Deteriorated Soil pipe advice

Discussion in 'Plumbers' Talk' started by Solidair, Mar 23, 2019.

  1. Solidair

    Solidair Member


    Wondering if anyone can offer an opinion here.

    My soil pipe (pics below) seems to get moisture around the joints when it rains. I have rodded the pipe up to roof and below ground to rule out blockages and backing up. (Recently had to dig out and replace the clay rest bend which had also cracked so the hole is still open).

    However, I’m now not sure what the cause and best fix is.

    At the timesaver joints the gaskets are a bit old but not terrible so I’m not sure this is the issue for them. (Side note: Can’t seem to find any trade places to buy gasket replacements without getting the whole cast iron part so it’s costly if it’s not required).

    I’m now wondering if the higher up joint (first pic) is leaking and the moisture is running down the back of the pipe to the timesavers, or if it’s just the actual pipe section generally deteriorating.

    Swithering if I should try and remove the lower section of pipe (above the timesaver) and get a good look at it. There’s no spacer between the pipe and the building to be able to see what condition it’s in at the back.

    What would you recommend?

    Are there any books/guides on this type of thing you’d recommend? Everything I’ve found so far doesn’t go into depth on scenarios like this, it’s all a bit more general about how old house drainage is set up, rather than fixing scenarios.

    Cheers in advance for any help!

    Attached Files:

  2. Heat

    Heat Well-Known Member

    That is cast iron soil stack I believe.
    Vertical joints just will be getting rain water into them, unless under pressure and leaking if sewer ever blocked.
    The joints could be just cleaned out as best as possible at top and sealed with a decent weather resistant sealant.
    Or get the entire stack replaced with plastic, but warning - cast iron is extremely heavy and would need expert removal and possibly scaffolding.
  3. Wayners

    Wayners Well-Known Member

    Replace with new not an option? Dose it have to be iron
  4. rogerk101

    rogerk101 Well-Known Member

    If it were mine, I would dig/scratch out whatever old sealant you can get to in each joint ... to the point that you have a good hollow. I would then give it a thorough clean with a wire brush (either regular hand held or on the end of a drill). Then suck it all clean with a vacuum cleaner, before filling with a good, exterior grade filler (something like sika flex). It's highly unlikely to leak after that. Much quicker, easier and cheaper than attempting anything drastic like replacing it all with plastic.
  5. KIAB

    KIAB Well-Known Member

    Replace the whole stack with plastic.
  6. Solidair

    Solidair Member

    Thanks very much all!

    Yeah, it’s some sort of conservation area (or similar) so it’ll have to be cast iron.

    I’ll get stuck in about the joints with some sealant and see how that goes.

  7. KIAB

    KIAB Well-Known Member


    Look at Brett Martin or Polypipe plastic cast iron pipe,have used it on several listed house without issues.
  8. dobbie

    dobbie Well-Known Member

    Get a mirror and look round the back of the pipe,I have come across where thy have got very thin and pinholed at the back.
  9. Solidair

    Solidair Member

    Thanks for all the suggestions, I cleaned out the joint at the weekend - was surprised how much stuff came out of there - and sealed it up again. (Pics attached).

    It doesn’t seem as bad but unfortunately on the first proper test this morning it's still leaking so I think it’s perhaps a pipe failure, there is a line of at least surface rust at the back but no way to see/tell if it’s pinholed even with phones and mirrors, there’s no spacer between the pipe and wall unfortunately).

    I’m going to get a pal round with some scaffolding to help remove it and have a closer look. Is there a recommended way to get the pipe out without cutting in case it’s ok after all and I just need better access to the joint? Planning to fit a spacer at the back whatever happens so at least I can access the back of the join in future.

    With regard to the hooks holding it on, do you normally have to just cut those and fit new ?

    (If anyone can recommend a book/step-by-step for this I’d be grateful. I’m going to do it slowly and VERY carefully but would like to read up on it first).

    Cheers again for all the input!

    Ps. KIAB, ta for the links, I’m checking on conservation area with Council, they seem to prefer like-for-like materials under their online planning guidance but have asked for clarity if it’s just a preference and lookalike will be ok in case whole stack needs redone.

    Attached Files:

  10. mcooper2406

    mcooper2406 Active Member

    Not a professional only going off what our builder told us but some of those old cast iron pipes have asbestos rope in the seals so bare that in mind if you do decide to change it.
  11. Solidair

    Solidair Member

    @mcooper2406 Thanks for the heads up! Have only seen old putty/sealant so far but will bear that in mind.


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