Adding new drain line to neighbours manhole

Discussion in 'Plumbers' Talk' started by Westerosijosh, Jul 8, 2021.

  1. Westerosijosh

    Westerosijosh New Member

    Hi all, I’m after some advise on connecting into my neighbours manhole with a new drain line from a WC I’m adding to the front of my house in a porch. The problem with doing this is the position which it will enter the manhole is the opposite side to the direction of flow from the neighbours ( See picture.The red arrow indicates the existing direction of flow, the green is the position from where I intend to enter from my property).
    I want to know if it is at all do-able, or will it cause problems to the existing direction of flow, and if so what would be the best way to do it. There is plenty of fall for my pipe as this manhole is a metre down so would I be best to use a drop drain into it from say half way down or is it best to enter from right down at the bottom.
    I hope I’ve explained this well enough.
    Thanks in advance.

    Attached Files:

    Last edited: Jul 8, 2021
  2. dray

    dray Active Member

    I'm not a builder but I am pretty certain it would cause all sorts of problems going against the flow. I am guessing that you would have problems with getting pipework approved as well, assuming you are going for compliance with statutory authorities etc?

    I am intrigued though, you do sound as if you have the right to do this, but is your neighbour happy for you to trench across their property to try to get into the manhole and do they know that it could cause them problems?

    Have you thought of a new downstream manhole on your property so that your pipe can join with the flow?
    Good luck with it though and hope you find a solution
    Westerosijosh likes this.
  3. nigel willson

    nigel willson Screwfix Select

    Simples, you can’t enter from the wrong side for flow reasons! You would have to come round one side so that flow direction is maintained. You would also need to comply with local building regs with local council
    Westerosijosh likes this.
  4. Jim Kirk

    Jim Kirk Member

    Where are you located - legally this cannot be done in Scotland. Your neighbours must be mad to allow you to do this and would cause them serious problems if trying to sell their house - as a minimum it would have to be recorded in the titles to both properties.
    Particulary with a WC you will be dumping solids on top of the benching - the neighbours would need to flush their toilet everytime you used the WC. You need to consider options to use their own drainage even a Saniflo
    Westerosijosh likes this.
  5. Westerosijosh

    Westerosijosh New Member

    Yes I’ve asked my neighbour and he’s fine with it, it’s pretty much next to the boundary fence anyway so not having to dig far into his property, it’s about a metre. I’ve also been in touch with BC to ask if I need permission from the water company as it’s on a neighbouring property and he said they would just pass it back to BC anyway so as long as it’s done properly it should be fine, although they haven’t yet been out to assess it. I have explained it in an e mail and they said it shouldn’t be an issue but, like you I think it will cause a problem going against the flow.
    If I came from the other direction, left of the picture then I would be digging up a lot more on my neighbours property and would have to put another inspection chamber in for the change of direction.
    Our existing soil pipe is at the rear of our house and leads into our other neighbours manhole -we don’t have one as we are the start of the run- and that neighbours man hole is only about 2 ft deep so to route a new pipe all the way from the front of the house to the back in just not going to get the fall I need. It’s an absolute pain cos we are on a corner plot but I can’t see any other solution. Thanks for the advice anyway
  6. Westerosijosh

    Westerosijosh New Member

  7. Westerosijosh

    Westerosijosh New Member

    Thanks for the advice, none of this was explained to me by building control, he seemed pretty blasé about it.
    based on this I think I need to press them some more on regulations etc but I think it’s back to the drawing board, if there’s any chance it’s going to cause problems for my neighbours then I won’t bother trying. Thanks again
    candoabitofmoststuff likes this.
  8. Jim Kirk

    Jim Kirk Member

    OK if the permissions are OK - suggest to take your drain as far across the manhole as possible and turn with a large 90 bend and a 45 bend (if space) or 3 x 45 bends (not a short bend and a 45) - to line up into the channel in the direction of flow. Do not just dump it out the pipe or straight down out of a 90 bend on top of the benching or it will just build up in heap.

    Do not use a two stage flush or water saver setting on the toilet flush, full max flush only. Give the manhole a weekly check for the first two or three weeks to make sure its flowing and not filling up as because your inlet is higher up - any blockage will impact on the neighbours downstairs drains first.

    I fear however that without being confirmed in the titles any new neighbour could block this off without warning or comeback if it begins to cause problems.

    Good luck and best wishes
    Westerosijosh likes this.
  9. masterdiy

    masterdiy Screwfix Select

    That chamber doesn't look man enough for another waste pipe.
  10. Abrickie

    Abrickie Screwfix Select

    So the property at the end of a run can block everyone else’s drainage ? Nonsense, the private drain will become a shared sewer and the local water companies responsibility from the manhole down stream
    ElecCEng likes this.
  11. Jim Kirk

    Jim Kirk Member

    No - nobody can block the outlet of a common drain to the sewer! - I did not pick up on the fact that it was common drain, but if it is, it will be recorded in the titles and each owner will be responsible for a share of upkeep and maintenance, but an illegal non-compliant connection into a common drain or worse a neighbours private drain can be severed.

    A private drain even a common drain becomes a piblic sewer when it leaves the boundary of a private proprerty. A common drain does not become a public sewer when the drain crosses the boundary between one of the private sharing properties to the other.

    You cannot simply tap into next doors private drain system just because it is more convenient - even with permsion without burdens on the titles, otherwise the permission and the connection are not heritable upon subsequent onwers.
  12. Hans_25

    Hans_25 Screwfix Select

    I was of the understanding that a new device like a toilet would require a new manhole, cannot connect to an existing.

    It might be only for a new extension that has a toilet, not a new toilet in an existing building. Is the porch existing or new? Anyway worth looking into.
  13. stevie22

    stevie22 Screwfix Select

    You connect to an existing chamber if you can 'cos it's easier. Regs want access for rodding basically.

    In this case aside from the legal side I would go with a slipper bend and bring the new pipe in over the benching so as not to interfere with the existing flow. This is what I had to do at my place in a similar situation (though the target chamber was mine).

    Good points about flush size

    The key thing is to have a dialogue with your friendly BCO
  14. Abrickie

    Abrickie Screwfix Select

    ElecCEng likes this.
  15. Westerosijosh

    Westerosijosh New Member

    It is a new porch being built
  16. Westerosijosh

    Westerosijosh New Member

    Thanks all for your inputs, I’ve learned more on here than I did speaking to the building inspector!
    I’ve learned that it would be a whole lot easier if I could keep the work on my own property, it’s just as I explained before I really don’t think I’ll have the fall, I don’t even have an inspection chamber! My soil pipe at the rear of the house is only about 2foot deep.I would have to bring the new pipe all the way from the front of the house with 2 changes of direction, meaning 2 new inspection chambers, to connect to the existing.
    I’ve also learned that if I connect to a neighbours pipe, where it crosses the boundary then becomes the responsibility of the water company, for which I need permission.
    I’m going to scrap my original idea anyway, it seems it could cause flow issues so I’m not going to risk it.
    The only other option is to connect into my neighbours pipe further down, where there is no issue of upsetting the flow. It would just mean adding a new inspection chamber where I connect to it. Luckily I have amazing neighbours who have agreed I can do this. But would it be as straight forward as this? With regards to the legality of it?
  17. Abrickie

    Abrickie Screwfix Select

    You do realise that to call it a porch and avoid the need for planning permission and building regs for the build ( still needed for the drainage), you need to keep your existing front door and be 3 square metres ;)
    Westerosijosh likes this.
  18. Westerosijosh

    Westerosijosh New Member

    Yes I looked into that to see how I could get round not needing building regs. I don’t need planning permission but because I’m knocking out the existing front door, putting steel in etc and the drainage I need regs
  19. Westerosijosh

    Westerosijosh New Member

    Here’s a drawing to hopefully give you all a better idea of what I’m trying to do. Don’t all laugh at it too much! Yes I think my 8 year old could have done a better job of it! Obv the red is the original idea that I am now scrapping, the green is the new plan that I think will be better. Any thoughts appreciated

    Attached Files:

  20. Abrickie

    Abrickie Screwfix Select

    Pretty sure if you remove the original front door it’s an extension not a porch, just saying ;)

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