Shower trap strange goings-on

[denso13]

IF venting this with no AAV fixes the issue, would it be suitable to use a 4" flexi air ventilation type tube to get from the top of the stack to the vent? Either the metal or pvc ones?

Should really be soil pipe/fittings, not vent tubing.

 

[dilalio]

IF venting this with no AAV fixes the issue, would it be suitable to use a 4" flexi air ventilation type tube to get from the top of the stack to the vent? Either the metal or pvc ones?

Try it first and see what happens.
Only issue would be condensation if the flexi is fully supported, it should run back into the stack and not be an issue.

All depends on results from leaving it as a svp.

 

[Hugh Jaleak]

I'd run 110mm soil pipe from the existing termination point of the stack, across the loft and do the last section in flexi, keeping it as short as possible. Ideally need to use the flexi soil vent pipe, it's better suited to this application.

 

[Madrab]

As suggested, It would be wise to use a proper soil pipe flexi adapter for the soil pipe to roof vent and only use one up to it's max length.


As Mentioned, extend the soil pipe as normal until the flexi can then reach the vent and keep the extension vertical up to the vent.

 

[AverageDIYerEssex]

Sound advice thank you everyone.

Going to whip the bag off tomorrow, test it all out to see if it's stopped pushing/pulling and if so hold my nose and get back up in the loft and connect it to the roof vent.

I can think of reasons to both yes and no to this question... but is there a necessity to avoid horizontal runs as I travel across to the roof vent and then up?

 

[dilalio]

Sound advice thank you everyone.

Going to whip the bag off tomorrow, test it all out to see if it's stopped pushing/pulling and if so hold my nose and get back up in the loft and connect it to the roof vent.

I can think of reasons to both yes and no to this question... but is there a necessity to avoid horizontal runs as I travel across to the roof vent and then up?

If it works as open vent, then add pipework with a fall on it... Enough to allow condensation (and rain ingress) to run back down to the stack.

And yes, use the proper drainage flexi.