Durgo/air admittance valves

[Jamesie]

Hi, popping my cherry with my first post!
In the process of putting a new bathroom in my bro's house, space is limited as its only 1700x1800, on removing the very large box section (1sq ft) where the soil pipe is, it became apparant why the box was so big, the soil pipe is massively on the wonk due to a ceiling joist obstructing its true vertical position!
So my plan is to fit a durgo, a) to make the bathroom look a bit bigger, and b) i can get away with prob a 6"x6" box around the soil/durgo.
Could i cut the soil in the loft and support it, and just put a blank on top of the soil pipe where it protrudes through the roof?

Thanks in advance.

 

[Hugh Jaleak]

You could, provided the drains are vented elsewhere on the property. Removing a vent and fitting an AAV may cause problems otherwise if positive pressure in the system cannot escape.

 

[Jamesie]

As far as im aware the house has a common soil pipe, where the kitchen and bathroom are tapped into it, and it exits through the roof to vent. Also to add another spanner! Theres a downstairs toilet which is connected to a saniflo.

 

[Hugh Jaleak]

If there is just the one soil pipe, and the other WC is on a Saniflo I really wouldnt want to be doing anything that could jeopardise the working of the upstairs WC!