AAD valves for toilet

[trevorbayliss]

I need a bit of advice on using an AAD on a new bathroom.

Build control has been out today to check all my latest works and part of that was my new soil pipe run and waste runs. All was ok.

However he told me i might want to consider an AAD near to my toilet because the run is quite long. It is going into an external stack which is vented, but because of the length he said i might get an issue. He isnt making me fit one though. However it isnt an issue to fit one, so i will probably do it. I am just not sure where i should put it.

First the soil pipe has a good fall. It drops 13cm before it gets to the outside wall. The length is 3.6m approx. Outside it turns 90 degrees and goes into the stack which is another run of 3.6m approx. Again the fall is similar or greater than 13cm.

Ideally i will fit my sub stack with AAD just after the toilet pan connector. IS this ok ? It means i can keep the AAD inside the cupboard for the immersion which is on the other side of the wall from the toilet.

The photo shows my square hole ready for the soil pipe to fit through. The ply lined section of walling will be for my cupboard and immersion. I would put a Tee just the other side of this wall and then have a 1m section rising upwards with the AAD in the top. I will prob need to also fit an angle as the soil pipe is at an angle, so the 1m vertical stack will be leaning over.

 

[Nige F]

sounds good to me = you might find an underground (orange) bend of a fine angle to get your 1 m. pipe upright. That's OK because the orange pipe/fittings can't be used outside exposed to UV light. Won't be much in your cupboard

 

[Hugh Jaleak]

Going to be pedantic but it's an AAV, Air Admittance Valve. Wouldn't be a bad idea to fit on on that length of run, will guarantee the WC trap doesn't get pulled. Ventilation of the drainage system is already provided elsewhere.