How long after water is shut off can plumbing work be done?

Discussion in 'Plumbing Forum, Professional & DIY Advice, Tips & ' started by dayexday, Sep 19, 2012.

  1. dayexday

    dayexday New Member

    Messages:
    12
    Location:
    new york
    I live on the 11th floor of a building and need the building to shut off water so a plumber can replace my shower valve. The plumber is being paid by the hour. How long after the building shuts off the water can the work commence? He says he has to wait at least an hour after the water is shut off until he starts.
  2. kreemoweet

    kreemoweet New Member

    Messages:
    371
    Location:
    Seattle. WA
    Must be Union Rules.
  3. dayexday

    dayexday New Member

    Messages:
    12
    Location:
    new york
    hmm, so there's no real need to wait?
  4. DaveHo

    DaveHo New Member

    Messages:
    53
    Location:
    SE PA
    He'll need to wait for all the water above to drain out, but other than that there's no other need to wait.

    I'm more amazed that each unit does not have it's own shut-off. That stinks for all the other residents.
  5. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,315
    Location:
    Cave Creek, Arizona
    He can start work as soon as he is able to control the water inside the pipes. Sometimes that means immediately if he can stop the flow long enough to install control valves, or a long time if he has to wait for all the water to drain down from the higher levels. In addition, water working the way it does, even after he starts to work if someone higher up opens a faucet and breaks the suction holding the water in their pipes, it can flow down and interfere with the work he is doing.
  6. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    21,832
    Location:
    New England
    There are ways to make this faster, but not everyone has the tools to do it. There are machines that can freeze the pipe to block water and there is a tool called JetSwet (may not have that spelled right for their trade name) that, once you have the water off, you can use that tool to block the water immediately. You'd use that to install an intermediate shutoff valve, then do the rest of your plumbing, while the rest of the building has water restored. You could cut the pipe and insert the JetSwet almost immediately after the pressure was off as it acts like a valve to hold the water back while you install a new valve. Once it is soldered in, you can remove the JetSwet, shut the new valve, then turn the water back on and then complete the rest since you now have a new, local shutoff. You just can't solder things while there is a constant drip of water in the pipes, and stopping it can take a very long time (or not).

    You may be on the 11th floor, but if there are lots of floors above, it becomes a bigger unknown as HJ said. Think finger over the end of a straw...someone opening a valve above can release water that was trapped. Since valves are not all created equal, under vacuum, they may leak while not leaking under pressure, then, if someone has a leaky faucet or say toilet valve somewhere above you, it could leak for hours.

    To give you an idea, here's the instructions for the JetSwet... http://www.brenelle.com/index.php?type=how

    Depending on the hourly rate, if he didn't have one, it might be cheaper to buy one and let him use it so he wasn't sitting around twiddling his thumbs (but, depending on the scope of the job, he may be able to prep other things while the water stops dripping.
    Last edited: Sep 20, 2012
  7. Winslow

    Winslow Plumber

    Messages:
    450
    Location:
    Hawaii
    Depends on where he is in relation to the bottom of the stack and how many floors are above him. He may be giving his estimated time based on prior experience in the building. Sometimes shutting the water down can be a time consuming operation in itself, shutting down pumps and so forth. Sometimes there are no isolation valves on individual stacks or they are old gate valves that don't hold so the entire building has to be shut down and drained.
  8. Winslow

    Winslow Plumber

    Messages:
    450
    Location:
    Hawaii
    Freezing the pipes would work but you need enough room to be far enough away from the freeze point that the heat doesn't melt the ice block before the joint cools. Generally speaking it's not a good idea to freeze the pipes unless there would be no damage if the freeze didn't hold.
    A jet sweat would be out of the question unless you plan on using it after the majority of the water is drained and you use it to stop the residual you get from stacks. It will cut some time but the water still needs to be drained first.
    There is a third option called an add a valve that can be installed on a pipe under pressure and then is just buried in the wall when finished, ut it is an expensive option
  9. johnjh2o1

    johnjh2o1 Plumbing Contractor for 49 years

    Messages:
    1,142
    Location:
    South*East
    Many codes don't allow valves to be in nonassignable areas. Are you sure there isn't a valve for your unit? Chances are in a building that tall there is a pump system and that would require PRV valves. There should be a main valve before it to allow for servicing.
    John
    Last edited: Sep 21, 2012
  10. Winslow

    Winslow Plumber

    Messages:
    450
    Location:
    Hawaii
    If the valve needed to be accessed then by code it cannot be buried. However a valve that has no other purpose but is a temporary measure wouldn't fall into that catagory. Newer buildings generally have isolation valves but in years past it wasn't considered a necessity. The only high rise I saw with PRV off the stacks where the water was fed down from the roof. They didn't have a conventional PRV but a specialized valve for that purpose with no isolation valve. Even then there wasn't one installed on every floor. The stacks are usually zoned and each zone has it's pressure set individually for it's zone. It's possible in this case that the bottom zone covers the first 10 floors, then he would be on the bottom of the stack in his zone. There are too many variables involved to make a distinction of how to address his particular situation.
  11. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    21,832
    Location:
    New England
    The JetSwet specs say it will hold at up to 65# of pressure, depending on the height of water above, after you've turned off the supply, it should hold. If you let out the initial pressure and had other valves in the room open, while it would be messy until you got it in and sealed, you should be able to do it. You would need access to the new valve, which might be a problem.

    If there's a place where you could shut off all the water to your unit, rather than do this in your bathroom, you might install it there. Then, you'd be able to do maintenance easier in the future without having to shut the building's water off.
    Last edited: Sep 21, 2012
  12. johnjh2o1

    johnjh2o1 Plumbing Contractor for 49 years

    Messages:
    1,142
    Location:
    South*East
    Many high rises around here are fed with a booster pump system that requires PRV valves on the lower floors. And as far a valve goes whatever there used for isolation or not they can't be behind walls.

    John
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