Lukas Smith, a framer by trade, is building a 3,100-sq. ft. house in southern Ontario and plans to install a radiant-floor system in the basement slab as well as the first and second floors. The house will be built with structural insulated panels (SIPs) and have R-values of 33 in the walls and 50 in the roof.
With that as background, Smith poses three questions in his Q&A post: should he pour a layer of gypsum-concrete over the tubing; can he run the system from a hot water heater instead of a boiler; and what is the best way of providing air conditioning?
The discussion is the subject of this week’s Q&A Spotlight.
First, the flooring choices
Above-floor radiant tubing can be installed in aluminized floor panels such as Quik Trak and then covered with finished flooring. Alternately, the tubing can be covered with a layer of concrete, either conventional concrete if the floor framing is designed for the weight, or a lightweight gypsum concrete.
Lucas refers to this second option as an “over-pour,” and says some contractors have told him not to pursue it because the house is so tight. “Others say I would be wasting my money not doing it,” he adds.
But David Meiland thinks Smith is talking apples and oranges: “I don’t see what an ‘over-pour’ has to do with the house being extremely tight,” Meiland says. “You are either going to install tubing using a product like Quik Trak, or you’re going to pour gyp or lightweight over it. In my opinion you ought to review your choices of floor coverings and see which way that pushes you. I personally like gyp but it’s harder or impossible to install some types of flooring over it. “
Will a water heater…
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