fitting extra soil pipe into existing stack

[alecson]

Is there a 'slip joint' available to allow me to cut out a section of my stack and let me fit an extra soil pipe without having to take the whole stack down ?
Also how close can any fitting be to ground level (I've checked my manhole and I've worked out that the level of my bend is about 800mm below ground level)

 

[Biggles..]

slip sockets are available for such works.

there is a minimum vertical length before the bend of which at this late hour i cant for the life of me remember

 

[Richard C]

there is a minimum vertical length before the bend of which at this late hour i cant for the life of me remember

450mm to the invert for a vented stack but increased if the property is over 3 storeys.