Waste pipe leaking through wall

TheGreenFrog

I have a bathroom waste pipe (pic attached - the pipe serves two adjacent bathrooms which are on slightly different levels) which is leaking.  There does not seem to be any leaking inside the house - it seems to leak somewhere inside the wall (which is solid) or outside.  I don't know how the piping fits together so don't know how to trace the leak.  

ThisIsWeird

Can you get right up to it safely using a ladder? If so, I'd take some kitchen paper, and thoroughly dry that area around where the pipe comes out the wall.

Then examine it closely, using a torch if needed (as it can give a shiny reflection), whilst someone drains water.

You want to find out if the water is seeping out from the hole in the brickwork or from where the small waste pipe joins the round collar going to the stack.

I can't tell, but I'm guessing that the 'collar' (yellow) is part of the 4" Tee-piece? If so, it'll likely have a rubber O-ring in it, and the waste pipe existing the wall just goes straight into this.

Can you see any of the waste pipe as it exits the wall - orange arrow?

TheGreenFrog

Thanks - will investigate at w/e (weather permitting!).

Le_Kirk

I agree with @ThisIsWeird, that collar looks distorted.

grumpy_codger

Doesn't look like collar to me. Can it be some piece of bigger diameter pipe that the waste pipe goes through?
If it's really a collar, then the pipe seems to be misaligned very badly.

Section62

TheGreenFrog said:

Thanks - will investigate at w/e (weather permitting!).

Are there any brackets (pipe clips) supporting the stack?  I agree the most likely thing is the boss connection coming apart or being distorted, but that in turn may be due to the weight of the stack excessively loading that connection - if you fix it the same thing is likely to happen again.

The way the connections have been done is a bit of a bodge - there is excessive weight caused by the WC connection from the left, and movement in the pipes will impose loads on the pipes they aren't really intended to take.

Section62

grumpy_codger said:

Doesn't look like collar to me. Can it be some piece of bigger diameter pipe that the waste pipe goes through?
If it's really is a collar, then the pipe seems to be misaligned very badly.

Compare it to the boss for the waste pipe coming from the left...

TheGreenFrog

Just wondering what trades fix this kind of thing.  Assuming a plumber?

stuart45

Yes, that's the plumber's job.