How to Build a Heated Floor

Heated floors were once exclusive to newly-built luxury domains. But as with most things, high demand has forced the technology to evolve quickly, making them more readily accessible. Richard English, owner of All Island Radiant in Smithtown, outlines the best way to build a heated floor system from the ground up.

Long Island Pulse: What are your options for radiant heat flooring?
Richard English: There’s hydronic and electric. Hydronic is circulating hot water. We stay away from the electric because we’ve run into problems with the cables burning out. It is cheaper and there are some DIY options at the big box stores, but you have to rip up the whole floor if there are any problems. With the radiant system, the water circulates through plastic tubes that will last a lifetime and there’s nothing that can burnout.

Pulse: What type of flooring works best with radiant heating?
RE: Ceramic or porcelain tile is the best because you heat the thermal slab (or mortar for tile) and it will stay warmer longer. Natural stone is perfect. I always tell people radiant heat doesn’t know which way to go, you have to tell it. By putting a good R-value material underneath, once it heats it will maintain that warmth. We do a lot of jobs with wood, and it’ll heat quickly and it is a successful application, but it loses heat just as fast. We have different applications where we can put it in the joist spaces and use heat transfer plates that the tubes snap into. We can go underneath the subfloor, put it in, insulate it and the heat goes directly up.

Pulse: How is the heat regulated?
RE: The best way to design any radiant heating system is with an indoor/outdoor sensor. This means that there’s an outdoor sensor and there’s a floor sensor inside and the two talk to each other saying, “Ok, it’s a forty degree day outside today, inside you only need one-hundred degree water to heat the house.” Your ultimate heat savings are unbelievable, plus your comfort level is in check—never too hot or cold.

Pulse: How are the systems improving?
RE: Everybody is getting more energy efficient using energy efficient circulators that are lower wattage. The most efficient way to design a radiant floor is with constant circulation always moving the water and letting the outdoor sensor raise and lower the temperature. And with newer Electronically Commutated Motors everything is getting greener. Every system I design I insist on using outdoor sensors because it lowers the heating bill by using lower water temperatures. If the house is well insulated it saves up to 45-50 percent on heating costs.