Can PEX be used in Thermal Mass radiant heating?
Yes. Since PEX comes in rolls of 1000′ and some brands have a bend radius of 5″ you are able to lay down the tubing in a continuous length without any fittings in the slab. Chemicals in concrete have no effect on PEX but you should put some kind of sleeve on it when you are going into or coming out of the slab.