Stench Pipe conflicting info

[garash]

Hi, Having made a few enquiries on having a new Bathroom I have been told by one Guy that the boxed in Stench pipe which is full length next to the Toilet and goes out of roof, must stay. However during another visit/quotation the guy said it that although it cannot be totally removed it could be reduced in size meaning that instead of looking at an 8ft pillar running up the wall I would end up with a plinth of about 4ft high. He did explain what the pipe was called but I cannot remember except to say it included the word 'Air'. Can anyone confirm if he is correct as I am baffled as to where the 'fumes' will go. Thanks

 

[Nozzle]

Air Admittance Valve / Durgo

Nozzle

 

[denso13]

AAV's work but keeping the vented stack is the best option.

 

[bernardgreen]

An air admittance valve allows air to enter the sewer pipes to prevent suction pulling water out of U bends.

A vent allows sewer gas to vent to the open air. If the stench pipe through the roof to open air is the only vent to open air then it cannot be replaced by an air admittance valve

 

[HERTS P&D]

Go with the first guy.

Andy

 

[denso13]

If the stench pipe through the roof to open air is the only vent to open air then it cannot be replaced by an air admittance valve

Not strictly true.

https://floplast.co.uk/wp-content/uploads/2018/05/AAV-Performance-Installation-Guide.pdf

 

[bernardgreen]

From that document

7.3 A pressure increase sufficient to raise the level in the water seal or to cause foul air to bubble up through the seal is an indication that a drain blockage has occured or that the system is being overloaded or otherwise misused.

A toilet pan bubbling with foul smelling gas can be a useful early warning sign of a problem that has to be resolved and this early warning would not happen if the soil stack was vented. But it can happen for reasons that are transient ( overloaded for a short period of time ).

 

[Hugh Jaleak]

The head of the drainage system should always be vented. I'd never advise removing an open vent and replacing with an AAV, it is just inviting trouble. (Then there is then also the issue of making good the hole in the roof left after removing the vent pipe!) The vent is there for a reason, let it do its job.