Internal Backdrop for connection to existing sewer manhole for thames water

[tokyotecubate]

Hello! 

 

We just obtained consent for a sewer connection to an existing thames water sewer manhole. The existing sewer pipe level is more than a meter deep in the manhole, where our sewer pipe does not reach that deep in following the 1:40 flow ( it will be at most 40cm deep by the time it reaches the manhole. 

 

Having consulted most plumbers, the normal way to do it is to do an internal backdrop to bring the pipe to the 1m level of the main sewer pipe, however I read on the guideline from thames water that they do not recommend so - I wonder if anyone here has done a direct connection to a manhole, and whether we really do need to put the backdrop ouutside the chamber? Doing so would entail a LOT more work from the plumber ( and from what I saw, quite unneccessary work as well, as the manhole chamber is Huge and the internal backdrop would not restrict access at all)

 

Keen to know your thoughts, and generally from your experience with thames water about this. Thank you! 

[Mr Punter]

You can run your pipe as steep as you want.  1m depth really is pretty shallow.  Ask Thames Water, but a 1m trench is not the end of the world.

[Russell griffiths]

As above, run at a little bit steeper fall, then slope down to meet the manhole invert for the last 4-5m. 
you can run plastic steep, it won’t leave your no 2’s stranded. 

[Nickfromwales]