Air admittance valve (AAV)

[coeur]

Hi, my house has 3 soils stack pipes, one for each toilet. One, for the downstairs toilet, is boxed-in so I assume it has an AAV fitted. The other 2 soil pipes vent in to the loft space. We are experiencing some smell issues and hope that AAV's will solve the problem. My questions is, can I fit AAV's to both soil stacks in the loft or does one need to vent direct to air?
Thanks

 

[Nige F]

At least one in the loft needs to vent through the roof, I would do both of them

 

[S_cambo]

Is it possible the smell maybe coming from a wash basin trap in the downstairs loo? I had an issue in my aunts house that sounds similar and a anti vac trap sorted hers.

***edit: i read you're post wrong sorry. Thought the issue was in downstairs loo

 

[coeur]

Are you saying that fitting an AAV to each stack wouldn't work or is there a regulation that states one must vent through the roof? Just trying to understand the background to your answer.

 

[coeur]

Is it possible the smell maybe coming from a wash basin trap in the downstairs loo? I had an issue in my aunts house that sounds similar and a anti vac trap sorted hers.

***edit: i read you're post wrong sorry. Thought the issue was in downstairs loo

No problem. Smell is definitely from the loft.

 

[Hugh Jaleak]

Building Regs state the highest point of the drainage system should be vented to atmosphere. You will need to break through the roof to terminate one outside, so if it's possible, I would common both pipes into the one vent. AAV's on existing open stacks can cause more problems than they fix.

 

[HERTS P&D]

Check your manholes for a blockage.

Andy

 

[dilalio]

Check your loft for a dead animal(s)