i am looking at fitting an en suite wc in an upstairs bedroom and my vertical soil pipe is a real pig to get at , even using a slip fitting i dont think i can tap into it . I can however easily tap into a horizontal run that comes from another wc downstairs, it would go something like , original wc , into- 92.5 bend , almost straight into a swept T ( connecting to new soil run ) then around 30cm later straight into the soil stack .
Would i get problems with waste coming into the lower downstairs wc that i am tapping into ?
Would i get problems with waste coming into the lower downstairs wc that i am tapping into ?