How to decommission unused manhole channel?

[jazzbhatia]

Hi All,

I have started digging the footings for my extension and have encountered an issue with the plans for the drainage.

Currently the gully that serves the bathroom (tub, sink) and the kitchen sink has its own channel into my neighbours manhole.

My cast iron soil stack (which I plan to replace with plastic) also has its own channel into my neighbour’s manhole.

My plan is when replacing the soil stack I will do the following:

Route the first floor bath tub, wash hand basin and WC into the soil stack
Route the new ground floor WC and wash hand basin into the soil stack
Route the new external kitchen gully into the stack

Once this has been done it will leave the old gully channel not connected to anything.

My question is how to I decommission this channel so that there is not a back flow into the soil/new foundation area.

The manhole is constructed of brick and the channels appear to be of clay

If there is a part/cap that I can use what is it called

Thanks in advance

 

[noseall]

We would plug it with concrete and trowel it smooth to suit the benching.

 

[jazzbhatia]

Hi.
What mix do you recommend and how far do you plug?

 

[noseall]

Some rich fatty concrete, i.e. five parts ballast to one part cement with an extra scoop of sharp sand for that added fat.