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Discuss 40mm PVC pipe to 110mm cast waste pipe in the Fittings & Pipes area at

  1. DIY Dad

    DIY Dad New Member

    Hi folks, I'm new to the forums and looking for a wee bit of advice. Having recently bought a new home I've found a leak under the sink which needs repaired.

    I have a 40mm PVC waste pipe going from the sink into a 110mm cast iron stack, which is packed with what I think is Plumbers Mate or something similar which is very soft and pliable (see photos):

    IMG_0363.JPG IMG_0362.JPG

    Advice from the guy in a local plumbers merchant is to dig out the sealant and repack it with Plumbers Mate, Putty or even silicone :eek: there any other simpler solution, like some kind of reducer to connect the cast to the PVC?

    Any help is greatly appreciated :)
  2. ShaunCorbs

    ShaunCorbs S. Mod Trusted Plumber GSR Top Contributor!!

    What is the dia of the cast looks more like 2.5-3" ??
  3. DIY Dad

    DIY Dad New Member

    It's definitely 110mm ...4 1/3"
  4. ShaunCorbs

    ShaunCorbs S. Mod Trusted Plumber GSR Top Contributor!!

  5. DIY Dad

    DIY Dad New Member

  6. snowhead

    snowhead Well-Known Member

    There will be a piece of copper or lead into that cast iron with the plastic connector onto it. I bet the condensate from the boiler hasn't helped.
    If that's 40mm plastic, then it's not 4" internal cast, it'll be 2.5 / 3 as Shaun said.
    The collar on the cast is about 15mm thick.

    You may end up using something like this, sizes would need confirming first over the outside of the cast;
    Fernco Adaptor Coupling 112-102 / 45-38mm Grey | Priority Plumbing
    Last edited: Jul 26, 2017
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