Ground floor loo with no stack + kitchen sink waste = HOW?

[goosebump]

Im trying to get kitchen waste water out of the house, avoiding the need to dig up the concrete slab. Im hoping to be able to use the soil pipe in the downstairs loo - its old school clay soil pipe set into concrete floor.

Having plumbed in a new loo, Plan A is a partial success - waste water from the kitchen sink to a boss on the pan connector (Ive had to reduce the 40mm pipe where it enters the boss). However, its really gurgley/siphoning which is not good. Is it worth fitting an AAV somewhere, or should I just give up and start smashing slab?

Is it at all permissable to fit a mini-stack with an AAV on the top inside the downstairs loo?

 

[Nige F]

it is permissible - due to the laws of common sense - just don`t let the building police know you`ll still need a mini aav on the end of the run under the sink

 

[goosebump]

Thanks Nige F. Im learning as a I go and dont trust my judgement.
Do you think its best to fit a mini stack? Or is there no need if an AAV under the sink stops the siphoning?

 

[Hugh Jaleak]

I'd bite the bullet and fit a stub stack. The restriction where the 40 reduces to 32mm could come back to haunt you if it blocks..... Depending on layout of W.C. you may not need to break the floor, McAlpine do a coupler that will fit into the 4" salt glaze, and take you to 110mm plastic, and includes a 40mm boss. (McAlpine DC1-BL-BO). AAV on top of stub stack needs to be above spillover level of highest appliance. (Probably the sink in your case.)

 

[goosebump]

Thanks Hugh Jaleak - the reduction is something Im not 100% convinced by either. However, its easily accessible and given the amount of other work we have on, I think it might be ok as a temporary measure.
And you are right about the clay pipe - I was careful when removing the old loo, with the result that the top of the glazed pipe still has its "collar" (scuse my ignorance of the right terms) intact, poking above the floor. Many thanks for the advice on McAlpine plumbing parts, half the battle with plumbage seems to be knowing what parts are out there!

 

[Hugh Jaleak]

Collar is one of the names used! (Socket is also used.) Plumbage is a new one on me though! (Try 'Plumbing instead'. )

The reduction should be ok short term, but sink wastes do have to handle a lot of 'gunge' and as a result you may find the 'gurgling' gets worse. Worth noting that if you are connecting a washing machine, that will require a 40mm waste. They pump out the water at a fair rate of knots, 32mm may not handle the flow which can lead to problems.....

The McAlpine part is similar to a pan connector, the finned end should fit inside the clayware pipe, from that you can carry on in 110mm plastic to connect W.C. etc.