I am installing a new bathtub that is big enough for two people. with one person leaning against each end of the tub. So I want to have the shower head in the usual position at the end of the tub, but the tub-filling spout in the center of the long side of the tub.

I'm thinking I can I just use one valve/faucet set with a diverter, like the usual setup. I'm thinking the valve/faucet should be closer to the spout. So then, the only difference (than the usual arrangement) is that the pipe from the valve to the shower will be quite a bit longer. The issue is, would the pressure drop to the shower head be such that the flow is too low ? If I understand, shower flow is limited mostly by the shower head, so if I installed a high-flow shower head, maybe I'd be ok.

But if not, if the shower flow would be too low that way, I'd consider installing two completely separate valves/faucets, one for the shower and one for the tub spout. It'd cost a bit more, but it wouldn't be that much trouble, because there are already pipes coming up along the long side of the tub, because the washing machine is on the other side of the wall.

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    Make life simple... Use two different supplies with regular independent valves on each side. If you've gotten to the point in the relationship where sharing a shower head is no longer cute then sharing someone's temperature preference is also around the corner. Soon to follow will be taking showers at the same time altogether so maybe just stick with a standard setup. :) Commented Feb 26, 2015 at 2:07
  • I am only talking about one shower head. But the idea is to have the shower head at the end, as usual, but the tub spout along the long side of the tub. So I'd only be using one at a time. Commented Feb 27, 2015 at 4:57
  • oh I see now. 2 people taking a bath together not showering together. You don't want the spout to be in someone's back. I think 2 valves is the better way to go since you already have the plumbing on the other side of the wall. Easier to run the plumbing that way instead of having to go around the wall and corner. Also easier to repair if something goes wrong in the future. Shower only on one side tub only on long wall. Just my opinion. Commented Feb 27, 2015 at 5:28
  • Yeah, couples shower is in the other bathroom. Two valves is a bit more expensive, but I think it IS better. Commented Feb 27, 2015 at 20:07
  • Have you asked John Redcorn what he would prefer? Commented Feb 27, 2015 at 21:32

2 Answers 2


Hardly any noticeable difference; though a "high flow" showerhead would make any difference WORSE, not better, as well as increasing your water use needlessly.

The water is already traveling through many feet of pipe to get to the bathroom. Whether there's 4 more feet of pipe to the showerhead or 9 more feet of pipe to the showerhead makes very little difference, particularly at the typical 2.5 GPM flow. At a more efficient 1.5 GPM flow, even less.

4 feet of 1/2" plastic pipe @2.5 gpm = 0.625 feet added head. (0.27 PSI)

9 feet of 1/2" plastic pipe @2.5 gpm = 1.406 feet added head. (0.61 PSI)

4 feet of 1/2" plastic pipe @1.5 gpm = 0.243 feet added head. (0.11 PSI)

9 feet of 1/2" plastic pipe @1.5 gpm = 0.547 feet added head. (0.23 PSI)

There's also no particular reason to put the valve set closer to the spout - so you could just put the longer pipe on the spout, and take advantage of the pipes in the shower wall.

  • Thanks, I figured there was a calculator like that somewhere. I want to allow for 3gpm, and I've also got to add the elbows (between a faucet set mounted near the spout and the shower head), 3 of 'em I guess. Still I'm talking maybe 2-3 psi total, not much. Commented Feb 27, 2015 at 5:07
  • I also have to get around the corner (between the long side of the tub and the end) and the way the corner in the stud wall is framed, I can't get an elbow fitting in there, and the minimum bending radius for 1/2" PEX is 5". So that could be a problem, it seems like. Commented Feb 27, 2015 at 5:09
  • You should not need 3 elbows if you are using PEX. As for the corner, you can often improve the path by offsetting it vertically - rather than "going around the corner flat" go around the corner while ALSO going down toward the spout, (or up towards the showerhead) angling down from one side and up from the other, meeting in the middle.
    – Ecnerwal
    Commented Feb 27, 2015 at 5:35
  • Thanks, Lawrence. That makes sense. But I'm starting to think the whole thing, of a person leaning against each end of the tub, is a red herring anyhow. The drain end of the sub is very steep-walled; probably not comfy even with a tub spout in your back. Commented Feb 27, 2015 at 20:05

Super old thread, but should someone come across this like I have, then I would like to point out that offsetting the shower and tub faucets is adding horizontal piping and therefore no additional head height to overcome. A few feet of friction on a horizontal run won't make any difference. Also, someone already made a point that the high flow shower head is a bad idea if there is any concern for limited flow rates for any legitimate reason. Like they said, it will absolutely make everything worse. Consider your low flow rate like having an outdoor faucet to a hose only slightly opened. The end of the hose is like your high flow shower head with a disappointing drizzle coming out. The "low flow" version would be using your thumb to choke the outlet and getting a pressurized jet you can actually effectively rinse something with.

  • Holy really old question, batman. I just ended up doing things the "normal" way. But good points. Commented Dec 3, 2020 at 5:06

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