That was my friend and competitor’s response after he asked me to determine why a recent radiant heating installation was not working satisfactorily because the owners were ticked off. Staple-up installations consist of PEX tubing attached to the underside of the sub-floor with staples or similar fastener. The only direct contact for heat transfer is where the staples are located while the remainder of the PEX droops between fasteners much like wires strung between telephone poles.