Remove soil stack vent and add AAV

[Slider_0809]

Hi,

Hope someone could advise on the below please, sorry admin not sure if this should be under the plumbing or building regs forum.

Currently doing our small en-suite and would like to create more space by removing the soil stack vent (where the blue line is) and adding an AAV. This soil stack just services this one en-suite and there is obviously nothing else above this point. The family bathroom on the opposite side of the house has it's own stack and vents outside. The AAV will be accessible as we intend to create a false wall under the window to house a concealed toilet cistern and add an oak shelf on the top which will can be removed to access the cistern and AAV.

Is this feasible?

Thank you

Garry

 

[Slider_0809]

Example below of what we're hoping to achieve.

Thank you

 

[denso13]

Yes, no problem.

 

[Slider_0809]

Thanks for the reply.

 

[dilalio]

Sometimes you need an SVP both sides of a house.
Case in point, just added a downstream vent to a big house near me.
The higher up bathroom on opposite side had a vent upstream of it but was still having issues pushing air out downstream.

 

[Wayners]

AAV are good but can play up so access is important but yeah. Crack on.
I have one

 

[Hugh Jaleak]

Speaking from nearly 40 years experience with Drains. It might be ok, but Vents are usually put in for a reason. Where does this Stack join the underground system? If it's at the head of the run, then really needs venting, if it connects in along the run, and there is a Vent upstream, then less likely to be an issue.

Can also depend as to how well the drains were laid as to whether there will be an issue!

 

[Slider_0809]

AAV are good but can play up so access is important but yeah. Crack on.
I have one

Any recommendations for a good quality one?
I was going to purchase this one…

https://www.screwfix.com/p/mcalpine-push-fit-air-admittance-valve-black-110mm/236hp?ref=SFAppShare

 

[denso13]

Mcalpine are decent, looks good.

 

[Slider_0809]

Speaking from nearly 40 years experience with Drains. It might be ok, but Vents are usually put in for a reason. Where does this Stack join the underground system? If it's at the head of the run, then really needs venting, if it connects in along the run, and there is a Vent upstream, then less likely to be an issue.

Can also depend as to how well the drains were laid as to whether there will be an issue!

I’m assuming this connects to the main house drain along the run. I say this as I assume the drains run down the street and the rear of the house where the stack for the main bathroom is higher than the front. The rear main bathroom has its own stack which is externally vented.

I intend to also add an anti syphon trap to the basin in this bathroom too.

 

[dilalio]

I’m assuming this connects to the main house drain along the run. I say this as I assume the drains run down the street and the rear of the house where the stack for the main bathroom is higher than the front. The rear main bathroom has its own stack which is externally vented.

I intend to also add an anti syphon trap to the basin in this bathroom too.

Odds on it will be fine, but if it isn't you'll know why

Perhaps a trial run before everything gets finished and made good.

 

[Hugh Jaleak]

I’m assuming this connects to the main house drain along the run. I say this as I assume the drains run down the street and the rear of the house where the stack for the main bathroom is higher than the front. The rear main bathroom has its own stack which is externally vented.

I intend to also add an anti syphon trap to the basin in this bathroom too.

Can only try, bear in mind an Anti vac Trap will do the same as an AAV, it will let air in behind the water but wont let positive pressure out. This is often where the issues start, the drainage system creates positive pressure for some reason, it can no longer escape out the Vent so looks for another way out, usually through a Basin, Bath or Shower trap.....