Tub / Shower Design Question

[ElLlamero]

I'm in the middle of a shower-to-bathtub conversion for my master bath. I've picked out a few Hansgrohe fixtures, and even run them by Hansgrohe support to confirm they'll work together. However, when I was getting quotes from suppliers, I had one supplier say there was a major issue with my design, and that I should consult a plumber. Given this forum has been a great source of advice in the past, I thought I'd start here.

The concern was regarding my use of three water sources with two diverters. The person was concerned that I could experience a backflow issue due to negative water pressure. Overall I don't understand the concern, but perhaps someone here will have some experience with this sort of two-diverter design.

Here's the design.

Here's the parts list, all Hansgrohe:

Model #		Component - Description
 1850181	Valve Rough -	iBox Universal Plus Rough with Service Stops, ¾"
 4231000	Shower Valve - 	S Thermostatic Trim with Volume Control and Diverter
15984181	Diverter Valve -	Rough, Trio 2-Way Diverter, ¾"
 4232000	Diverter Trim -	S Trio/Quattro Diverter Trim
14413001	Tub Spout - 	S Tub Spout
27458003	Wall Outlet -	Wall Outlet with Check Valves
 4266000	Slide Bar Hand Shower -	Unica S Wallbar Set, 24"
27479000	Shower Pipe -	Extension Pipe for Ceiling Mount
27381001	Overhead Shower - 	Raindance E 360 AIR 1-Jet Showerhead

I'd also appreciate any other comments or suggestions. In particular, is it better to run the overhead shower with copper or PEX? It's through an attic, so it seems PEX would be easier and more freeze-tolerant. The rest of the system is copper.

Thanks!
Jason

 

[Terry]

That looks good to me.

The 4231000 has temperature control, and diverts to the tub spout or to the showers.

The 15984181 diverter choses between the two showers if the lower control sends water that way. I can't tell if you are allowed to have both showers on at the same time. Some diverters don't allow both on, and some do.
If it were me, I would want the option of having either one shower head, or both.
PEX over head may be a good idea. You can't run PEX to a tub spout, but for a shower head it's fine.

 

[Sponsor]

 

[JohnfrWhipple]

Jason make sure you test these fixtures so they work they way you want after the hook up. Is it your plan to always have the tub filler running?

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If not then you might have the drawing wrong. I'm guessing the thermostatic can have one on or two on.

Be careful with the pipes in the attic. Use a proper insulation approach. We have discusses this a lot here.

Many times these rough ins have multiple outlets and you need to think which way works best. Sometimes the trims have their own diverters. I would look for a three way divisor myself and send one leg to each unit or any two. Or add in another diverter before the tub filler if the thermostatic control does not doe this all ready.

I just ripped out my buddies tiled wall because his buddy $%^&*T'd this up.

 

[ElLlamero]

Thanks for the great feedback.

Terry - The diverter comes in two flavors, shutoff and no shutoff. Both allow simultaneous operation, but I opted for the no-shutoff version since I already have volume control in the thermostat.

John - The Thermostat + Volume control is no flow at 12 o'clock, outlet one at 9, outlet two at 3, and both outlets at 6. It also has a removable diverter cartridge stop ring that prevents simultaneous operation if it's not desired, as in my case.

I'll definitely have blown insulation over the ceiling pipe, but the expansion ability of the PEX is an added benefit.

Thanks again!

 

[Vegas_sparky]

The blown in insulation may not be enough to protect the overhead piping. John, and Terry have had some great discussions, and provided detail drawings for bulletproof protection. Of course it all depends on where you live, and what kind of temperatures the piping may be exposed to.

 

[Jadnashua]

IF your pipe runs right next to the ceiling, and there are no drafts or air leaks, it should not be much cooler than the room below. Otherwise, all bets are off. But, if you can slope things a little bit (the diverter may mess up draining), often, that run has no water in it. I think yours will, so you'll get a spurt of either hot or cold water when you activate it based on whether it is summer or winter before the water that is there gets purged out. There are good reasons to sometimes using a diverter tub spout, since the lines can drain between uses. I have a volume/diverter control similar to yours, and the line to the showerhead does not drain - a wakeup when you forget when you first turn it on if you don't get out of the way!

 

[ElLlamero]

Being in Austin, TX, we only get a day or two of hard freeze each year. The bathroom will be conditioned space, so I think running near the ceiling will cover me. I have seen the insulation boxes posted in other threads, very good advice.

I appreciate the advice on using a diverter spout to allow draining the lines, I'll give it some thought.