Sharp turn in to inspection chamber advise

[PSC88]

Hi we have part of our drainage design which is currently showing a sharp turn into an inspection chamber followed by a long straight  run of approx 10m

 

i have attached the images below

 

Any thoughts on how this can be over come? Or whether it poses risks of blockage? It’s an upstairs toilet and en-suite bathroom (2 diffeerenr connections in with one connection out

 

 

[Oz07]

Why? That is terrible. Is it so the pipe is joined outside the building? I've had pipes join under a building before probably isn't best practice but when you see something like this it hurts your eyes. In my case the stub stack coming up might have been accessible to rod a blockage thru so maybe thats why was ok. 

 

If you do want it going into that manhole it can be done but just take a long swing into the 90 deg connection of the manhole. You want to be forming a slow bend in connections so the waste is already flowing around. 

[Mr Punter]

That is dreadful.  You need to use the main flow of the chamber for at least one junction.  Use a smaller IC, add 45s to the main inlet and outlet.  Move the chamber down and right.  If you want I can do a sketch.

Edited yesterday at 18:22 by Mr Punter

[PSC88]

Yes it’s exactly to make sure we have the pipe join outside of the building..

 

@Mr Punter any help/sketches would be much appreciated

[Nickfromwales]

If you branch two pipes together underground then they need to be through-roddable, via rodding access at the ends of either one or both, but BCO would prob let you off if you can house inline (above ground) rodding points indoors (boxed in). Failing that, you'd need one at opt 1 or one at opt two, or if the most pedantic BCO then both.

 

If you can add rodding access internally just above TOC internally then no need for either external rodding points.

 

[PSC88]

Thanks @Nickfromwalesthats very helpful, as we have some space to play with it in and around the original manhole is there any way this could work by making the pipe connection external either by moving the manhole further back or to the right 

[Oz07]

16 hours ago, PSC88 said:

Yes it’s exactly to make sure we have the pipe join outside of the building..

 

@Mr Punter any help/sketches would be much appreciated

Just think of the manhole as an inspection access, use the straight through runs and put your bends just before and after connection. You might end up with 4no. 30deg bends on that so 2 before 2 after

Edited 7 hours ago by Oz07

[Oz07]

Just now, Oz07 said:

Just think of the manhole as an inspection access, use the straight through runs and put your bends just before and after connection. You might end up with 3no. 30deg bends on that so 2 before 1 after or vis versa

I would still prefer joint under the building in direction of flow with accessible stub stack and swap your current manhole location for a rodding point. Have you got plenty of fall to play with to give it a nice flow if doing it your original way?

[Nickfromwales]

3 hours ago, PSC88 said:

Thanks @Nickfromwalesthats very helpful, as we have some space to play with it in and around the original manhole is there any way this could work by making the pipe connection external either by moving the manhole further back or to the right 

Having the flow do a 180° u-turn is pretty naff, so I’d not do as your drawing suggests as it’ll always be a (very) weak point.

 

If you install one of those access pipes immediately above ground internally, you can Y branch underground and you need ZERO other pipes / manholes / rodding points whatsoever. Simpler and cheaper, and bombproof. 

[PSC88]

Hi nick

 

i think I would (ideally) want to avoid an access pipe internally as it’s a large open expanse hallway area where this pipe passes through.

 

if we were to join as you sketched with a Y connection under the building but added two rodding access points as per your sketch opt 1 and opt 2 this should mean its rodable both ends 

 

[Nickfromwales]

8 minutes ago, PSC88 said:

Hi nick

 

i think I would (ideally) want to avoid an access pipe internally as it’s a large open expanse hallway area where this pipe passes through.

 

if we were to join as you sketched with a Y connection under the building but added two rodding access points as per your sketch opt 1 and opt 2 this should mean its rodable both ends 

 

Yup. 👌

[Mr Punter]

Here you go @PSC88.