Basic Tub to Custom Shower Plumbing Questions

brian3b · 02-18-2009, 05:18 PM

Thanks for reading, i'm a new DIYer and decided to do everything from start to finish in my bathroom.

In regards to the shower, this is what I intend(ed) on doing.

I have 1/2" supply (copper). I was going to use that to one thermostatic valve to run 4 body sprays and a shower head (through a diverter). I wanted to "T" the cold and hot supply and run it to another thermostatic valve wall to control an overhead rain shower and a handshower, again through a diverter.

I would not run all at once, maybe the two shower heads and the 4 body sprays simultaneously. I believe all are 2.5 GPM (so 15 gpm would be max output). My questions:

1. Can I tee the water supply to each thermostatic valve?
2. My PSI says 85 in the basement on the gauge. Will I have enough to run these components?
3. Is a 2" drain sufficient?

Most of this stuff is already been done so I'm hoping for good answers... but please be honest as I haven't installed anything, it's all open so I can change stuff easily... thanks for the input so much!

Oh, if this is too much, suggestions on what to remove or what to do would be AWESOME!

majakdragon · 02-18-2009, 05:44 PM

Only thing I would fret about is supplying more than one head or body spray with 1/2" pipe. Your pressure should not be a problem. 2" is code for showers so I see no problem there. I would read the specs on all your heads and body spray fixtures for manufacturers water supply recommendations. Hope your water heater can supply all the hot water for these uses. Good luck with your project. Sounds nice.

brian3b · 02-18-2009, 05:53 PM

Quote:

Originally Posted by majakdragon

Only thing I would fret about is supplying more than one head or body spray with 1/2" pipe. Your pressure should not be a problem. 2" is code for showers so I see no problem there. I would read the specs on all your heads and body spray fixtures for manufacturers water supply recommendations. Hope your water heater can supply all the hot water for these uses. Good luck with your project. Sounds nice.

I don't understand... if my pressure is not a problem, why would it be a problem to supply more than one shower head? Is it b/c I'm trying to supply to thermostatic valves by using a T in the water supply? What if I T-ed off of my water supply for the sink and ran it for the other thermostatic valve?

Thanks for the quick response!

Also, I have pressure balancing valves, not thermostatic... do I need thermostatic? Thanks!

ironrange · 02-18-2009, 07:19 PM

Quote:

Originally Posted by brian3b

Thanks for reading, i'm a new DIYer and decided to do everything from start to finish in my bathroom.

In regards to the shower, this is what I intend(ed) on doing.

I have 1/2" supply (copper). I was going to use that to one thermostatic valve to run 4 body sprays and a shower head (through a diverter). I wanted to "T" the cold and hot supply and run it to another thermostatic valve wall to control an overhead rain shower and a handshower, again through a diverter.

I would not run all at once, maybe the two shower heads and the 4 body sprays simultaneously. I believe all are 2.5 GPM (so 15 gpm would be max output). My questions:

1. Can I tee the water supply to each thermostatic valve?
2. My PSI says 85 in the basement on the gauge. Will I have enough to run these components?
3. Is a 2" drain sufficient?

Most of this stuff is already been done so I'm hoping for good answers... but please be honest as I haven't installed anything, it's all open so I can change stuff easily... thanks for the input so much!

Oh, if this is too much, suggestions on what to remove or what to do would be AWESOME!

Like the other poster said, 1/2" just won't do it. You won't be happy with the trickle coming out when running all sprays at once. The whole idea of a body spray set up is to have them all running at the same time if you are trying to achieve perfection.
In order to do this right you should run dedicated 3/4" hot and cold to your valves. Most important though is that I hope you bought a valve that has 3/4" inlets, not 1/2". Kohler makes a really nice 3/4" valve, it's very big but will fit inside a 2x4 wall. IF you try doing what you said using 1/2" I doubt you will be happy with it.
I just did the exact same set up for a customer. Custom home with a real nice tile job and it was only a year old. The original plumber installed half inch valves, the spray would come out about a foot and hardly any flow. I ripped it all out and started over. They are now very happy.

brian3b · 02-19-2009, 05:37 AM

Quote:

Originally Posted by ironrange

Like the other poster said, 1/2" just won't do it. You won't be happy with the trickle coming out when running all sprays at once. The whole idea of a body spray set up is to have them all running at the same time if you are trying to achieve perfection.
In order to do this right you should run dedicated 3/4" hot and cold to your valves. Most important though is that I hope you bought a valve that has 3/4" inlets, not 1/2". Kohler makes a really nice 3/4" valve, it's very big but will fit inside a 2x4 wall. IF you try doing what you said using 1/2" I doubt you will be happy with it.
I just did the exact same set up for a customer. Custom home with a real nice tile job and it was only a year old. The original plumber installed half inch valves, the spray would come out about a foot and hardly any flow. I ripped it all out and started over. They are now very happy.

Wouldn't that mean I'd have to run dedicated lines from my water supply? That's two stories below and that's certainly out of the question... Couldn't I test my GPM and then determine how many shower heads I could run at once without sacrificing pressure?

Also, no one has mentioned anything about T-splicing my hot and cold lines to run to two different balancing valves... anyone? Thanks again!

B

JDC · 02-19-2009, 09:06 AM

I have to agree with the above answers. 1/2" waterlines are NOT under any pressure going to supply enough water to your shower. In addition, tee'ing off the existing 1/2" is going to decrease the flow to each valve even more. You really, really, really need 3/4" dedicated waterlines to your shower. 85psi is actually too much pressure on your water distribution system. If you have a pressure reducing valve it needs to be checked. If you dont have one, you need one. You arent looking for pressure but for volume. You need enough volume (flow) to all your fixtures to be happy and 1/2" just isnt going to cut it.

brian3b · 02-19-2009, 09:40 AM

Dedicated 3/4" water lines are DEFINITELY out of the question. It's not even an option. My options are to reduce the number of shower heads to meet what volume and flow rate I currently have.

Correct me if I'm thinking too simply here... If I test my flow rate and get 5 gpm, would it be reasonable to assume that I can run two shower heads (at 2.5 GPM)? That makes way too much sense.

ironrange · 02-19-2009, 09:54 AM

Quote:

Originally Posted by brian3b

Dedicated 3/4" water lines are DEFINITELY out of the question. It's not even an option. My options are to reduce the number of shower heads to meet what volume and flow rate I currently have.

Correct me if I'm thinking too simply here... If I test my flow rate and get 5 gpm, would it be reasonable to assume that I can run two shower heads (at 2.5 GPM)? That makes way too much sense.

Sure, if you're only going to run two heads it will work but that's not what you were asking for. Yes you can splice into the half inch lines but again you can't run them at the same time with the other valve. If you have 5gpm you will only be able to have two heads total running with decent pressure at any one time. So if that's the case, why in the world install what you're trying to do?
You HAVE to run dedicated 3/4" lines. You HAVE to use a 3/4" inlet type shower valve for your system to operate properly. You can't run 3/4" lines to a half inch valve and expect it to work. It MUST be 3/4" dedicated lines to a 3/4" valve and then 3/4" to your diverter.
Pressure isn't the issue here, not sure why you keep bringing that up. It's all about volume.
Yes, it all makes way too much sense. Hope you understand it.

ironrange · 02-19-2009, 09:56 AM

"Dedicated 3/4" water lines are DEFINITELY out of the question. It's not even an option."

Well then forget about the mulitiple body sprays and extra valve, it won't work.

brian3b · 02-19-2009, 10:19 AM

Quote:

Originally Posted by ironrange

So if that's the case, why in the world install what you're trying to do?

Pressure isn't the issue here, not sure why you keep bringing that up. It's all about volume.

Ironman, read my last couple of posts... I'm trying to get information so that I can make an informed decision on what I CAN INSTALL. I realize I cannot do what I initially asked about... not sure why you think I haven't grasped that yet... I did mention that I'm trying to determine my flow rate (which is the volume correct?) so that I can determine how many showerheads I can use.

Ok, pressure isn't the issue. Got it. Volume is. But if I'm getting 5 GPM VOLUME from my 1/2 inch supply, that means I can run 2 showerheads simultaneously

Quote:

Originally Posted by ironrange

Well then forget about the mulitiple body sprays and extra valve, it won't work.

Again, look at my previous few posts. I know it won't now. I originally asked the question and after I understood what people were trying to tell me, I'm now trying to figure out what will work... instead of telling me what won't work (I think this makes 4 times now), why doesn't anyone tell me what will or how I can find out what will work?

ironrange · 02-19-2009, 12:24 PM

"Again, look at my previous few posts. I know it won't now. I originally asked the question and after I understood what people were trying to tell me, I'm now trying to figure out what will work... instead of telling me what won't work (I think this makes 4 times now), why doesn't anyone tell me what will or how I can find out what will work?"

Sure, with what you're working with and being that 3/4" dedicated lines are out of the question for you, you really don't have many options. I guess you could still use the 1/2" valve and the seperate diverter and run one, maybe two heads at a time. Even at two heads you will be maxing out your volume. And sure you could run a seperate valve off your 1/2" lines but you won't be able to use both valves at the same time, only one so what would be the point of doing that?
Sounds like you need to hire a professional plumber to run those 3/4" lines for you, good luck.

brian3b · 02-19-2009, 05:16 PM

Quote:

Originally Posted by ironrange

Sure, with what you're working with and being that 3/4" dedicated lines are out of the question for you, you really don't have many options. I guess you could still use the 1/2" valve and the seperate diverter and run one, maybe two heads at a time. Even at two heads you will be maxing out your volume. And sure you could run a seperate valve off your 1/2" lines but you won't be able to use both valves at the same time, only one so what would be the point of doing that?
Sounds like you need to hire a professional plumber to run those 3/4" lines for you, good luck.

So I conducted the test... it took 25 seconds to fill a 5 gallon bucket. I did the test 3 times with the same results. Based on my calcs that means my 1/2" pipes are pushing 12 gallons per minute... Which is enough volume to supply almost 5 shower heads, is that right? Unless I'm missing something with the whole volume vs. pressure thing, common sense says that I could run 4 heads simultaneously with no problem and 5 with very little negative effect on water pressure coming into the shower. Am I wrong, someone please confirm or tell me I'm an idiot!

ironrange · 02-19-2009, 07:00 PM

Quote:

Originally Posted by brian3b

So I conducted the test... it took 25 seconds to fill a 5 gallon bucket. I did the test 3 times with the same results. Based on my calcs that means my 1/2" pipes are pushing 12 gallons per minute... Which is enough volume to supply almost 5 shower heads, is that right? Unless I'm missing something with the whole volume vs. pressure thing, common sense says that I could run 4 heads simultaneously with no problem and 5 with very little negative effect on water pressure coming into the shower. Am I wrong, someone please confirm or tell me I'm an idiot!

Where did you conduct this test? Did you take the actual flow from an existing shower valve because most 1/2" shower valves will put out between 3 and 5 gpm. It doesn't matter what your 1/2" pipes are puting it out, it still has to be run through a shower valve!!!!!!
The high end Kohler with 3/4" inlets puts out 12 GPM max. There is NO WAY you will get even close to that with your 1/2" valve. See the link: http://www.us.kohler.com/tech/produc...owerhiflow.jsp
I usually don't get this involved with trying to explain something over and over again to a DIY'er when they can't comprehend, I believe you're over your head and time to call in a professional plumber, good luck. I'm done.

brian3b · 02-19-2009, 07:22 PM

Quote:

Originally Posted by ironrange

Where did you conduct this test? Did you take the actual flow from an existing shower valve because most 1/2" shower valves will put out between 3 and 5 gpm. It doesn't matter what your 1/2" pipes are puting it out, it still has to be run through a shower valve!!!!!!
The high end Kohler with 3/4" inlets puts out 12 GPM max. There is NO WAY you will get even close to that with your 1/2" valve. See the link: http://www.us.kohler.com/tech/produc...owerhiflow.jsp
I usually don't get this involved with trying to explain something over and over again to a DIY'er when they can't comprehend, I believe you're over your head and time to call in a professional plumber, good luck. I'm done.

I'm sorry for not comprehending man. Thanks a lot for your help, believe it or not you did help me quite a bit and I really appreciate it.

How do you explain this flow-rate chart though: http://www.faucetdirect.com/mediabas...D560158_ss.pdf

02-18-2009, 05:18 PM	#1
brian3b Newbie Join Date: Feb 2009 Posts: 13	Basic Tub to Custom Shower Plumbing Questions Thanks for reading, i'm a new DIYer and decided to do everything from start to finish in my bathroom. In regards to the shower, this is what I intend(ed) on doing. I have 1/2" supply (copper). I was going to use that to one thermostatic valve to run 4 body sprays and a shower head (through a diverter). I wanted to "T" the cold and hot supply and run it to another thermostatic valve wall to control an overhead rain shower and a handshower, again through a diverter. I would not run all at once, maybe the two shower heads and the 4 body sprays simultaneously. I believe all are 2.5 GPM (so 15 gpm would be max output). My questions: 1. Can I tee the water supply to each thermostatic valve? 2. My PSI says 85 in the basement on the gauge. Will I have enough to run these components? 3. Is a 2" drain sufficient? Most of this stuff is already been done so I'm hoping for good answers... but please be honest as I haven't installed anything, it's all open so I can change stuff easily... thanks for the input so much! Oh, if this is too much, suggestions on what to remove or what to do would be AWESOME! Last edited by brian3b; 02-18-2009 at 05:36 PM.

02-18-2009, 05:44 PM	#2
majakdragon Member Join Date: Sep 2006 Posts: 1,670	Basic Tub to Custom Shower Plumbing Questions Only thing I would fret about is supplying more than one head or body spray with 1/2" pipe. Your pressure should not be a problem. 2" is code for showers so I see no problem there. I would read the specs on all your heads and body spray fixtures for manufacturers water supply recommendations. Hope your water heater can supply all the hot water for these uses. Good luck with your project. Sounds nice. __________________ If you have never made a mistake, you haven't done much.

02-19-2009, 09:06 AM	#6
JDC Plumbing Contractor Join Date: Mar 2008 Location: Cincinnati, OH Posts: 379	Basic Tub to Custom Shower Plumbing Questions I have to agree with the above answers. 1/2" waterlines are NOT under any pressure going to supply enough water to your shower. In addition, tee'ing off the existing 1/2" is going to decrease the flow to each valve even more. You really, really, really need 3/4" dedicated waterlines to your shower. 85psi is actually too much pressure on your water distribution system. If you have a pressure reducing valve it needs to be checked. If you dont have one, you need one. You arent looking for pressure but for volume. You need enough volume (flow) to all your fixtures to be happy and 1/2" just isnt going to cut it.

02-19-2009, 09:40 AM	#7
brian3b Newbie Join Date: Feb 2009 Posts: 13	Basic Tub to Custom Shower Plumbing Questions Dedicated 3/4" water lines are DEFINITELY out of the question. It's not even an option. My options are to reduce the number of shower heads to meet what volume and flow rate I currently have. Correct me if I'm thinking too simply here... If I test my flow rate and get 5 gpm, would it be reasonable to assume that I can run two shower heads (at 2.5 GPM)? That makes way too much sense.

02-19-2009, 09:56 AM	#9
ironrange MasterPlumber Join Date: Feb 2009 Posts: 33	Basic Tub to Custom Shower Plumbing Questions "Dedicated 3/4" water lines are DEFINITELY out of the question. It's not even an option." Well then forget about the mulitiple body sprays and extra valve, it won't work.

Basic Tub to Custom Shower Plumbing Questions