If it's cold enough outside for a faucet to freeze, how much do you use it that time of year anyway? Can't you drain it for the season?

Warranty (copper has none) PEX has insulating properties No metal leaching Quiet water movement Can be run to central point like an electric breaker box for isolation When installed as a home run system, like above, no noticible pressure drops at fixtures 1/3 the labor to install with much less probability of a fitting leak Perhaps 30-60% less install price than copper depending on layout I know there is more Usually builders that switched to PEX pocketed the difference of switching. He must be old school or wearing blinders

I was born in 1947 and I can remember when water heaters had no insulation. They were simply an upright galvanized iron tank with a gas burner on the bottom in the same manner as the internal vessel in the modern water heater and water heaters were typically operated at 180degF. (My cousin Robert still has permanent burn scars on his face and shoulder from running into a water heater when horseplaying as a small child.) In those days water heaters had no T&P valve. Instead they had a "Blowout Plug" that would literally blow out of the tank wall when the internal pressure exceeded 150psi. (They worked in the same manner as the freeze plugs installed in automobile engines.) Water heaters had a thermostat on the gas control but there was no thermocouple or flame sensor so if the pilot flame went out and the thermostat called for heat it would blow raw gas into the house. I can remember many occassions when we would come home after being gone for the day and the moment the front door was opened someone hollered "GAS". That meant that the entire house was filled with the smell of Natural Gas, so Dad would open the front and back door and we would all sit in the car across the street for an hour or so till the house vented out praying all the while that the gas in the house would not be ignited by the fire in the old coal furnace, which would then produce an explosion and probably level the house. (These type of accidents were quite common in the early 50's). I can remember when water heater manufacturers were advertising they were on the cutting edge of Space Age Technology with insulated vessels and thermocouple protected pilot burners, of course the insulation blanket was a mere 1/2" of fiberglass with a sheet metal shell over it. Tank walls were still plenty hot but at least you wouldn't receive 3rd degree burns from touching one. Oh, by the way, did I forget to mention that most water heaters had no flue pipes in those days either? They simply vented into the room but that was no problem because in those days fuel was cheap and state of the art construction techniques in those days left so many cracks and crevices that on a cold winters nite you could sit in the living room and watch the drapes moving from the cold drafts around the windows. I find it very interesting to note that during the Viet Nam conflict we were supplying millions and millions of gallons of Jet fuel, Diesel Fuel and gasoline daily to the war effort and yet gasoline was only $.30/gal on the pump and Natural Gas was so cheap that it was commonly thought of as an industrial surplus yet within a year after we pulled out of Viet Nam we had a "Fuel Crisis" where the price of gas jumped to $.75/gal and we had to wait in line to get a meager 8 gal. One would think that when the war ended there would be plenty of fuel for civillian life. Is it possible that the oil companies had lost their Million gallon a day military customer so they now decided to raise the price to keep there profit margins the same? Oh, and don't forget, for every price increase the oil companies got the state and Federal Govt padded in their little tax increases as well, Ah, but thats another topic altogether. Suddenly "Fuel Cost" was a household word and everyone began to tighten up. Houses were being insulated and caulked, speed limits reduced and we began to be concerned with "Standby losses" from water heaters. As the houses were tightened up it became necessary to make water heater flue piping a code mandate and people were encouraged to add "insulation blankets" to their water heaters. The problem with insulation blankets is that if they are improperly installed or if they slipped out of position it restricted combustion air to the burners and we began to see a severe increase in carbon monoxide poisoning in the home. As a result the Codes were again revised mandating that all water heaters MUST HAVE a minimum R-12 insulation. To meet the new standards the water heater manufacturers discontinued the use of fiberglass blanket insulation and began using cast in foams some of which are now providing as much as R-35. The Codes now state that insulation blankets are no longer required and it actually discourages the use of blankets. In fact, many local codes now prohibit the use of insulation blankets on water heaters.

True - but some condensation may occur on the pipe on the warm side of the vapour barrier, but it's very dry here and we have more problems keeping humidity up, so it may not be an issue. I may sprayfoam the section around the pipe for a good seal and will wrap insulation around the outside tap as well, which ought to make a huge difference.