View Full Version : shower remodel adding body sprayer flow issues...

chris fox
05-09-2007, 10:18 PM
Hello everyone this is my first post. This site was recommended by John Bridge site.
I am a DIYer and in the middle of a bath remodel. While tearing my shower apart for new drywall and for kerdi wrap, I thought to add a body sprayer or 2 in addition to a rain like shower head that will replace a typical shower head.
The house was built in 1995 and assume, especally here in Phoenix, that a water restrictor is in the valve. This was also realized in the fact that the nearby tub has tons of flow and the shower is less than powerful.
Attached are pics of the shower wall open. I was surprised to see the hot water line loaded with elbows etc which may be effecting water flow? but some thought(on John bridge) it woulnt make a difference if I added a flex copper line in place of the complex line, I dont know for sure?

So my intent is to add a couple of body shower sprayers near the shoulder on the same wall as the valve. My concern is adding lines for body sprayers and find I have no pressure.
As a flow test I added a garden hose to the shower riser pipe(elbow) and found I was filling(hot line only) 3 gallons in 45 secs so pretty close to 2.5 gallons a minute.
1. are there valves specially made for body sprayers and a overhead?
2. recommendations on install diagrams etc. most likely wont be using a complete kit but purchasing a couple of sprayer heads seperatly.

Thanks is advance, I hope to learn alot from this site...

chris fox
05-09-2007, 11:10 PM
here they are...

05-10-2007, 05:39 AM
The flow rate through that valve is immaterial because it is not pressure balanced which the new shower would, and should, require. The tees and elbows you are referring to is the manifold that feeds the rest of the house. It has nothing to do with the flow to your shower valve. To operate two different devices, you need a proper shower valve, and a diverter valve, (or two volume control valves), so you can select which one you wish to operate, (or both at the same time). Your new valve will have a large port for use with a tub spout and a smaller one for the shower. For maximum flow, connect your shower to the "spout" connection and either plug or also connect the shower port to the piping. Sometimes you can invert the valve to make the connection, and other valves require that you route the piping to the bottom of the valve.

chris fox
05-10-2007, 10:29 AM
Thanks HJ.
I think I am a little lost on your reply. The tees and elbows are up above the 3 lines(hot and cold) that come out of the slab. I understand this was done because connections cant be made in under slab.
Well I know I have approx. 2.5 gpm. But have done some research of valves having 5gpm for multiple spounts, which I am assuming your referring to for new valve.
So if the new valve will have connection for tub(which is not water restricted) this should be used for shower and sprayers(piped off after connection) vs using shower port.
Do you recommend a plumbing house here in Phoenix(scottsdale airpark area). I notice the Borg doesnt have a selection of valves and divertors for multiple heads.


05-10-2007, 12:36 PM
Each head can draw up to 2.5gpm. So, add up how many you want, and then look at both your water pressure and the flow of the valve you want. Many are available in both 1/2" and 3/4" supplies. If you don't have a bunch more than 2.5gpm, don't consder more than one head at a time, or you will be dissapointed. A typical valve on 1/2" supply can flow around 6gpm. A 3/4" valve can flow upwards of twice that. Many company's valves are somewhat common, and then you pick the trim part you see for the style. They generally come in either pressure balanced or thermostaticly controlled. You are required to use one or the other by code on a new installation or major remodel. I prefer the thermostatically controlled valve, since until you actually run out of hot, it maintains the set temperature. If you are going to go with multiple shower heads, that will come sooner than you want, and all the while, the temperature would be falling as you empty the tank unless you go with a thermostatically controlled one.

chris fox
05-10-2007, 01:08 PM
Thanks Jim for the input.
I plan to add 2 body sprayers on the smae wall as the valve and riser pipe- simple! I dont know what valve I have but assumiing its 2.5 gpm since the house is 12 years old. The copper lines are 1/2 so will stick with this size. Thermocontrolled was what i was recommended at the Borg, if I did go this route then I would want a flow control too correct? With only 2 body sprayers and not a whole spa like system I will want the sprayers and rain head to work simultaneously.
As far as the 2.5 gallons i tested with a bucket this was with the existing valve still on(see pic). So with a 7.5gpm valve I should be able to get all 3 to work at the same time.
Being a plumber newbie what the best way to test pressure befire the valve, tap in a pressure guage at the shower before the existing valve? I assume i can get the same test off a outside spicket and use a screw on guage and convert gpm which would be going in at the shower?
Were looking at using a Grohe brand rainhead and sprayers.

thanks again,


05-10-2007, 02:45 PM
Unless the outside spigots are plumbed before a PRV, the pressure should be the same there as at the shower (within a small difference if it is up a couple stories).

The actual flow you get will be determined by the valve, the size of the pipe, how many restrictions (angles, etc. ) there are in the system, and the incoming pressure. How many other valves are open at the same time will affect it, too.

chris fox
05-10-2007, 03:23 PM
Ok. I will pickup up a guage and screw on to the spikot thats closets to the street. Which I know i have high pressure. PRV pressure relief valve??
If you looked at my pics in my second post, the hot line to the shower vlave has 6 elbows which were used to snake around a vent pipe. uy at JB thinks this is where I m losing flow at hot side. But still the 3 gallon test at 45 secs. proves a 2.5 gpm flow right at the riser elbow to the shower neck.
So most likel ythe shower head.

So with that said, a new valve(s) 7.5gpm and/or divertors are needed for my 3 sprayer shower(whihc includes the shower rain head)

thanks chris

05-10-2007, 05:06 PM
By law in the USA, a showerhead is limited to 2.5gpm. Now, whether a rain head adheres to that, I don't know. So, legally anyways, with three heads, you could require 7.5gpm. That's a lot for a 1/2" supply, and if all were going at the same time, will deplete a WH pretty quickly, so be aware of that.

chris fox
05-10-2007, 10:07 PM
With more research into valves, trim covers and multiheads and rain showers it kills my budget. So sticking with rainhead with a 12" neck, etc.
So this simplifys things, however with the Kohler or Grohe style that I want I will need a rough in valve(not included) so I think but assuming so and cant use my existing valve. I would plan to use a thermostatically controlled valve.

What about flipping this new valve to use tub side of the valve? my guess specific valves for specific trim kits wont work this way?