Now your making progress! Nothing a nice secure, flat surface to stumble and fall on. LOL The in floor heating systems usually have an aluminum that plate that screws to the bottom of the subfloor, that the PEX snaps into. Then, an insulation blanket, similar too the Mylar bubble wrap insulation, but much heaver foil, is installed under the PEX system. These systems are usually fed by a Condensing Boiler, the also feeds the H&V system, (they admit that the radiant floor heating system will not heat the whole room evenly) the domestic hot water tank. These systems are usually installed in high end houses, and I imagine the system is cheaper to operate than a traditional system. Their are also system losses that would eat a small system up in short order.
Your on the way now, "Onward Through the Fogg".
