[DieselDoctor]

There is a special tubing for in-floor heat and is joined and manifolded in the same manner as PEX but the tubing is of a material that will hold up to life long exposure to concrete. The biggest issue is tying the tubing onto the stanchions to position the tube in the slab. You create your forms, lay in the insulation, lay your bar or mesh reinforcements, then carefully lay out your heat runs (zones) and twist tie the tube onto little plastic stanchions (risers). The trick is to not cut or chafe the tube while rolling it out. When we poured 35 yards for the floor in a museum, we rented a couple of rechargeable tie guns that twisted the preformed loop of wire. Some guys swear by zip ties, but the professionals all use the wire as it is faster. Make sure to sketch an accurate drawing of the exact location of each tube. Pictures help. If the slab must be cut for expansion joints, you need to know where the tubes are. Also if you ever drill and bolt to the floor for a lift or some other machine the same thing goes!
You will love the in-floor heat. No noise, no dust or cold drafts, and the floor dries very quickly when water is spilled or the floor is washed. If you work under vehicles as I do, you will be working in shirt sleeves!