert head on the end of a broomstick. The grid pattern ended up giving enough rigidity to the floor to eliminate that extra plywood layer in most circumstances, just like the Schluter DITRA membrane. It does not provide uncoupling or waterproofing, but it does make custom layouts of electrically heated floors even easier to install.

Circa 2014: Schluter-DITRA HEAT
Schluter got into the electrical heating business with its own special DITRA HEAT membrane. Although using standard floor heating cables, it introduced a waterproof uncoupling membrane that was specifically made to easily embed the electrical heating wires, now directly competing with FlexTherm.

Circa 2014: FlexTherm Green Cable XL
Recognizing that its core business was making the Green Cables, FlexTherm brought out FlexTherm XL, a Green Cable specifically sized to fit into Schluter's increasingly popular DITRA HEAT membrane.

Circa 2015: Schluter Expands Cable Lengths
After taking a close look at the Canadian market uptake for in-floor electrical heating and seeing FlexTherm sales of small 30' cables for use in Schluter membranes, Schluter has just announced enlarging the variety of cable lengths available for its system, bringing in cables short enough to heat as small a space as 10 square feet, something that hydronic heating just cannot do efficiently.

Often in this industry we see the emergence of copycat products competing on price with lower quality. This was a rare opportunity to follow the competitive evolution of two top-notch companies who have intertwined quality innovations over time, moving heated tile floors step-by-step closer and closer to installation and performance perfection. Find them at FlexTherm.com and Schluter.com.

Montreal-based TV broadcaster, author, home renovation and tool expert Jon Eakes provides a tool feature in each edition of Home BUILDER.
www.JonEakes.com