The Brew Cabin

Following the installation of roof lights in my attic, I've noticed that the waste drain vent pipe is emitting not too pleasant odours if the wind is in the wrong direction!

Question - What to do?

Cutting external vent pipe in attic and use of an air admittance valve - a possibliity, but matter is complicated due to use of septic tank. I understand that this would be OK only if septic tank was seperately vented?

Extending exiting pipe to roof apex level - a tad unsightly and one I would want to avoid if possible.

Any other solutions/products I've missed?

Any ideas welcome

Is this an internal SVP? It could be diverted outside and elevated to a position where any odours are not likely to find their way back into the house.

An AAV is possible, but it depends on the system layout and can be more trouble than they are worth unless they're properly fitted.

Proper external venting away from any windows and at a sensible height is the favoured solution.

SVP connects to WC drain and goes up internal wall through slates. Main trouble is that the side of the house that SVP is on is the one where the prevailing wind comes from. So problem mainly when slight breeze is blowing as opposed to the higher speed winds of Oct-Mar.

AAV could v well be problematical as you say. Not sure I actually want a vent on septic tank inlet drain in the garden.

Easiest solution may be to install 2nd SVP on windward side of house where we have another bathroom, positioning it away from windows at adequate height.

A relative suggested that it might be possible to vent a sink, which could cut down on odours. No idea if this idea is a goer??

How is the malodorous whiff finding its way into the house? Would elevating the height of the SVP help eliminate the problem or could a bit of swan-necking deliver the odours to a point further away from any windows?

i have similar problem, but have agreed with BCO that i can swan neck it so that it goes up the inside of the roof space to the ridge and then put a ridge vent in.

That sounds like a sensible solution - would it be possible on your job, Jim?