Internal Durgo

[Richely]

I am adding ensuite and building inspector has asked for durgo valve to be fitted internally to toilet soil pipe as length of run is around 5m. The toilet sits against wall and pipe directly exits the back of house and then runs 5m horizontally across to soil stack. What is best way to connect the pipework for the durgo? is there some sort of connector which attachs to the internal part of the soil pipe behind toilet and then branch horizontally to an upright section? There will also be a sink draining into top of soil pipe so is getting a bit crowded behind toilet.

 

[Mr Chibs]

Is it feasible to add a vertical section of pipe AAV on top, somewhere along the 5m run?

A sketch might help, bit confusing, as you say the pipe exits the back of the loo and goes outside?? can't you put a branch in and outside and fit an AAV there?

AAV needs to be higher than sink waste.

 

[Richely]

Thanks for your reply, the toilet backs onto the wall and the soil pipe exits out the back through the wall and then runs for about 5m along the external side to the soil pipe. I guess I could move the toilet location rather than trying to pack it all in behind...the building inspector seemed to want it inside the ensuite but maybe I should check if could go outside

 

[Nige F]

See if you can go outside with an open vent - OK you'll have 2 then but O.V is better than a mechanical inlet only vent . Can you post a pic. of outside ?

 

[Richely]

Hi, these are some pics of inside and out, pipe coming in is next to toilet
Thanks

 

[Mr Chibs]

I'm no expert regarding AAV's but from the photo's you've just posted, I'd like to know why you need one?
I would have thought the open stack sufficient. Perhaps one of the drainage guys can explain.

You might want to get the pipework sorted/lowered (at extension end), as the fall doesn't look smooth.

 

[Richely]

No, it's a bit of a dog leg there, I thought inspector would ask for it to be changed but seemed okay with it...the valve was apparantly because the run looked quite long, its about 4.5m and so he thought durgo should be put in...it messes up my internal layout a bit though

 

[Hugh Jaleak]

Inspector may seem ok with it, he's not the one who's got to unblock it. It does look too horizontal at the top end, I would strongly advise you adjust it to achieve a constant, steady fall along the entire length of the horizontal run, that to me would be more critical than an AAV. Leave it as is, and I think you'll be finding it's blocked very quickly....

If BCO still insists on an AAV at the top end, change the bend for a junction to take the WC, then fit the bend in the unused socket on the junction, pointing upwards, a short run of pipe to get above the basin height and external grade AAV on the end of that.

I'd also be concerned about the length of the waste run, that may well exceed permitted length, and may need upsizing, or at the very least Anti Vac traps, to prevent them being pulled.

 

[Richely]

There is a fall on it but not really obvious from picture, I agree though it's not great. Using a junction might work, prob a daft question but would some waste flow into that part of the pipe and become trapped or would the junction be reversed to help prevent that?

 

[Hugh Jaleak]

Junction should be fitted in direction of flow, so the water should carry everything round the bend and downstream, especially if it's got a sensible fall on it. If the bend is fitted into the spare socket the section of pipework where anything could accumulate upstream is virtually nil anyway.