rough in shower plumbing

[jughead]

I am building a walk-in shower and am roughing in the shower plumbing. I roughed in the mixing valve and the diverter is next on the list. I intend to have a separate line to a hand held head, another to a wall head, and another to an overhead waterfall head. My question: since I will be running the overhead rough in lines above the ceiling (up the wall from the diverter, across the ceiling, then down to the waterfall head), is it necessary to allow for a 1/4" / foot rise or drop in the supply line so that the waterfall head supply line can drain or is that unnecessary ? Since most shower heads are vertical from the diverter, drainage is natural due to gravity; however, since I will be running a line vertically, then horizontally, must I allow for supply line drainage (along the horizontal run) or is this overthinking the installation ? The horizontal section is only 4'.
Thanks.

 

[Jamesplumbing06]

What is surrounding the area above your rain head? If an attic or freeze area and worried then I would suggest a simple pipe insulation and try to run high on vertical pipe and fall just slightly toward rain head. But realistically I doubt it will ever freeze. We run water lines in attic here in Tn. Been in 1 attic that got cold enough to freeze water. But they have since insulated and no problems for 9 hard (our hard) winters. So could be overthinking it.

 

[jughead]

I'm not concerned about frozen pipes (I live in Hawaii, and the attic space above the shower probably never gets below 70 degrees in the dead of winter ), my concern was just draining of the supply line once the shower is turned off. I'm guessing that this is a non-issue and that I can run the pipe horizontally with no regard to slope ? Thanks for your response.

 

[Jamesplumbing06]

Yeah the only reason to drain is to avoid freezing. So your good. No worries

 

[jughead]

James: Thanks for the information. As a DIYer, there is always that little insecure voice that questions your every move.
Mahalo!