Which Pipe For Hot/cold To Outbuilding? - Plumbing - DIY Home Improvement | DIYChatroom


Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Plumbing

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Display Modes
Old 04-22-2013, 01:39 PM   #1
Newbie
 
Join Date: Nov 2012
Posts: 20
Rewards Points: 10
Default

which pipe for hot/cold to outbuilding?


I'm planning on adding a bathroom (toilet, sink, shower) to a previously existing outbuilding and have a question on which type of pipe to use.
The water supply, both hot and cold, is about 15' inside the crawl space of the house and then would need to travel and additional ~15'-35' (depending on how I run it) underground to terminate in the new bathroom.

My questions are:

1) Is it even feasible to run hot water in this manner? The location is western Washington state and it doesn't get terribly cold here - maybe only a week or two below freezing per year. I really, really don't want to install a secondary heating source in the new bathroom if I can help it.

2) What types of pipe should I use for each of the two lines?

Advertisement

KingCrabLegs is offline   Reply With Quote
Old 04-22-2013, 06:27 PM   #2
Member
 
Join Date: Nov 2011
Location: Hartfield VA
Posts: 27,798
Rewards Points: 712
Default

which pipe for hot/cold to outbuilding?


I'd use Pex and I would never try and run hot water underground that far.
Guess your not going to do any of this with a permit.

Advertisement

__________________
When posting in forums, letting us know your location will help others give better feedback/advice/solutions to your questions
joecaption is offline   Reply With Quote
Old 04-22-2013, 06:54 PM   #3
Plumber/Contractor
 
TheEplumber's Avatar
 
Join Date: Jul 2010
Location: North Idaho
Posts: 7,281
Rewards Points: 2,638
Default

which pipe for hot/cold to outbuilding?


Pex is what I'd use
You can insulate the hot line- I've piped steam and hydronic lines underground between structures before with lots of insulation
Bury it and the cold at the depth required by local code.
But what are you doing for waste piping?
I believe you're under UPC and if I remember right- 2 buildings cannot share a common sewer line. Not sure about the water piping either. Best to check before proceeding
__________________
When posting in forums, letting us know your location will help others give better feedback/advice/solutions to your questions
TheEplumber is offline   Reply With Quote
Old 04-22-2013, 07:19 PM   #4
Newbie
 
Join Date: Nov 2012
Posts: 20
Rewards Points: 10
Default

which pipe for hot/cold to outbuilding?


Quote:
Originally Posted by TheEplumber View Post
Pex is what I'd use
You can insulate the hot line- I've piped steam and hydronic lines underground between structures before with lots of insulation
Bury it and the cold at the depth required by local code.
But what are you doing for waste piping?
I believe you're under UPC and if I remember right- 2 buildings cannot share a common sewer line. Not sure about the water piping either. Best to check before proceeding
The waste line will be fairly straight-forward, the septic tank is right between the two buildings. Might be a grading issue and I might need a pump.

What material would you use to insulate the Pex? If it's not feasible to do the hot water then I would very reluctantly search for a different option - that's why I asked the question.
KingCrabLegs is offline   Reply With Quote
Old 04-22-2013, 07:56 PM   #5
Member
 
Join Date: Nov 2007
Location: Nashua, NH, USA
Posts: 6,976
Rewards Points: 2,048
Default

which pipe for hot/cold to outbuilding?


Year 'round you will be running the water for a long time waiting for hot water to arrive at the shower in the outbuilding.

You will have to figure out (or just decide) whether a point of use heater in the outbuilding is worth saving all the water you run.
__________________
Forget super sized fries. The Washington Redskins could promote healthy eating with First Lady Obama by choosing a (red skinned) turnip for a mascot.
AllanJ is offline   Reply With Quote
Old 04-22-2013, 08:37 PM   #6
Newbie
 
Join Date: Nov 2012
Posts: 20
Rewards Points: 10
Default

which pipe for hot/cold to outbuilding?


Quote:
Originally Posted by AllanJ
Year 'round you will be running the water for a long time waiting for hot water to arrive at the shower in the outbuilding.

You will have to figure out (or just decide) whether a point of use heater in the outbuilding is worth saving all the water you run.
Yeah, that's kind of the problem. I have no idea how long it will take the hot water to get there so I can't even really make and educated guess on whether the trade off is worth it.

One of the reasons against a point of use heater is that I don't have too much electrical to spare.

Hmmmm....
KingCrabLegs is offline   Reply With Quote
Old 04-22-2013, 10:24 PM   #7
Doing it myself
 
Alan's Avatar
 
Join Date: Apr 2006
Location: Crescent City, CA
Posts: 3,762
Rewards Points: 2,024
Send a message via AIM to Alan Send a message via MSN to Alan
Default

which pipe for hot/cold to outbuilding?


Based on your estimation (15 feet from the crawl space and conservatively another 35 feet underground to the outbuilding) you should have approximately 2 gallons of water in the line you will have to purge before hot starts showing up. This isn't taking into account any distance from that point to the hot water heater.

If your 2 gallon per minute faucet is run wide open then i'd say you have a 60 second wait at least, but probably more than that just based on other factors such as air and ground temperature, and the mixing of the water in the line as it first starts to flow. I'd say you have more like 2 minutes before straight hot water shows up.


Now your shower on the other hand even at a 2.5 gallon per minute rate of flow will never see that much flow, because it's always mixed (shared if you will, between hot and cold). So therefore trying to purge the hot line from the shower valve is going to take a bit longer.


__________________
Journeyman Plumber
Alan is offline   Reply With Quote
Old 04-23-2013, 12:08 AM   #8
Newbie
 
Join Date: Nov 2012
Posts: 20
Rewards Points: 10
Default

which pipe for hot/cold to outbuilding?


Quote:
Originally Posted by Alan
Based on your estimation (15 feet from the crawl space and conservatively another 35 feet underground to the outbuilding) you should have approximately 2 gallons of water in the line you will have to purge before hot starts showing up. This isn't taking into account any distance from that point to the hot water heater.

If your 2 gallon per minute faucet is run wide open then i'd say you have a 60 second wait at least, but probably more than that just based on other factors such as air and ground temperature, and the mixing of the water in the line as it first starts to flow. I'd say you have more like 2 minutes before straight hot water shows up.

Now your shower on the other hand even at a 2.5 gallon per minute rate of flow will never see that much flow, because it's always mixed (shared if you will, between hot and cold). So therefore trying to purge the hot line from the shower valve is going to take a bit longer.

Thanks Alan- that's some great data to work with. I think you guys have convinced me to just run the cold water and add a secondary water heater in the outbuilding.
Thanks a bunch, I really appreciate it.
KingCrabLegs is offline   Reply With Quote
Old 04-23-2013, 07:54 AM   #9
Member
 
Join Date: Nov 2007
Location: Nashua, NH, USA
Posts: 6,976
Rewards Points: 2,048
Default

which pipe for hot/cold to outbuilding?


Oh, by the way, after the slug of cooled off water has been run out of the pipe, the first slug of hot water coming through will have lost much of its heat heating up the pipe. So you could well be running out twice the volume of the pipe before you get hot water.
__________________
Forget super sized fries. The Washington Redskins could promote healthy eating with First Lady Obama by choosing a (red skinned) turnip for a mascot.
AllanJ is offline   Reply With Quote
Old 04-23-2013, 08:35 AM   #10
Member
 
Join Date: Jan 2009
Location: WV
Posts: 3,026
Rewards Points: 2,232
Default

which pipe for hot/cold to outbuilding?


If you have a power issue, why not get a small gas water heater and use propane?
md2lgyk is offline   Reply With Quote
Old 04-23-2013, 11:47 AM   #11
Newbie
 
Join Date: Nov 2012
Posts: 20
Rewards Points: 10
Default

which pipe for hot/cold to outbuilding?


Quote:
Originally Posted by md2lgyk View Post
If you have a power issue, why not get a small gas water heater and use propane?
I haven't considered all of the different water heater options yet. I just wanted the simplest/lowest maintenance installation. I figured that extending the hot water line would be feasible and the best solution.

It might be worth a separate thread to determine an optimal secondary water heater source. The outbuilding is a work-from-home office / shop / workout room. I'd only need the hot water for a max of one shower per day and then the usual hand washing, etc. The shower would have to be *hot* though - warm doesn't cut it for me.

Most of my electrical capacity in the outbuilding is already used up. I'm not sure I could support an electrical water heater, especially during winter when I have two separate electric heaters already running (2 floors). There is a gas line (for a fireplace off the main house) that is accessible between the two structures but tapping into gas is a little beyond my DIY comfort level.

Advertisement

KingCrabLegs is offline   Reply With Quote
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Deep Pipe Clog - Epic Battle Digi Plumbing 37 02-02-2013 12:48 PM
Removing pipe wrap around copper pipe steve3847 Plumbing 1 12-25-2012 03:46 PM
Qs about the 1/2"dia brass pipe we bought smoochas Plumbing 10 02-21-2011 10:23 AM
What’s the best way to remove pipe from T Jaylyn Plumbing 2 02-03-2011 02:05 AM




Top of Page | View New Posts