soil stack.
 

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.

soil stack.
 

soil stack.
 

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.

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.

soil stack.
 

soil stack.
 

soil stack.
 

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?

Sorry, I may have misled a little. The smaller pipe is not a soil stack as 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.

soil stack.
 

Owain wrote:
Lobster wrote:
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?

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.


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.

Owain