replace 68mm with 110mm?

[cdel2005]

Hi everyone

Customer wants the downpipe and hopper replaced with soil pipe
can i cut downpipe just above ground an use a 68mm to 110mm converter
or should I dig down and replace gully with underground sweeping bend and connect to clay with adapter

not to sure with building control on this one.
1 pipe system

cheers

 

[Ric2013]

Current installation is via a back inlet gully, I take it?

I'm pretty sure reducing from 110 to 68 at low level will result in increased risk of blockages at that point, so, from that point of view, I think it would not strictly comply with the requirement to minimise the risk of blockage, though if there's a rodding eye just above the reduction, that might be good enough.

Any work on underground drains is notifiable work as far as Building Control is concerned, so get your money's worth and ask them the questions. In my experience, they are generally delighted when people ask questions rather than just go ahead and do it wrong (and I've even known them say 'technically that's notifiable, but we aren't really interested if all you are doing is x').

I take it what you mean by '1 pipe system' is you have is a combined drainage system? In which case, no you can't remove the gully as you need to separate the smelly foul sewer from the rainwater pipe, which is surface water: that's why the gully was put there in the first place.

But I have to ask: why? Does the customer like the look of soil pipe, or are you working on Buckingham Palace?