Bottle trap to main sewer run connection

[Annker]

As part of my renovation work I am installing a new 110mm sewer run with various connections to an existing manhole.

The most upstream connections (2x WCs) have been made and now the run routes down a side entrance to meet the existing manhole.

 

Being a side entrance the width of ground I have to lay pipework in is limited to ~800mm, however along this section of the run I have to pick up a RWP and the usual domestic wastes (DW, washing machine and kitchen sink) The current plan is to use bottle traps to connect these various wastes onto the main sewer run. (Edit to add the current system is combined and BC have ok'ed combining all wastes)

 

The narrow width combined with a relatively deep invert level (~700mm), means I think the bottle traps branches would have to be laid inclined at a 45 degree angle downwards (certainly in the vertical plane and possibly in the horizontal plane) so they can connect to the top of the main sewer run; as opposed to a side entry connection 

 

I'm unsure if that top entry connect is typically done or if it could be a problem, hence I'd appreciate any comments or advice on my plans. TIA

 

Sketch below to help illustrate how the connection may be made:

 

 

   

Edited September 9 by Annker
additional info

[saveasteading]

I think top entry is OK. I would be browsing through the regulations though. Building Regulations Document H.

As you say, angling in the direction of flow would be good. It will reduce turbulence, hence aid flow. It also provides a little more flexibility for fixing.

[Annker]

2 minutes ago, saveasteading said:

I think top entry is OK. I would be browsing through the regulations though. Building Regulations Document H.

As you say, angling in the direction of flow would be good. It will reduce turbulence, hence aid flow. It also provides a little more flexibility for fixing.

I will have a browse through AD H, I'll be running my plans, once firmed up, pass my BCO as well.

 

My reasoning for angled the branch in both planes was purely if needed to make the connection given the narrow spacing I have to work within but as you rightly point out it probably would be beneficial in terms of aiding flow regardless.