Tee into Cast iron soil stack

11 May 2005
Reaction score
United Kingdom
My current bathroom is on the ground floor. The kitchen and sink water discharge into a gulley. The toilet discharges into the drains through the floor. Outside the bathroom is a cast iron soil stack upto roof height which I assume is a vent? I am putting in an ensuite upstairs and have only thought about drains at last minute!!! foolish I know. The soil stack is about 15 feet further along wall from where upstairs toilet will be. I assume I can tee into existing soil vent lower down wall but wondered how you cut into cast iron. everything in wickes I have looked at is plastic. Or is it better to just replace the cast iron with all plastic from the ground up? I assume I can put the bath waste into the same point higher up the stack rather than taking it into a gulley at ground level? All advice is much appreciated.
Sponsored Links
If you're going to start messing about with the soil stack then you would be as well to renew it with plastic. If you dig down a couple of inches at the bottom of the stack you will find the cast iron goes in to a clay socket, remove the cast pipe & use this socket as a starting point for your plastic.
You will have trouble tee-ing in a new bog to an existing cast iron soil stack. Better to rip it out & replace in plastic. Simply tee in to plastic stack using `strap on boss` for your bath. Once stack is in position, mark out where your waste pipe from your bath will be entering stack. Cut out hole for your waste pipe (40mm) & glue boss into position using solvent weld cement. Pop in your waste. Buy a special tee type connection for your bog. Make sure your gradients from your bog/bath to stack are not too steep. For your bog, 9mm for every metre, bath between 18 & 90mm per metre. Max length from bog to stack: 18M. Max length from bath to stack: 3M. Stack should terminate 900mm above your highest window. If you need to connect your bath waste close to your bog connection make sure it is a minimum of 200mm below the centreline of your bog. Personally I never use solvent weld on any of the joints connecting your stack, `cos in the summer it expands a you may have trouble with it if it`s clipped too tightly, blah, blah. If you must use a sealant use silicone, this will move with the plastic. Hope this helps.
Thanks Keego and Traineegas man. Having spent the day looking at soilpipe you have both persuaded me to replace the lot. the idea of cutting the pipe off and using an adaptor didnt seem any easy option. I was loathe to dig up the base of the stack in case it proved a nightmare but it sounds fairly straight forward ( Famous last words! ). Will let you know how it goes.
Sponsored Links
And before you start ask your local planning office if it has a preservation order on it.

Cast iron in some areas has to remain cast iron with some big fines from english heritage etc

Ask first or pay the cost.
Oh, yeah, right Rob, forgot about that one, & make sure you give the Footman, Butler & Maid the day off, before you go pheasant shooting, know what I mean, ;) F**k me DIA, where d`you work???? :eek: :eek: :eek:
traineegasman said:
F**k me DIA, where d`you work???? :eek: :eek: :eek:

External cast iron soil and for that matter rainwater and gutters are protected species in most areas.

If you don't know ask :LOL:
Well in that case you must be far, far away from where I live & work, (mostly deprived areas & inner cities). Rich, smug B*****D! :cry: :cry: I don`t live in a deprived area & may add, I`m just a Bob Geldoff kinda saintly person....
Live or work trainee :cool: :cool:

Is that your gaff DIA, & if so can I come around for dinner?? (Don`t worry, only cost a coupla cheeseburgers & a coke)! Bet that`s your Mam`s. :eek: :eek: :eek:
Not got a mam or papa anymore. :cry:

As I said live or work your guess :confused:
:cry: :cry: so we`re all the friends you`ve got then.... same old story, loadsa money .. no mates.. I`ll be your mate.. if you buy me a house. :LOL: :LOL: :LOL: :LOL:
Thats a lota house dude.

DIA you must be an expert on clay tiles if you've been there a few years.

I'll tell you somefin else too, if the flat roof on that stone mullioned bay window starts leaking your gonna need a good plumber :p
BoooooooooB THE BUILDER!!!! Can `e fix it...... Can `e F**k!!! ..... F***in` Cowboy. :LOL: :LOL:

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Are you a trade or supplier? You can create your listing free at DIYnot Local

Sponsored Links