Soil stack fitting

[marsaday]

I am going to add another toilet in my attic. I am also moving my toilet on the first floor closer to the soil stack.

1) Can i get my soil stack rebuilt before i put in the horizontal connections to each toilet. or is it best to build the soil stack to the first outlet and get that in and then build up again and get the second connection in ?

2) What is the best hole size to core out ? Is 110mm ok ? or should i go for 150mm ?

3) i have at the top of the soil stack a whole piece of cast still. I will need to cut into this to fit my new 2nd toilet. Should i dismantle my soil stack in plastic lower down before i do this so i dont get any bits in the stack (put a lid on it while doing the cutting).

4) Whenb reconnecting up to this cast piece do i use a slip coupling to get the stack into place ?

 

[moliver34]

Your description makes the whole project sound difficult !

Why dont you replace the whole stack, then you can use all the correct fittings. That would include the branch connections to each wc pan soil pipe. That way you would not have to cut into the existing pipe work.