Connection to existing sewer junction

[Olf]

As it happens the extension will be sitting above a sewer (public, we and the neighbour), with the junction right next to - and right where the new sink & dishwasher want to empty to:

 

Can I simply run a pipe with (nearly) 90 deg bend at the end (inside the manhole) so it discharges into the end of our sewer run? Or even the straight (technically public) run? Or will I have to dig a separate junction?

Here is the real detail:

 

I admit that I'm partially inspired by the rainwater pipe sneaked into the manhole

 

Edited February 4, 2021 by Olf

[Mr Punter]

Your pipe will need to come in at the same level as the other side branch.  You cannot connect higher up the side of the chamber.

[Mr Punter]

Do you have consent to build over the sewer?

[Mr Punter]

I think your "rainwater pipe" could be gas ducting!

[Olf]

3 hours ago, Mr Punter said:

Your pipe will need to come in at the same level as the other side branch

 

The level is not a problem. But it creates a new issue: do I have to replace the last stretch of my sewer with a 90 degree junction ('square junction') to accomodate the new pipe? If yes, would it have to be open (meaning enlarged/new manhole) or could I get away with something like

And how do I marry up existing clay with modern plastic pipes?

 

3 hours ago, Mr Punter said:

Do you have consent to build over the sewer?

Application lodged, money taken, waiting for any response.

But thank you for pointing this out!

Considering all the changes/new connection (like this) are to be done on my 'private' branch, I did not mention such ideas during application.

 

3 hours ago, Mr Punter said:

I think your "rainwater pipe" could be gas ducting!

Well it is a proper cowboy stuff, isn't it? But no, the other end can be seen under carport gutter.

Funny enough, the carport is in a depression so it gets flooded with every rain anyway- but sorting this out will be for another topic

 

[Mr Punter]

I am not sure where the manhole is in relation to your proposed new connection but if you can get to the right invert level and are not in completely the opposite direction to the run you should be able to use a slipper bend to the manhole and redo the benching.  If you don't know what you are doing, it may be easier to just get a price from someone who does.  I would not do this job myself but I sort of know how i it should look.

[Temp]

In this photo you have a branch coming in at the bottom joining the main run which is flowing left to right. Ideally you would cut the concrete, bash a hole in the brickwork and form a new branch like the existing one. This would either come in from the top or one side of the existing branch. Then you repair the concrete (called benching). The new branch can be in plastic pipe.

 

 

Here is one before the benching has been replaced..

 

 

Source: https://www.pavingexpert.com/drain05#exic

 

Ideally the new would be at the same level as the existing branch but if your new pipe will only handle water not "solids" it should be fine to have a step entry as per this photo.

 

You can have more than one branch on the same side if there is room. 

 

[Olf]

@Temp  - the photo you attached is what I need - many thanks!

The benching and manhole wall repair is little in comparison with building a whole new manhole.

I'll let it the groundworks folks to sort out, but I need to know the right way, rather than let them running loose with some botched idea that makes their life easy, and mine hard afterwards.