Air admittance valve in place of soil pipe

[manatbandq]

I want to remove the upper section of the soil pipe and use an air admittance valve instead, allowing me to remove most of the boxed in section in the corner of the bathroom (nearly 2ft wide but mostly empty space due to the layout of the house).

I'm not so sure, however, what to do with the section of pipe that pokes through the roof. I can get access to cut the pipe in the loft just above the bathroom ceiling but going outside to remove the lead tile and fit new roof tiles is beyond me. Short of paying a roofer is there any other way to make good in the loft, e.g. by just capping off the bottom of the pipe?

MBQ

[Jonathan Pearson]

Unless you want to bodge it, I imagine that you would need a roofer who can replace the tiles - is it really worth all the hastle, to gain an extra bit of space above the AAV?

Jon

[Frank Erskine]

Don't forget that if the soil pipe also serves the handbasin, the AAV has to be above the level of the basin.

[manatbandq]

SWMBO thinks so;-)

MBQ

[Jonathan Pearson]

Ah!! yes forgot about the obvious source of inspiration for the idea Good luck!!!! Jon

[Rob Morley]

Stick a small umbrella up the pipe, open it and secure with baling twine :-)

[zikkimalambo]

Sorry, I know i'm begining to sound like DIMM and his double overhead sump combis, but soil stack vents are a much better idea than AAVs, except where there is no other solution.

Trust one who has been there and got the (smelly) T Shoirt. We lived with raw sewage smells in the house for a couple of weeks (see previous threads via

If you must reduce the width of the boxing (I am sure most SWMBO's would decide they didn't dislike them so much if they had to do all the work!) Then reduce the diameter of the pipe from just above the height of the washbasin, then increase it again in the loft in order to connect to the existing vent.

3" or whatever that is in new money should be fine.

Better still ring the BCO and tell SWMBO that you've spoken to him and that it's not allowed.

[Doctor Drivel]

Sue Hepworth HepVO traps on all upstairs basins, sinsk and baths. No stack on fisrt floor and sorted.

[Doctor Drivel]

A very silly, and illegal, suggestion, when you can get rid of the stack totally.

[manatbandq]

What happens if it isn't?

Currently the toilet waste enters the soil pipe in a junction between the floor and ceiling of the room below. Below that (in a boxed in section in the room below) is a manifold taking the waste from the bath and sink. My plan would place the AAV above the water level in the bath but below the sink.

MBQ

[Dave Plowman (News)]

Who she? Your nurse?

[Frank Erskine]

See

[manatbandq]

It still doesn't answer the question *why* it must be fitted above the "highest flood level" nor what will happen if it isn't. Does the AAV not work correctly if it is fitted too low?

The only reason I can find so far (in another thread in this group) is nothing to do with proper operation but what happens in the case of a blockage. If the the system backs up and the basin is full of water then removing the top of the AAV to investigate the blockage will let the water out of the basin until the water level reaches that of the top of the AAV.

MBQ