John Smith wrote:

My upstairs toilet still flushes, but the water doesn't leave fast, so that
the bowl fills up and empties slowly, and ends up less full (of water) than
usually. It also gurgles (outside where the vertical drain-pipe is) halfway
through.
I have a heavy vertical iron drain-pipe outside, which has the bit that
sticks up in the air for venting. At the bottom, there is a horizontal
underground run for about 3 meters, at the end of which is a manhole where
everything seems ok.
I worry that the underground bit has collapsed, and I will not be able to do

It may be blocked there, but that is perhaps less likely since the water
etc will reach that bit at a fairly high speed and with some force. You
could presumably check that section by rodding up it from the manhole.
Assuming you can push a rod along the underground section (use a worm
thread on the rod so you don't compact any blockage that might be
there), then the blockage is more likely to be closer to the loo.

that myself. I also generally worry about the heavy iron venting pipe (in
case it falls), which is right over where we sit outside in the summer.

If you have ever tried to get a cast iron pipe off a wall you would be
less worried about it falling all by itself! They are typically "nailed"
with heavy four or five inch studs into wooden plugs that are built into
the wall. Typically they are very secure.

Questions:
1. What is likely to be wrong ?

Blockage nearer the loo is likely - round its trap or in the pipework
immediately afterwards. Assuming a rodding operation from below has not
helped, then it is perhaps time to don the rubber gloves and see if you
can feel anything round the u bend....

Good dose of caustic soda would help shift anything organic that might
be causing a blockage.

Does the loo connect directly to the vertical section of the soil stack,
or is there a latteral run to reach it?

2. What can you do if the underground bit has collapsed ?

Dig it up and replace it.

3. How heavy is the iron pipe likely to be (per foot), if I want to try to
take it down myself ?

Pretty heavy... 5kg / foot perhaps (pardon the mixed units)?



--
Cheers,

John.

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