Adding toilet to soil stack

[Steve2178]

Hi,

I have an old cast iron pipe that needs replacing and I want to remove it completely and divert an upstairs toilet to the second soil stack I already have a few meters across the wall.

the second soil stack already has a downstairs toilet on it.

I would like to know more as I’ve been informed by a plumber that if I add a second toilet to the top of my other soil stack I could force the water into my downstairs bathroom out of the toilet bowl due to the pressure?
im sure I’ve seen many houses with more than one toilet on a soil stack so can anyone confirm if this is correct or what precautions need to be done to ensure this setup is ok?

here’s a photo so basically I want to put a pvc elbow where the cast iron branch is coming out of my wall and run a horizontal pipe with a slight drop around 3m across to the other soil stack.

I want this pipe completely removing and I plan to remove the hopper and downspout too as I’m extending my conservatory and this wall is going to be an interior tiled wall. I don’t want to have a pipe on my inside wall and or box or in as to waste space.

 

[Aquarius]

I don’t personally see the issue with your proposal. Old Blocks of flats have toilets on each floor sharing a stack, and they don’t have issues.

 

[Steve2178]

I don’t personally see the issue with your proposal. Old Blocks of flats have toilets on each floor sharing a stack, and they don’t have issues.

That was my thought. He mentioned something about pressure building up in pipe and causing downstairs toilet to be effected somehow by it?

 

[Pickwickpick]

That was my thought. He mentioned something about pressure building up in pipe and causing downstairs toilet to be effected somehow by it?

What was he proposing? Or was he claiming it just wasn't possible?

 

[Steve2178]

What was he proposing? Or was he claiming it just wasn't possible?

He said highly recommends I don’t do what I propose and instead just replace the entire cast iron with pvc but that defeats the purpose of me wanting a clear wall to tile

 

[Pickwickpick]

He said highly recommends I don’t do what I propose and instead just replace the entire cast iron with pvc but that defeats the purpose of me wanting a clear wall to tile

Weird, it is really common to have multiple toilets on the same soil stack.

 

[Steve2178]

Weird, it is really common to have multiple toilets on the same soil stack.

so if I go ahead and use a different plumber who said he’d do it no problem he ain’t a cowboy? I won’t have issues with downstairs toilet?

 

[king of pipes]

Can you add some more pictures please ?? of what is connected and internally. Kop

 

[Steve2178]

Can you add some more pictures please ?? of what is connected and internally. Kop

Can’t see the pipe internally as it’s behind a fitted toilet with the cabinet thing at the back. But that’s all it is. Two toilets. One upstairs one downstairs.
Both plumbers I’ve seen havnt even bothered looking inside

 

[Aquarius]

That was my thought. He mentioned something about pressure building up in pipe and causing downstairs toilet to be effected somehow by it?

He might have been trying to say it could pull the trap, but usually happens when there’s a blockage, or if they’re installed in a way against building regulations document H, one example being crossflow connections. I live in a newly built property (2010) and I have 2 toilets connected, albeit on the same level. Just reviewed the photo, does the new stack discharge into a gulley? - this might be the problem.

 

[Pickwickpick]

Sounds like the plumber is concerned about pulling the trap, but even if the new branch is going to be over 6m it can be dealt with by using an internal aav or venting to air so shouldn't be an issue.

@Steve2178 you mention a second plumber, did he also think it was not feasible?
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so if I go ahead and use a different plumber who said he’d do it no problem he ain’t a cowboy? I won’t have issues with downstairs toilet?

WHat length is the branch going to be from the toilet to the pvc soil stack? Also just to confirm, that black pvc soil stack it connected directly to the underground drain and doesn't discharge into a gully?

 

[Steve2178]

Sounds like the plumber is concerned about pulling the trap, but even if the new branch is going to be over 6m it can be dealt with by using an internal aav or venting to air so shouldn't be an issue.

@Steve2178 you mention a second plumber, did he also think it was not feasible?
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WHat length is the branch going to be from the toilet to the pvc soil stack? Also just to confirm, that black pvc soil stack it connected directly to the underground drain and doesn't discharge into a gully?

second plumber didn’t mention an issue at all he said he would do it no issue
The branch would be around 3-3.5m from the stack.

the stack goes into the ground then a clay pipe to an old brick/half clay manhole

 

[Pickwickpick]

second plumber didn’t mention an issue at all he said he would do it no issue
The branch would be around 3-3.5m from the stack.

the stack goes into the ground then a clay pipe to an old brick/half clay manhole

I'd be inclined to agree with 2nd plumber then, you are no where near the limit where there can be an issue with traps.

 

[Steve2178]

I'd be inclined to agree with 2nd plumber then, you are no where near the limit where there can be an issue with traps.

Well both plumbers have not got back to me with a quote yet anyway and it’s been 4 days and I’ve chased them once...

I tried 12 different phone numbers on google 4 days ago and only these 2 answered their phones so gonna have to try and ring around again and hope someone answers

 

[Pickwickpick]

Well both plumbers have not got back to me with a quote yet anyway and it’s been 4 days and I’ve chased them once...

I tried 12 different phone numbers on google 4 days ago and only these 2 answered their phones so gonna have to try and ring around again and hope someone answers

Things have got quite manic work wise, think all the work that was delayed during lockdown is being done at once.

 

[Steve2178]

Things have got quite manic work wise, think all the work that was delayed during lockdown is being done at once.

there’s a crack in the bottom of the cast iron pipe that’s spewing out Rubbish a bit at a time... it’s not too bad but it’s starting to build up so ideally want it sorting as soon as I can.
Based on the description would you be able to tell me the ball park I’d be looking at to do this work?
Cheers

 

[Pickwickpick]

There is so much variation in rates across the country that its really not that feasible for us to give prices on here, also not having actually come out an checked it out there could be various issues that will increase of decrease the difficulty of the job that I'm not aware of. Would say I'd expect it to be in the region of 0.5-1day of labour, but don't forget the big caveat that a plumber quoting in person might be aware of things I'm not.

 

[Steve2178]

Any plumber on here from Middlesbrough? I’m struggling to get anywhere with plumbers on google