PEX install on older home using too small diameter pipe?

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by pexhouse, Feb 4, 2014.

  1. hj

    hj Moderator & Master Plumber Staff Member

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    quote; He didn't know that and went and got 1/2" PEX, copper and galvanized off his truck and sure enough it is much smaller. He said he'd do 3/4" if I wanted it but that would be extra $$$$. He said going to 3/4" wouldn't help the pressure or flow at all.

    It will not help the STATIC pressure, but will help the dynamic pressure AND flow. Using geometry, a 3/4" PEX pipe has TWICE the volume of a 1/2" one, and a 1" pipe would have FOUR times the volume. If he didn't know the difference between 1/2" galvanized, copper, and PEX, then that is why he doesn't know how changing the pipes would be an improvement. Here, if you contacted the Registrar of Contractors, they would MAKE him install the correct size at NO extra cost, once the smaller piping was installed. I know our code, and I am sure it is the same where you are, specifies 3/4" piping TO THE WATER HEAtER.
     
    Last edited: Feb 7, 2014
  2. houptee

    houptee Member

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    Why did your friend the inspector have to come take a look?
    It should have been inspected once already and passed or failed if the plumber pulled a permit.
    In NJ it even says on the back of the permit you hang in the window of your house: Final payment to contractors should not be made until a Certificate of Occupancy is issued, pursuant to NJ State Law 13:45A-16.2
     
  3. hj

    hj Moderator & Master Plumber Staff Member

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    quote; He'll have a coronary if he has to dig up the yard at his cost.

    That's what he gets for giving you a lowball figure. Your inspector must have been one of those inept contractors who went broke and decided to go to work for the city.
     
  4. craigpump

    craigpump In the Trades

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    Hard to believe a licensed plumber doesn't know that there is a difference in ID's between galvanized, copper and Pex.
     
  5. pexhouse

    pexhouse New Member

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    Oklahoma
    It's all OK when just one thing is running. I say OK but in reality I've never seen everything in this house run with a large, clean pipe so not sure if one thing running would work even better with a larger pipe. Currently from what I see where it starts to have problems is when more than one thing is open and turned on. A good demonstration of this is turning on the shower and washing machine at the same time while I turn on and off the hot water on the main bathroom sink. Doing this I can make the water dance like it's the water display in front of the Bellagio hotel in Vegas.

    After Terry's Friday post above I was up till 1am Saturday and spent much of yesterday printing pages off and reading the IPC. I am going to post my figures and a graph I have drawn up of my house to hopefully give an indication if I understand and have done this correctly. My community uses IPC 2009 so that is what this is based from unless noted.

    First from TABLE E103.3(2) here: http://publicecodes.cyberregs.com/icod/ipc/2009/icod_ipc_2009_appe_sec003.htm

    [​IMG]

    TOTAL WFSU
    ---------------------------
    Bathroom Group - 3.6
    Water closet - 2.2
    Lavatory - 0.7
    Kitchen Sink - 1.4
    Dishwasher - 1.4
    Washing Machine- 1.4
    Hose Bibb - 2.5 (Figure from IRC 2012 TABLE P2903.6 http://publicecodes.cyberregs.com/icod/irc/2012/icod_irc_2012_29_par034.htm)
    Hose Bibb - 2.5 (Figure from IRC 2012 TABLE P2903.6 http://publicecodes.cyberregs.com/icod/irc/2012/icod_irc_2012_29_par034.htm)
    Total: 15.7

    HOT WFSU
    ---------------------------
    Bathroom Group - 1.5
    Lavatory - 0.5
    Kitchen Sink - 1.0
    Dishwasher - 1.4
    Washing Machine- 1.0
    Total: 5.4

    Following calculations based from here: http://publicecodes.cyberregs.com/icod/ipc/2009/icod_ipc_2009_appe_sec004.htm

    MAXIMUM DEVELOPED LENGTH
    -------------------------------------
    Meter to front of house - 32'
    Front of house to water heater - 49'
    Water heater to furthest hot faucet - 32'
    Total: 113'
    multiplied by 1.2 for fittings loss = 136'

    [​IMG]

    TABLE E201.1
    Based on the 150' "Maximum Developmental Length" column and WFSU of 15.7, 1/2" pipe is up to 1.5 (too small), 3/4" is up to 6.5 (too small), but 1" pipe is up to 25 so the main distribution pipe in my house, according to code, would be 1". Would that be a 1" line all the way to the water heater?

    Based on the same "Maximum Developmental Length" of 150' and a hot WFSU of 5.4, 1/2" pipe is up to 1.5 (too small), 3/4" is up to 6.5 so my hot water main line from the water heater would require 3/4" to meet code. If I did do this correctly I do have one question. Once the main hot passes the dishwasher, kitchen sink and washing machine, it just goes to the 2 bathrooms that have a WFSU of 2. Does that mean the 3/4" changes to 1/2" on it's way to the bathroom or does it stay 3/4" for the entirety of its run? One thing I am worried about if 3/4" is taken all the way to the bathrooms is that the hot water will take longer to get there. That is one thing that is MUCH improved since the new lines is the hot water getting to the bathrooms much quicker. I'm assuming that's because it's a small 1/2' PEX pipe that is flushed of cold water quickly when a hot tap is opened.

    Also of note is the plumber used a mini-branch and put the cold shower and main bath toilet on the same run. Since a toilet is 2.2 and shower is 1 that would equal 3.2 and would be a code violation (maximum of 1.5 on 1/2" @ MDL of 150') and that branch should be changed to 3/4".

    Here's a drawing of the plumbing layout of my house:

    [​IMG]

    http://imageshack.com/a/img835/8051/uqiv.jpg


    Thanks for the help everyone!
     
    Last edited by a moderator: Feb 10, 2014
  6. Terry

    Terry Administrator Staff Member

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    For starters, let me say how proud I am of you. You have taken this information and run with it. :)

    It would be 1" from the meter, and for most of the cold in the home. Since the water heater is only concerned with the hot, 3/4" is enough for that.
    I'm still a bit tired from skiing today, so I would want more time to go over the calculations. You are very close to a perfect understanding of this though. When you and I get this totally figured out, it would be interesting to contact your local newspaper with this information. I think it's very important for your community that people realize that the building department is not sticking up for the rights of the homeowners there. This is big!
     
  7. pexhouse

    pexhouse New Member

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    Oklahoma
    Thanks :)

    One thing I am not sure on is my understanding of your saying the line from the meter needing to be 1" and not 3/4". I was reading the third row to mean 3/4" service pipe from the meter to the front of the house and 1" distribution pipe under the house for the main trunk.

    It would seem logical to make it 1" but I'm not seeing how that is specifically stated in the code.
     
  8. Terry

    Terry Administrator Staff Member

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    Let me play with that tonight.
    I have some plumbing I need to get to. Throwing in some HansGrohe stuff.
     
  9. pexhouse

    pexhouse New Member

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    Oklahoma
    I'm mainly clear (imho) on everything except what the pipe under the front lawn (water meter to the front of the house) should be (in reference to the 1" you stated above). I think this is because I am confused by the terms due to me not being a plumber.

    To put it simply I thought on these charts http://publicecodes.cyberregs.com/icod/ipc/2009/icod_ipc_2009_appe_sec004.htm the "METER AND SERVICE PIPE" meant from the water meter to the front of the house and "DISTRIBUTION PIPE" meant the main pipe under the home (on it's way to the water heater). That was how I took it from the IPC2009 definitions page. However on your page here https://terrylove.com/watersize.htm it's implying that the first column is something else while the second column is basically everything from the water meter to the water heater. Thus on the IPC2009 page linked above it would mean all the main pipes would be 1" (like you previously stated). I admit that seems to make more sense but I still want to make sure I 100% understand this when I go to the inspector.

    That would make more sense with some of what I was reading. For instance on the IPC page linked above point .5 last sentence reads, "In no case does the size of any branch or main need to be larger that the size of the main distribution pipe to the building established in Step 4." (bolding mine) That makes it sound like it's under the lawn, or includes what's under the lawn, as well as the entire sentence to me implies that whats under the house can't be larger than what is under the lawn from the meter.

    If that's true then the size (currently 3/4") under the lawn needs to be 1".

    ug...hours of looking over the codes and trying to figure it all out makes me look like this:

    Beaker.jpg
     
  10. Terry

    Terry Administrator Staff Member

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    [​IMG]
    The Medium pressure chart
    3/4" Water Meter
    1" line from meter to home.
    1" cold main line
    3/4" cold to water heater
    3/4" hot from water heater until it reaches the bathroom groups.

    [​IMG]

    [​IMG]
     
  11. pexhouse

    pexhouse New Member

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    Oklahoma
    I just called up and talked with the inspector and he said that the city hasn't adopted the Appendix (all what I'm showing him is out of Appendix E) and it has to be out of the 'code' (meaning non-appendix) part of the IPC 2009.

    Can anyone tell me what is going on because I'm lost?!?!
     
  12. Terry

    Terry Administrator Staff Member

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    What is the name of your local newspaper?
    I think the building department where you live are the ones that are "lost".
     
  13. pexhouse

    pexhouse New Member

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    Oklahoma
    ok he just called me back and said that the International Residential Code 2009 is what is used for the residential code, whereas the IPC is more for the commercial. I didn't know he was using the IRC and he didn't know I was using the IPC. I do see in the IRC it says a minimum 3/8" can be used on an under 60-foot run so that's where he was getting that from before.

    He said what he and the plumber agreed on after discussion is they're going to extend the 3/4" all the way to the hot water heater and that is it. I think that is the best deal that I'm going to get out of this. Pushing any more than that and I think the doomsday clock for WWIII will start ticking down.

    I'm looking and the charts in the back look like the same ones that are in the IPC http://publicecodes.cyberregs.com/icod/irc/2009/icod_irc_2009_appp_sec004.htm

    ...so I'm not sure where it says more than 3 wfsu, in the most optimistic case, can be put on a 1/2" line. However, he did say he had some engineering guide or manual (?) he said he was looking at so that's something I can't look at or comment on. He said according to that book 7 wfsu can be put on a 1/2" (I think 7 was the number he said) so I don't know.
     
    Last edited: Feb 11, 2014
  14. Reach4

    Reach4 Well-Known Member

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    IL
    Since there is 1/2 already in place, I wonder if this would both minimize his work and give better performance than just replacing the long run with 3/4. Just an idea, that may have no merit. New 3/4 in orange with a Tee at each end.

    huge4.jpg

    On the bright side, with 1/2 from the water heater, the bathroom sinks will not have to wait as long for hot water.

    Any thought about adding a water softener?

     
    Last edited by a moderator: Feb 11, 2014
  15. wjcandee

    wjcandee Wise One

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    New York, NY
    Of course they are.

    Your inspector is a moron and your plumber is a hack. And the inspector has no balls.

    There has to be somebody above the inspector that you can talk to. You might share your observation that he seems to have minimal familiarity with the plumbing code, and point him to Terry and my suggestion that the local newspaper might find all this to be very interesting. The bottom line is that you can and should have a house where flushing the toilet doesn't make the shower into a dribble. In our (old, old) house, with nice big copper pipes. We can run the dishwasher, the washing machine, flush the toilet, and have someone open the faucet to brush their teeth without me having my shower go from a nice jet to a dribble each time some other user accesses water. The cost for that nirvana, using pex, wouldn't/shouldn't have been all that different, since it involves THE EXACT SAME AMOUNT OF LABOR.

    That your hack plumber didn't know that pipes made of different materials have different internal diameters says it all, as far as I am concerned.

    EDIT: Maybe I should put a little more flesh on the bones as to why your inspector is a "moron". Now I don't practice law in your jurisdiction, and your jurisdiction may have some weird rule that I don't know about (but I doubt it), but When you adopt a code you adopt the appendix, unless expressly disclaimed. Why? Because the appendix has the details in it and is referenced by the code. That's why it's there. To say it "hasn't been adopted" is just stupid, or, worse, a bs excuse by someone who is rapidly realizing they have no clue what they are doing. Second, how is it that this guy doesn't know off the top of his head what the dimensional piping requirements are for residential plumbing? Even a non-plumber like me can look at that grouping of fixures and know as a broad sweeping generalization that the "low" and "medium" fixture unit limits aren't going to apply. I'm pretty sure that Terry, or Bert Polk the plumbing inspector who is oft-referenced here, can do it quick and dirty in their head and come within a fixture unit or two. And then know what that means in terms of required pipe size. That your inspector DOESN'T EVEN KNOW WHICH TABLE TO LOOK AT is just plain frightening. Third, that he tries to tell you that the IRC is going to give you a meaningfully-different result than the IPC is also stupid. Why? Because it just makes sense that a fixture unit is a fixture unit is a fixture unit. No suprise that the table in the IRC looks like the table in the IPC. DUH. Your inspector is making excuses for a bad job by the plumber. The inspector is not acting in your best interest. Your City Attorney can certainly be called upon to tell him which code applies (and which appendices). It's funny to me that here at our place in the country, the plumbing inspector is a notorious hardass. Fair, but a hardass. Meticulous. He wants it done right, and if it isn't, it's coming out. This means that plumbers here know that they need to do it right, or they are going to have to do it over. This may be why everything is so darn expensive (boo). But at least the guy is trying to make sure that the consumer is protected from shoddy work.

    In fact, let me put a finer point on it: It is the inspector's job to know when it isn't right. That he doesn't know, and doesn't know how to determine if it's right, is a real problem.
     
    Last edited: Feb 11, 2014
  16. Terry

    Terry Administrator Staff Member

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    wjcandee,
    I was waiting for you to weigh in.
    The entire interchange between the homeowner and the inspector has blown me away. I hope the inspector is a volunteer and not being paid for his lack of knowledge and schooling.
    The fact that he doesn't even care to learn his craft or job, is amazing. People pay hundreds of thousands of dollars for homes, and banks make loans on those homes, believing that they were built to "American" building codes.
    This isn't the Bush of Africa where the women carry water for miles daily. Here in the U.S., it's expected that you have these things called faucets, and water comes out of them. If this is all too techical for the plumbing inspector, perhaps he needs to step aside and let someone with some education take over. Everything that has been discussed about this job is something a six month apprentice knows.

    http://www.tests.com/Oklahoma-Plumbing-License-Exam

    http://www.contractors-license.org/ok/Oklahoma.html#ok3

    If I'm doing this job on the West Coast, it looks more like this.

    [​IMG]
     
    Last edited: Feb 11, 2014
  17. Terry

    Terry Administrator Staff Member

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    That would be for one plumbing fixture. Not an entire home. And that's the minimum size for "one" fixture.
    Why do I get the idea that this inspector lives in the woods?

    Here is a video for UPC plumbing.
    Same sizing applies though.



    Or this link too.

    http://www.finehomebuilding.com/item/4829/three-designs-for-pex-plumbing-systems
     
    Last edited: Jul 19, 2014
  18. wjcandee

    wjcandee Wise One

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    That section he's referring to expressly relates to a line FROM A MANIFOLD to an INDIVIDUAL FIXTURE, as Terry notes above. It's the subheading "minimum size" under the heading "Gridded and Parallel Water Distribution System Manifolds", which says "Hot water and cold water manifolds installed with gridded or parallel-connected individual distribution lines to each fixture or fixture fittings shall be designed in accordance with Sections [1-6, including the section (2) I just cited]".

    I find this stuff easy to read because I'm a lawyer, but anybody tasked with interpreting the code should at least have an understanding of what requirements relate to what circumstances.

    [​IMG]
     
    Last edited by a moderator: Feb 11, 2014
  19. pexhouse

    pexhouse New Member

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    I found the beginning VERY interesting because he shows figuring up the developed length included what was under the lawn (from the water meter to the front of the house). On the phone when I was going over what I had I gave him the parts of my addition (meter to house, house to water heater, water heater to furthest hot fixture) and he told me that the total developed length didn't include the part from the meter to the front of the house. :confused:

    On the phone he said the plumber had one of the state inspectors with him today and apparently he agreed with what was going on or something. I don't remember the exact words but that was along the lines of how he worded it to me. So I'm guessing I won't ever get this sorted correctly out so I'll probably just end up with the deal that was handed to me today and just drop it. I don't feel it's right but I'm the little guy and sometimes that's the way it goes.
     
  20. Reach4

    Reach4 Well-Known Member

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    Do you feel you understand just what they are offering to do, in order to reach an accord?
     
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