Alternative to external gully drain

[Wagas]

On my first build the plumber connected the kitchen sink and dishwasher wastes through to the outside wall and then had pipes going to a gully drain. I didn't know any better so just went with the flow but having pipes on the outside wall isn't attractive. On my next build I don't want to have this system so do I just put a drainage pipe through the block and beam floor under the kitchen sink and can a plumber then do something straightforward to connect the wastes to it without the need for a gully drain?

[Conor]

Yes- standard practice now is to have a 110mm waste pipe come in to the house and up through the slab. Your sink etc will drain in to these within the cupboard- usually with something like a rubber reducing thingy. You have nothing above ground. It's part of building regs here in NI, not sure about elsewhere.

[Temp]

+1

 

That's what we did. 

 

PS: Our 80mm rainwater down pipes also go into 110mm via rubber adaptors.

Edited May 25, 2020 by Temp

[dpmiller]

do it with a back entry gully and it's then rodable and you've somewhere for your outside tap to leak into as well...

[Wagas]

Do I need to bother with a back entry gully at all on the house? There will be an inspection chamber not far away for rodding. I thought these days there's under sink traps to stop smells etc and obviously the toilet takes care of itself 

[Mr Punter]

2 hours ago, Wagas said:

Do I need to bother with a back entry gully at all on the house? There will be an inspection chamber not far away for rodding. I thought these days there's under sink traps to stop smells etc and obviously the toilet takes care of itself 

 

You can have an access point for rodding at the base of the stack.  All the internal stuff will have a water trap to stop sewer smells.

[Wagas]

Ok, thanks. Last question... Do I just need one stack under the sink for kitchen sink and dishwasher or should they have their own stack?

[PeterW]

Both into one, and dishwasher before sink where possible so it washes the sink waste through. 

[Big Jimbo]

The only other thing i would add, is if you are having a waste disposal unit in say a sink and a half. I always run the waste disposal on it's own 40mm waste until it get to the 110mm. The reason for this, is that having fitted hundreds of kitchens over the years, if something is going to block, it will be the waste disposal, due to not having enough water run through them. While you are waiting to sort out the blocked waste, you can atleast continue to use the sink.