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Discuss Bath P-trap Inlet Lower than Outlet in the Fittings & Pipes area at UKPlumbersForums.co.uk.

  1. Billy Whizz

    Billy Whizz New Member

    Hi all,

    Just fitted a new bath (height fixed due to bath panel). Plughole mechanism now means the bath waste connection is an inch lower than the original and hence there is no fall on the wastepipe. Soil pipe connection cannot be lowered to compensate.

    How can I raise the P-trap outlet higher than the waste inlet to reproduce the fall on the waste pipe again?

    Many thanks & best regards,

    BW

    20170717_122500.jpg
     
  2. PAUL JA

    PAUL JA New Member

    • Like Like x 1
  3. Billy Whizz

    Billy Whizz New Member

    Thanks Paul JA. A little too long unfortunately. :-(
     
  4. JCplumb

    JCplumb Plumber

    How long is the level run of pipe?
    If it's only a foot or two you should be OK, I've seen much worse perform well, much longer than a couple of feet and you will need to adjust it. If the fitting posted above fits then that will do fine as long as it doesn't increase the water level in the trap too much. If it does raise the water level too much, you could use an adjustable trap to get the level right. You only need approx 1cm per meter drop on the pipe.
     
  5. Best

    Best Trusted Plumber Top Contributor!!

    Is the waste pipe level and how far does it travel at level (or wrong fall) ?
     
  6. JCplumb

    JCplumb Plumber

  7. Best

    Best Trusted Plumber Top Contributor!!

    Adjustable trap will probably not be any use as it only normally allows trap to lower, but not go higher than standard traps. But some do vary.
     
    • Agree Agree x 1
  8. JCplumb

    JCplumb Plumber

    In conjunction with the item linked in the first reply.
     
  9. oz-plumber

    oz-plumber Plumber

    Might be a case of making a trap out of solvent welded fittings.
    We do this on occasions when in a similar situation.
     
  10. PAUL JA

    PAUL JA New Member

    • Like Like x 1
  11. Stigster

    Stigster Plumber

    • Like Like x 1
  12. Billy Whizz

    Billy Whizz New Member

    JCPlumb/Best,

    The pipe run is 1.2m and is currently falling 3cm towards the bath (the wrong way). If I can raise the outlet until the pipe run touches the first bath support rail (adjacent to the trap in the first image) it will at least bring it level.

    Will have a go at some of the shorter McAlpine couplings.

    Oz-plumber,

    I had considered the welded fittings but would rather something that can be unscrewed if needed.

    Sigster,

    Tried one of those. Looked good but not enough clearance due to adjacent floor-level bath support.

    Thanks for your input guys, plenty of food for thought..

    Best regards,

    BW
     
  13. JCplumb

    JCplumb Plumber

    With an adjustable trap and the extension piece in the right place you can control the height of the trap exit to get the waste pipe exactly where you need it.
    Here's a hi-def photo of one I did earlier. I used the same camera I used to photograph my wedding so the quality is awesome.
    The arrow on the left is where you adjust the trap which will raise lower everything else to where you want it.
    The pink bit is the extender that Paul JA linked on the second post.
    The waste pipe is green because it's now in the right place :D
    amazing diagram.png
    But the McAlpine trap that Stigster linked above may also work ;)
     
    • Like Like x 1
  14. Michael1960

    Michael1960 Plumber

    Use a dry trap inline, come off of waste with a 90 and put a dry trap in.
     
  15. Billy Whizz

    Billy Whizz New Member

    Thanks everyone for your suggestions.

    In the end, Paul JA was right with the 1" coupling fitting. Initially it didn't fit but that later turned out to be due to a minor manufacturing difference between the new McAlpine coupling and the old original trap. Having purchased a McAlpine P-trap to match the 1" coupling, it all fits sweet as a nut, I have a level waste and the bath empties nicely. The best I could hope for under the circumstances. :)

    Many thanks once again y'all.

    Best regards,

    BW

    20170723_124145.jpg
     
    • Like Like x 1
  16. kris

    kris Trusted Plumber GSR


    Second this , this is exactly wot needed
     
  17. kris

    kris Trusted Plumber GSR

    Was there always a hole in the floor or was it made for new nbath
     
  18. Billy Whizz

    Billy Whizz New Member

    No Kris, it was already there from the previous bath. And as I mentioned previously, that trap with the rodding point would not fit under my bath due to adjacent fittings. :)
     
  19. Harvest Fields

    Harvest Fields Trusted Plumber GSR Top Contributor!!

    Can you not use this??

    IMG_9121.PNG
     
  20. Billy Whizz

    Billy Whizz New Member

    Thanks Harvest Fields, but no. This trap has been suggested previously but the outlet was still the same level as the inlet. :):)
     
  21. Harvest Fields

    Harvest Fields Trusted Plumber GSR Top Contributor!!

    But surely the same is better than worse then. However maybe one of the other ones mentioned above will work?
     
  22. ShaunCorbs

    ShaunCorbs S. Mod Trusted Plumber GSR Top Contributor!!

    It's all sorted now i believe
     
  23. JCplumb

    JCplumb Plumber

    If there's any length to that horizontal run make sure it's supported.
    Would be wise to dose with something like soda crystals once a month too to stop any build up in that horizontal length. Don't buy one shot or any other chemicals, an 80p bag of soda crystals will keep it clear for a couple of years. Couple of teaspoons dissolved in a pint of hot water, bung it down the plug hole, flush it away 30 mins later.
    *edit*
    Health and safety disclaimer:
    Follow the instructions on the bag. :)
     
  24. Harvest Fields

    Harvest Fields Trusted Plumber GSR Top Contributor!!

    What did he use in the end?
     
  25. ShaunCorbs

    ShaunCorbs S. Mod Trusted Plumber GSR Top Contributor!!

    1" high male to female adapter (mcalpine)
     
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