I want to redo the plumbing of my water pipes under the house. My house was built in 1927 and has galvanized?

pipes. I want to replace it with pex. I know little to nothing about plumbing. Do I just follow the route of the water lines now and I'm good? Or can I change their path slightly to use less pex? Like I said, the house is old and the old plumbing has a few unnecessary twists and turns. Any help would be great. Try to keep it in simple terms (or explain terms). Think as though you are writing "Plumbing for idiots."


7 Answers

  • 8 years ago
    Best Answer

    Take heart. Every plumber asked the same (or similar) questions when he first started.

    Okay, there are some ground rules you need to be aware of.

    1. No structural member (studs, joists, etc.) are to be cut unless absolutely necessary. Then, the hole for the plumbing will be no larger the 1/3 the depth/height of the stud/joist and will be placed in the center of the structural member.

    2. Plumbing will always be run in a warm zone. If you must run plumbing along an outside wall, make sure the insulation is between the wall and the plumbing. If plumbing must be run in a cold zone, it must be insulated and the cold run must be as short as possible.

    3. Every plumbing fixture (sinks, bathtub, shower, toilet, etc.) and appliance (washer, dishwasher, etc.) shall have its own isolation valve for each supply line to that fixture/appliance. This includes the water heater. Ideally, the isolation valve(s) should be near the fixture/appliance they control.

    4. Plumbing must not be run next to electrical wiring. Keep them separated by at least 12 inches or more, if possible. If plumbing is run in a wall parallel to electrical wiring, the plumbing should be under the wiring, not above.

    5. For valves, I prefer 1/4 turn, steel, ball valves. They are quicker acting and more reliable than the older, multi-turn, gate valves.

    6. When you get done with your plumbing, do a pressure check of the entire system. Open each faucet to purge air out of the system, then shut everything down. Go along the whole plumbing system checking for leaks, no matter how small.

    Source(s): Experience
  • Dan H
    Lv 7
    8 years ago

    You can take the shortest route necessary to save on pipe. Remember that galvanized piping is rigid and doesn't go around corners. it only makes 90 degree corners, so the path has to follow those rules. Pex will describe a curve, though not a tight one, so that makes it easier to run it.

    There are at least two different crimp type connectors for PEX. Each requires it's own specialized tools. You can also use quick connectors like Sharkbites. At some point, though, you do have to go back to copper for some connections so you will need to know how to solder copper for those connections.

    Getting up into the walls can take some work too, unless you are just replacing the long runs under the house.

  • Debra
    Lv 4
    4 years ago

    Any time you are talking about digging out the underground pipe, it's a huge job. How to dig faster -- use a machine -- which is why a plumber, whose time goes for $85 ++ per hour, and has customers waiting, will rent the machine, get it dug up in an hour, and then spend a couple hours on the plumbing and leave you to find a carpenter to fix up your floor. The handyman, who charges you $10-20 per hour, will be happy just to have the hours of work, and so he digs it by hand. How fast can you do demolition / dig? Is the plumber going to get the new concrete to dry faster? Tools and an inventory of parts make all the difference. If you wanted the job done by a certain day, you should have told him. He probably just didn't bring the valves / soldering tools with him on a day he was pouring concrete. Stop whining about your hotel bill - next time find a friend who will put you up, or else ask the neighbor if you can use their shower / toilet and stay at home during the work. Oh, wait, that would be too much inconvenience for the average modern American to bear!

  • Anonymous
    8 years ago

    Some other considerations are the size of the pipe, the number of fixtures served and the available water pressure. If water piping is too small and the water pressure is marginal, you get the situation where you flush the toilet and someone else that's taking a shower gets upset. PEX is probably a good choice. You can buy whatever PEX tools you might need then sell them on ebay when you're finished.

    Maybe you can find some sizing info here:


  • How do you think about the answers? You can sign in to vote the answer.
  • 8 years ago

    Take the shortest and easiest route. If you have any question make sure you visit the Home depot. The usually have a licensed plumber on staff that can help you.

  • donnyv
    Lv 6
    8 years ago

    I can suggest some but first whats pex?, pvc is a common replacement for galvanized or copper. proper setting times for glues is a key factor and cutting corners can get you in trouble. watch your pressure from the meter . pipes make noise when they have air in them and it results in hammering, check your codes , your not dealing with a yard sprinkler system

  • 8 years ago

    Shortest easiest is always the best.

    Source(s): Did mine it was oogly under there,
Still have questions? Get your answers by asking now.