soil stack.

[deckertim]

My main sewer pipe is under the path at the side of my house and then exits out through my neighbours property. The main soil stack is vented at the top, but I also have another vent stack that is near to where the sewer goes into next door's property. Unfortunately this second soil stack is attached to the single story kitchen. As a result it is about 6 foot high and whenever I go around the side of my house I get a whiff of it.

As far as I can ascertain this is all original and the house was built in 1904. Is there any reason for this short vent stack. Could I block it off?

I am aware that maintenance of the sewer is the responsibility of the water board because of the age of the house and because it is shared with a neighbour. Could blocking this off cause a problem with them? I expect they will do anything in their powers to avoid working on this, should it ever go wrong.

Thanks

Tim.

[The Natural Philosopher]

If the main vent is near enough, you could get by with an air admittance valve on the short stack - or a shortened version of it. That will stop the pong allright.

Make sure however that you have rodding points nearby..

[dom]

Maybe. The forward air pressure from flushing the upstairs loo may be sufficient to "blow through" a trap elsewhere - e.g. kitchen sink. That may be why the second vent was put in.

[Lobster]

What is the secondary soil stack for; does it just have waste connections from the kitchen (ie no toilet?) Could any such pipes be run into a suitable surface gully outside the kitchen?

I'm wondering whether a Durgo valve could simply be plonked on the top of this stack, which would permit air entry to avoid formation of a vacuum within the stack, but not let the pooey smells out. Can't see why that wouldn't work assuming the stack is venting the same pipe as your main stack (which would be adequate to let gases escape); my only concern would be whether you can use one outside - AFAK they are intended for indoor use for obvious reasons.

Alternatively, wouldn't simply extending the existing stack upwards a bit to a regulation height be the easiest solution? or is there scope for extending the stack horizontally(ish) (ie sloped up a bit) towards the main house, then extending upwards attached to the house wall?

David

[The Natural Philosopher]

Agreed.

A lot depends on what is downstream..if the neighbour has a stack...

The general principle is that air valves work upstream of at least one free vent.

In my case I have tow fairly long branches one of which is stacked and the other is valved. The upstairs toilet has not yet blown the traps on the downstairs stuff on the same branch.

[Owain]

I don't think having a ventilating portion of the stack sloping, or changing to smaller pipe, is allowed by B Regs, but it does seem to me to be the most elegant solution.

Owain

[deckertim]

such, it is just a vent pipe connected to an access chamber, where the main sewer from the toilet and bathroom meet the connection from the kitchen drainage. The only other thing going into this are the rain water drains for that side of the house.

I must admit this is an education, I never knew the purpose of the venting in sewage systems.

[The Natural Philosopher]

Certainly is allowed. I go from 4" to 3" and run 15 meters horizontal on mine..

Its sole function is to keep the drains at atmospheric pressure.

However beware long horizontal runs: bathwater will condense and drip out of the end.

Fixed in my case by giving it an upwards slant of just a few degrees.