Do i need a Air admittance valve / durgo

[nyck]

After about 5 years im finally getting round to turning my old bathroom into an en-suite .
All the Soil pipes were replaced when i had my extension built and bought a Durgo thinking i needed one ?? I'm in the process of installing the back to wall WC,sink and units etc and it would make my life a lot easier if i could do away with not fitting the 100mm durgo valve .
As you can see in my basic diagram i've already got a SVP going through my roof in my system

thanks

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• nyck
• 29 Sep 2013
• 1

 

[Hugh Jaleak]

I would think you'd need the AAV. On a soil run of that distance there's a good chance you'll have problems without one IMO.

 

[nyck]

I would think you'd need the AAV. On a soil run of that distance there's a good chance you'll have problems without one IMO.

Could i get away with a mini Air admittance valve ,ie like the one below as this would be a lot easer for me to fit ,i could fit 2 or 3 if necessary ??

http://www.screwfix.com/p/floplast-air-admittance-valve-32-x-40-x-50mm/42968

thanks

 

[Hugh Jaleak]

Dont see why not, just need some means of ventilating the pipework to prevent siphonage as the WC can fill the pipe when discharged, causing a partial vacuum behind it.