Upstairs plumbing

JakAHearts · 04-22-2010, 10:20 AM

So Im renovating the upstairs bathroom and had a few general questions. Currently, there is a toilet and a sink. Im going to be adding a tub/shower. Right now, there is the toilet and sink draining into the same main drain. Actually, everything in the house (one other toilet, other shower and kitchen drain) all drain into this main pipe. Anyway, there is also only two water lines running up to the second floor. The cold water line goes to a T and one line runs to the toilet and the other to the sink. They are 1/2 CPVC lines. Do I need to run a new seperate line from the hot water heater and cold lines from the basement for the shower or can I three way from the existing pipes and still get good water pressure for the shower. I dont want the effect where when you turn on the sink or flush the toilet, the water in the shower drops pressure or temperature.

Thanks!

Shane

Grampa Bud · 04-23-2010, 08:08 AM

By your narrative your plumbing layout is very small and you should be able to "Tee" the cold upstairs for the shower and just add a 1/2" cpvc hot line from your lines in the basement. However you didn't say what your family's 'Shock Threshhold' is for hot and cold temperatures. When our shop ran across a customer with questions like yours we automatically upsized the trunk line sizes to the room or sometimes to the fixture wall opening. 1/2" became 3/4 or 1" or for longer runs maybe 1 1/4". The real bottom line is Money, Money, Money.

JakAHearts · 04-23-2010, 09:35 AM

Thanks Grampa Bud. Is there a reason I wouldnt be able to T both the hot and cold water lines? Its not a big deal if not but I was just curious why you said I could T the cold but not the hot. I grew up in a house where when you flushed the toilet you had to step out of the way of the shower water or it would burn your

off. Why should my kids too?

Shane

Alan · 04-23-2010, 10:13 AM

If you get a pressure balanced shower valve you won't have the issue of too hot of water. The only issue you would have is pressure drop.

We would automatically run a 3/4 cold line to a full bath and run 3/4 at least to the toilet. The only problem with upsizing is that you have a larger volume of cold water to purge from the line before your hot gets there.

Grampa Bud · 04-23-2010, 01:23 PM

Alan is right about the larger start up volume and I apologize, my short term memory is obviously going, yes you can "Tee" into both hot and cold in the existing 2nd floor powder room. If you decide to increase your pipe size do look for a pressure balancing shower valve and do increase the pipe size from the basement up to the second floor as the 1/2" won't provide the needed volume to make the balancing spool operate correctly at that distance.

Alan · 04-23-2010, 10:14 PM

Quote:

Originally Posted by Grampa Bud

the 1/2" won't provide the needed volume to make the balancing spool operate correctly at that distance.

I'm confused. I've never heard anything like this before....

SuperPlumberGuy · 04-23-2010, 11:27 PM

Quote:

Originally Posted by Grampa Bud

1/2" won't provide the needed volume to make the balancing spool operate correctly at that distance.

Huh?

04-22-2010, 10:20 AM	#1
JakAHearts Knows everything but that Join Date: Apr 2010 Location: Silver Spring, MD Posts: 165	Upstairs plumbing So Im renovating the upstairs bathroom and had a few general questions. Currently, there is a toilet and a sink. Im going to be adding a tub/shower. Right now, there is the toilet and sink draining into the same main drain. Actually, everything in the house (one other toilet, other shower and kitchen drain) all drain into this main pipe. Anyway, there is also only two water lines running up to the second floor. The cold water line goes to a T and one line runs to the toilet and the other to the sink. They are 1/2 CPVC lines. Do I need to run a new seperate line from the hot water heater and cold lines from the basement for the shower or can I three way from the existing pipes and still get good water pressure for the shower. I dont want the effect where when you turn on the sink or flush the toilet, the water in the shower drops pressure or temperature. Thanks! Shane

04-23-2010, 08:08 AM	#2
Grampa Bud BIGRED Join Date: Apr 2009 Location: Northern Illinois Posts: 480	Upstairs plumbing By your narrative your plumbing layout is very small and you should be able to "Tee" the cold upstairs for the shower and just add a 1/2" cpvc hot line from your lines in the basement. However you didn't say what your family's 'Shock Threshhold' is for hot and cold temperatures. When our shop ran across a customer with questions like yours we automatically upsized the trunk line sizes to the room or sometimes to the fixture wall opening. 1/2" became 3/4 or 1" or for longer runs maybe 1 1/4". The real bottom line is Money, Money, Money.

04-23-2010, 09:35 AM	#3
JakAHearts Knows everything but that Join Date: Apr 2010 Location: Silver Spring, MD Posts: 165	Upstairs plumbing Thanks Grampa Bud. Is there a reason I wouldnt be able to T both the hot and cold water lines? Its not a big deal if not but I was just curious why you said I could T the cold but not the hot. I grew up in a house where when you flushed the toilet you had to step out of the way of the shower water or it would burn your off. Why should my kids too? Shane

04-23-2010, 10:13 AM	#4
Alan Doing it myself Join Date: Apr 2006 Location: Crescent City, CA Posts: 3,454	Upstairs plumbing If you get a pressure balanced shower valve you won't have the issue of too hot of water. The only issue you would have is pressure drop. We would automatically run a 3/4 cold line to a full bath and run 3/4 at least to the toilet. The only problem with upsizing is that you have a larger volume of cold water to purge from the line before your hot gets there. __________________ Journeyman Plumber

04-23-2010, 01:23 PM	#5
Grampa Bud BIGRED Join Date: Apr 2009 Location: Northern Illinois Posts: 480	Upstairs plumbing Alan is right about the larger start up volume and I apologize, my short term memory is obviously going, yes you can "Tee" into both hot and cold in the existing 2nd floor powder room. If you decide to increase your pipe size do look for a pressure balancing shower valve and do increase the pipe size from the basement up to the second floor as the 1/2" won't provide the needed volume to make the balancing spool operate correctly at that distance.

Upstairs plumbing