Blocking off redundant drains

[Tipper]

I am currently renovating a house and in changing the bathrooms and kitchen I want to block off two redundant drains that are no longer required.

In the kitchen there is a gulley in the middle of the kitchen floor, 100mm, (think of Granny's scullery!) that is no longer needed and in the bathroom there is a 100mm drain connection in the floor that runs through a back inlet gully outside and then to the main drains.

What is the accepted method of blocking these off?

Can I just fill them with concrete or similar or should they be dug up, it's a bungalow with solid floors, and blanked off at the inspection chamber outside?

 

[dann09]

Typically,redundant drainage can be filled with a plug of semi-dry concrete mix at inlet and outlet.
If BCO is involved then you may have to dig the redundant drainage out.

Outlets can, typically, clearly be seen connecting to a main soil drain, usually in a manhole.

The gulley connection might require replacement of the gulley. Any pics?

Before any work you must be certain that you have the correct outlets.

 

[luisdesign]

If you are backfilling you really need to make sure that you appropriately blank off the end and pump concrete steadily to ensure a true plug and to avoid it spilling out and blocking waste connections that you need.

This includes checking that no other connections are concealed and use the same pipe to get to the manhole. A quick way is to run all other water sources and see if anything dribbles out at the end.
This isnt necessarily indicative that there are NO connections, just no active ones... theres nothing to say there is not another redundant connection somewhere...

Finally, I would have thought it is best to fill the pipe completely, to omit any chance of a pipe collapsing?

 

[dann09]

Why would a drainage pipe collapse once its no longer active? It's been empty, so to speak, for the majority of it's working life?

What costs would be involved in pumping to the rear or a property, perhaps over a roof, to fill a, typically, short length of pipe? Not to mention a pumped mix is the wrong mix.