Dead leg problem? Outside tap removal, but pipes are underground...

Discussion in 'Plumbing and Central Heating' started by DIYNotIan, 8 Nov 2021.

  1. DIYNotIan

    DIYNotIan

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    Hi all

    Got a very old looking outside tap at our house which is not in use. A plumber is visiting soon to do a bathroom refit, and whilst here will remove the tap and cap it off. I asked whether this would cause a problem with a "dead leg" and he said no, but I want to check with you guys here please.

    The tap is behind a fake door which is just there for aesthetics as it's bricked up behind. I guess the tap itself is a dead leg isn't it? If so, shortening it can only be a good thing, but is it enough?

    The last photo shows the water meter cover in the ground. So the tap isn't far away from that. There are two stop cocks in the house, neither of which are near the meter or outside tap. One is around 8 metres to the left and the other about 10 metres to the right (both in the middle of the house, not on the outside wall you're looking at). So I've no idea at all where or how the outside tap is connected, if/where it is tee'd off from, etc. Also, a you can see there is a slab of old concrete in front of the door. Plus the oil pipe is underground somewhere between the meter and tap, which would make digging a little more of a pain.

    Goes without saying that the cheaper and easier option is preferable, but at the end of the day I want it to be right and most importantly I want my drinking water to be safe.

    To dig or not to dig (cap and forget)... That is the question?

    Many thanks for any help :)


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  3. Madrab

    Madrab

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    Any extended pipe that isn't being used is a dead leg. If that was looked at as part of a legionella risk assessment then that would be flagged up.

    How much of a risk is it, probably very low but it isn't zero. Just run the water clear for a minute, once a month.
     
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  4. DIYNotIan

    DIYNotIan

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    Many thanks @Madrab

    I presume you mean at the outside tap to remove any water that's been stagnating? Do correct me if I'm wrong though. But if I'm right I guess it seems the dead leg is a potential cause for concern and as suspected I need to either dig to find the source and have it capped there, or keep the tap but run it periodically to remove any stagnant water...

    Hmmm, tough decision. We need to do something with that wall behind the door at some point, to insulate it better, and tidy it up. When we bought the house the surveyor outlined what he thought needed doing there (I'll have to get the report and check what he said). Also, I think it's one of the spots where mice are getting in. The dog certainly likes sniffing around at the spot! Furthermore, the tap and pipe work looks pretty old and knackered, although that's to my untrained eye :) But for those reasons I thought best to get rid of it. But now it seems that that's not going to be such an easy job.
     
  5. Madrab

    Madrab

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    Yes.
    Ideally it would be removed but as you suggest it's considering what is the worst of 2 evils .... tracing it back to where it branches off the used mains and capping and the effort needed to do that or just remember to run and clear the pipe on a regular basis. Don't forget winter too, in case it's a freezing risk.
     
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  6. RandomGrinch

    RandomGrinch

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    Hi,

    Silly question, but have you turned both stop taps off and does the tap still work?
    Pipes have a funny way of ending up all over the place! :)
     
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  7. DIYNotIan

    DIYNotIan

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    I think that's a good question actually :) I'm at work now but will try it when home and see what happens. Many thanks

    Yes, we've had it insulated previously. I had some spare rockwool and just stuffed the whole cavity with it. Removed now just so that the plumber could see it when he came to quote... Thanks for the thought though.

    Cheers
     
  8. Harry Bloomfield

    Harry Bloomfield

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    From a Legionella point of view, you would be better keeping the tap and running some water from it once per month, or cutting the pipe back to where it originates from. I also note that is what appears to be lead pipe feeding it. Most lead pipework has been replaced due to the risk of lead poisoning.
     
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  10. DIYNotIan

    DIYNotIan

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    Thanks for the reply and also for pointing that out. Lead pipe? Oh dear. Well that would give a much stronger case for tracing back underground and getting rid of it properly if so. Is there an easy way to tell whether or not t's lead? Would a clean up be enough to tell visually?
     
  11. Harry Bloomfield

    Harry Bloomfield

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    Yep - if you scrape lead, it will be very soft and silver in colour. Copper is harder and yellow/gold.
     
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  12. JimCrow

    JimCrow

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    That pipe going to the tap is copper.
     
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  13. tell80

    tell80

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    the pipe is copper tube - its not lead.
     
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  14. tell80

    tell80

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    if you look down at the external water isolator it will show what type of material the main water supply is - the mains not any branchs.
     
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  15. DIYNotIan

    DIYNotIan

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    The main supply comes in through plastic pipes, at least where I can see it it does.

    I think when I've got some more time digging and removing it properly is the best solution.

    Thanks for all the help.
     
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