View Single Post
  #6   Report Post  
Alasdair
 
Posts: n/a
Default undoing cast iron soil pipe joint

"BigWallop" wrote in message ...
"Alasdair" wrote in message
om...
(OldScrawn) wrote in message

...
I agree with Andrew but suspect in this case the right option would be

to lose
the accessible bit of iron and replace with plastic. Probably start with

an
angle grinder. I've used the little slitting wheels on "dremel" type

tools to
slit the remains of the inner tube without threatening the socket, or

just to
put in a stress raiser so that it cracks without applying too much

force.

Thanks for that. A further question.

I don't think the cast iron pipe is 4". I appears to have an external
diameter very similar to the internal diamaeter of the 110mm plastic
pipe.


If the 110mm diameter is at the spigot on the end, then pipe is classed as
three inch. There is no way you get a 110mm (4'') pipe into it, or an
adaptor that goes the wrong way round, i.e. 4'' on top to 3'' on the bottom.
Although there are reducers that will go from 3'' above to 4'' underneath.

(see below)

Whats the best way to make the connection? Perhaps I need an adaptor
that will smoothly reduce the 110, and fit internally to the cast iron
pipe? or can I just slip the plastic pipe over the cast iron stub and
seal it up?

Also, is the cast iron likely to be a 3.5" internal diameter? Its
marked with a "C" if that is of any use!


Thanks,

Alasdair


What are you connecting to the stack ? What is already connected to the
stack ?


Hopefully the below ascii picture will explain.

+ -thin partition wall
+
: c : +
: o : +
: m : +
: u : +
: n : +
: u : +
: a : +
: l : + **** ====
: :********* ===========
: s pipe A pipe B - WC connects here
: o :********* ===========
: i : + **** ====
: l : +
: : +
+
+
I am on the ground floor, the communual soil is vertical and pipes A
and B are just off horizontal..

I want to remove pipe B from Pipe A, and replace Pipe B with a new
plastic one.

Pipe B:
Cast Iron
~110mm External diameter along its main length
(The socket at the end is much wider and accepts the WC)
Unknowen internal diameter.
Marked with the "C".


The question is, how best do I attach the 110mm plastic pipe to pipe
A.

Options seem to be.
1) Cut Pipe B in half and graft a new plastic pipe to the Stub.
2) Dig out the lead fixing pipe B into Pipe A, remove pipe B and and
fit the new pipe into the socket.


for 1), The question is, is this a wise thing to do, and if it is, how
exactly should I form the join?

for 2), having had a look there are about 4cm of lead to dig out, so
that's very hard in its self, and then the question is again, how
exactly to make the join?


Any help on this is very much appricated. I'm not absolutly opposed to
getting a professional plumber in if thats required, but I'd rather
crack it my self.

Thanks,


Alasdair