Soil pipe for ensuite bathroom (air admittance valve)

[carlsbergy]

Hi,

I am installing an ensuite bathroom approx 8m away from the external soil pipe running down the outside of the house, which will then connect into this soil pipe. I have enough run on the pipe from the proposed toilet/shower. Should I install a one way 100mm air admittance valve where the pipe comes into this ensuite?

Thanks

 

[Bodd]

If I'm reading this rightly no I don't think you will need to.

Bod

 

[Richard C]

The maximum unvented branch length for a w/c is 6m so at 8m, you need to vent the far end with a mini stack & AAAV, assuming you have another open vent on the drain; without one you will have siphoning problems. You should read the BR’s Part H;
http://www.planningportal.gov.uk/uploads/br/BR_PDF_ADH_2002.pdf

Also be aware that what your doing must comply with several other BR’s & is notifyable work.

 

[carlsbergy]

Thanks Richard, much appreciated