Need Advice Before Re-piping house

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by Underwater, Mar 24, 2013.

  1. Underwater

    Underwater New Member

    Messages:
    7
    Location:
    Illinois
    I have galvanized steel pipes, about 47 years old, and the hot water pressure is very low, even on the short runs. I can see where some leaks have been repaired in the past and there are some rust spots in other areas. I've been advised to change the horizontal supply lines first because they are easy to access, and then the risers if the problem still persists (idea is not to cut open too many walls unnecessarily).

    Questions are:
    1) Is this sound advice
    2) Could there be other reasons for the low pressure (the heat traps have already been removed from the water heater and the fittings cleaned)
    3) Is there a way to clean out galvanized steel pipes either with pressure, a chemical or mechanically to avoid changing the pipes?

    Thanks in advance
  2. kreemoweet

    kreemoweet New Member

    Messages:
    371
    Location:
    Seattle. WA
    Partial replacement is a bad idea. Frequently, old steel pipes simply cannot be removed without damaging the connected pieces, making total replacment of
    that branch necessary, but unplanned for. Frequently, partial
    replacement makes the clogging problem worse, due to rust and crud getting dislodged and moving into remaining pipes. Leaving steel pipes that old in place
    subjects you to middle-of-the-night leaks and sudden bad clogging, requiring unplanned for emergency repairs.
    There is no way to fix rusty old steel pipes short of replacement.
  3. Underwater

    Underwater New Member

    Messages:
    7
    Location:
    Illinois
    Thanks for the reply. Seems like a bad idea to me as well but the plumber says he does this all of the time. It's not a fly by night plumber; it's a family business that's been around a very long time serving a high end and demanding clientele.
  4. jm66208

    jm66208 Member

    Messages:
    99
    Location:
    KC
    If you are a gambler, follow your plumbers advice. You may win, you may loose...
    I'd follow Kreemowweet's advice and do it right the first time.
  5. Gary Swart

    Gary Swart In the Trades

    Messages:
    7,358
    Location:
    Yakima WA
    Galvanized pipes usually are good for 40 years. During that time, they corrode on the inside which cuts the carrying capacity of the pipe to the size of a pencil. Your problem is not low pressure, it is low flow. As already pointed out, you would be in a real crap shoot doing a partial replacement. I understand the concern about cutting open walls, but that where you are in my opinion. Some folks my recommend PEX, but that still requires access to the inner walls.
  6. Terry

    Terry Administrator Staff Member

    Messages:
    15,110
    Location:
    Bothell, Washington
    I don't do partial repipes.
    What a waste of time.
    Fortyseven years and most of the problem will be at the chrome plated brass shutoffs at the fixtures. The pipe nipples start to close off there. Galvy doesn't like being near brass. Replacing horizontals and leaving the old shutoffs in place? Really?
  7. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,797
    Location:
    Cave Creek, Arizona
    1. I have done it when galvanized pipes were leaking, because leaks usually occur in the horizontal lines, but low pressure is often caused by accumulations at turns which are most often inside the walls.
    2. Not likely
    3. There are companies which will "sand blast" the interior of the pipe and then epoxy line them. Usually more expensive than repiping, but much less invasive.
  8. Terry

    Terry Administrator Staff Member

    Messages:
    15,110
    Location:
    Bothell, Washington
    Once you start mixing galvanized and copper, the galvanized will go downhill even quicker. That's why on my repipes, I try to remove every bit of it.
  9. asktom

    asktom Member

    Messages:
    574
    Location:
    Victor, MT
    Type "L" and brass nipples all they way if it was at my house. Of course $ are sometimes a factor. Replacing the horizionals only is part one of the project and may get you by for a while, or longer, depending. As mentioned above, the nipples behind the angle stops are famous for clogging up, might want to change those too if you opt for only doing part one. Changing the whole shebang is the right way and gets it over with. No lurking.
  10. JerseyShore

    JerseyShore New Member

    Messages:
    13
    Location:
    New Jersey
    I am in the process of doing a gradual re pipe in a 1943 two family. I agree that partial re pipe is to be avoided, but due to an elder care situation, I cannot take down walls. I plan to finish the horizontals in the basement with copper and then move on to the risers with PEX. Hose bibs across the basement will be done in PEX to cut expense. So far the 70 year old galvanized has been in better condition that I originally thought. With about 60% of the basement done, we are experiencing better water pressure. However, this increased water pressure due to the new copper has on two occasions freed up rust within the remaining galvanized which cut water flow off. Scarey. The plumber was able to use a Shop Vac to blow air thru the pipes and blast out the clogged rust. In my city for a complete re pipe you need a permit and an inspection. To change pipes in stages, no permit is required, since this is considered maintenance here The most important thing I have learned from this is that the plumber is crucial to the success of the project. I am very lucky since our plumber is a true professional who has been there for us every step of the way thru a nerve wracking project. It is best to get rid of all the galvanized and not try to preserve it. Hope this helps and good luck!
    Last edited: Mar 26, 2013
  11. bluebinky

    bluebinky Member

    Messages:
    405
    Location:
    Santa Clara, CA
    If you are going to go with some PEX, why not just go with PEX. Once you get supplies to hot & cold manifolds, you can stub off and replace one run at a time -- at any pace you want...
  12. cacher_chick

    cacher_chick Test, Don't Guess!

    Messages:
    3,249
    Location:
    Land of Cheese
    Most houses can be re-piped without having to cut more than a one foot square hole at each fixture. It always baffles me when some guys take big sections of wall down to do a re-pipe.
  13. JerseyShore

    JerseyShore New Member

    Messages:
    13
    Location:
    New Jersey
    I have an eldercare situation so I can't take down the walls and have the water off too long. The jury still seems to be out on PEX. I am afraid I have no choice for the risers but to use PEX, but I am not crazy about putting hoses throughout the house. Also, I read somewhere there is a new virus or bacteria that thrives in plastic piping, so who knows what they will discover years from now.
  14. killforfood

    killforfood New Member

    Messages:
    6
    Location:
    Orygun
    Hey Underwater,

    I can totally relate to your problem. I just joined for the same reasons that you are here. I'm tired of cleaning the rust out of the faucet screens and shower cartridges. The galvanized nipples behind some of by brass shut-offs had to be replaced. When I put a pipe wrench to them, they just crumpled and the pieces had to be remove with vise grips and chisels. I'm pulling every ounce of galvanized out and replacing it all with Pex and maybe some copper at the stub-outs.
    Yesterday I started cutting all of the access holes in the sheetrock and one stud with a Sawzall. The vibrations turned my water to thick mud and clogged all of the kitchen fixtures again. GRRR!!! I HATE GALVY.

    Good luck with your project.
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