Can i remove an unused soil stack?

[markelane]

Hi,

I have a victorian house with the bathroom downstairs.

The bathroom was obviously upstairs at one point in time because there is a soil stack to the first floor, continuing to vent above the roofline. There is no longer anything connected to the stack but I appreciate that it is continuing to act as a vent to the foul system.

My question is : will it be OK to remove this stack and cap it underground? (It's right in the middle of where I want to put a doorway). I notice that my neighbour (semi detached) does not have a soil stack, so I wonder whether my vent is acting for both properties?

I look forward to any advice.
Cheers
Mark

[danensis]

You need some sort of vent at the top of the pipe run, otherwise water will get siphoned out of the downstairs toilet. It could just be a low profile air-inlet valve adjacent to the downstairs toilet. Unfortunately as far as I know (and Tony or Flowjoe may correct me here) they are only available for indoor use.

[markelane]

Wow - a quick reply!

Cheers for that. I've been reading about these Air Admittance Valves.

Out of interest - what would cause the siphoning of the water from the toilet? (there is no toilet upstairs) - would the bath/sink/washing machine etc waste cause this to happen? Or perhaps the neighbours toilet?

Cheers for any advice
Mark

[danensis]

Usually a toilet - it needs a body of water large enough to fill the pipe so that no air can move upwards as the bolus moves down.