how to cut very tight cast iron pipe, advice needed please

[happyhero]

I am helping my fiend with his plumbing and we need to join a sink waste into the soil stack outisde which is cast iron for the first 8 feet or so. We thought it a good idea to change the bottom bit to PVC so that it is all PVC but it is so tight to the wall, and you can see the top of the clay pipe above ground which is nearly a third buried in the wall (see picture) God know why they installed it like this.

At first we were going to change the bottom section to PVC but because it is so close we then thought to use one of those chain cutters about 10inches up and use PVC from there but it does not look like there is enough room to do that even.

I have fitted a boss connector, to cast before and I know it was not that easy, it took a few broken drills and nearly burnt out my hole cutter, and we would prefer changing the cast if possible.

So what should we do? Would cutting it with a grinder be successful do you think, I would be worried on the cast moving and biting the grinder blade?

Hope picture is big enough, not sure how people get theirs to be zoomible on here.

Any advice or help appreciated.

 

[Agile]

My advice is not to get involved with a friend on a difficult job which can easily go wrong.

Either you are hoping to make money by charging him or you want to demonstrate your prowess at plumbing.

It would be far better to get a professional ( if you are able to find one who is so stupid as to take on a difficult job ).

The obvious solution is to do the absolute minimum which would be to drill a hole for the connection.

Tony

 

[picasso]

not really a difficult job to be honest, use a 4 inch angle grinder to cut a square (thats bigger than the grinder ) out the front of the pipe and then put the grinder inside the pipe to get to the back section.

 

[gasafengineer]

not really a difficult job to be honest,quote]

For someone who is NOT a plumber (agile) then the term 'difficult' is only to be expected , if you don't know then don't post , simples.

Problem here is the back of stack is pretty much against the wall , normally the chain cutters can be wrapped around the pipe & with a couple of pumps the pipe can be cut....................even when a section is cut out it will be difficult to install a boss pipe as the couplings will foul the brickwork , ok the brickwork can be cut but that would make for a shoddy job.....................best way forward would be to take stack down & replace it along with resiting of drain point , a fair bit of work but better in the long haul...................i can't see this happening somehow.

What about the plastic stack in the left of picture? , next doors?

 

[dcds4]

Smash the pipe with a hammer, wear goggles, the fact that the back of the pipe is against the wall should stop it breaking the clay

 

[Nige F]

not really a difficult job to be honest,quote]

What about the plastic stack in the left of picture? , next doors?

Indeed - or if it`s on the same property - and there is that 8 foot of iron stack tucked right tight in the opposite corner . I would be looking for a manhole - because I have a feeling that the one tucked close into the wall is actually an air inlet pipe that someone has decided to convert into a soil pipe @ some time in the past . No way would a conventional soil pipe with lugs have been able to run up the wall there -

 

[transam]

get afew sharp drills & drill a hole for a boss , drill a series of holes in a circle to correct diameter than increase the drill size , hammer & chissel smack it out , get a rodetal boss (they come in blk ) B&Q for some sticks like s**t , away u go , jobs a good en !

 

[Agile]

Of course its possible to do the job but its not a very suitable job for a DIYer. My advice is still to connect into the c.i. pipe.

Smashing it will almost certainly drop heavy pieces into the drain which may be difficult to remove. It might also crack the s.g. clay pipe.

My reasoning is that a job is best done with the least work and the least risk.

It does seem odd how its built into the wall. Nigel may be right or it could have just had the s.g. pipe fitted in the wrong position and they did a bodge!

Tony

 

[Hugh Jaleak]

The OP has another post regarding that stack, //www.diynot.com/forums/viewtopic.php?p=2017551#2017551 the CI is actually the neighbours pipe, the plastic is the OP's. I suspect looking at the photo's on the other post, the stack may be have been there first, and the wall built around it.

 

[oss]

I,d defo go with the grinder, using heavy gloves ect.I use 1mm thick discs,also would drill out the cement in the collar[carefully]. I don,t know if i,m seeing things but on the photo the existing cast looks cracked.