# outdoor shower plumbing backflow???



## RHulsmeyer (Mar 7, 2012)

Hi all!
Ok, a year later and I have promised The One that this will be the summer where she will shower outdoors in luxury with hot and cold water! I’ve looked at all of the off-the shelf outdoor showers and have decided that I will DIY-it and my design will be rustic and simple made from copper pipe and brass fittings that will be allowed to weather and patina. (See the attached picture as an example.) Instead of a standard shower valve I will use two valves controlling hot and cold flow, that will feed into a common pipe leading to the shower head.
I’ve got all of the easy stuff figured out, including taping into the existing supply lines, running PEX to the outside through an underground conduit, shut-offs and unions for winterizing, waste water drain and tie-ins, etc., etc.. My home is located in New York, Long Island and I am on my own well.
My one big question is do I need some sort of back-flow preventers in the hot and cold lines (see my diagram attached)? I am assuming that there may be some variation in pressure between the hot and cold supply at the combination point and that would cause some flow problems. Is this something that I really need? What product would work? Where in the system should it be installed? Any assistance on this would be helpful. Also any suggestion on valve types would be helpful as well. I want a real common rustic look with a red and blue valve knob for the controls so I don’t want to use ball valves in the shower itself.

Thanks for all of your help!


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## rjniles (Feb 5, 2007)

If this job is permitted, you may be required to use an anti-scald shower valve. Backflow is not required. I would use stop & waste valves in the cellar to drain the lines.


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## joecaption (Nov 30, 2011)

One like this would be legal and you would not have to deal with freeze up and busted pipes.
http://www.woodfordmfg.com/woodford/Wall_Faucet_Pages/Model-22.html


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## TarheelTerp (Jan 6, 2009)

Don't fight the wheel.
Use a standard shower/tub mixer with the tub outlet doing the foot wash.


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## Ghostmaker (Mar 2, 2013)

Code usually requires you use a single handle pressure balanced temperature control shower valve. Just install it then remove the cartridge over winter. No back flow required but your local code may desire a shower drain.


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## TheEplumber (Jul 20, 2010)

You need a valve like Ghostmaker mentioned to meet most codes.
But if you don't want to look at it outside- but it in the basement. Then run a single- mixed line outside.
You can then bullhead a tee for shower and foot spray. The mixer in the basement can be preset for temp. I have done this set up in garages and in kitchen cabinets for exterior hose bibs/showers.
BTW- gate valves are not designed to control volume- but globe and ball valves will


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