new bathroom- air admittance valve problem

[9000]

The initial message was deleted from this topic on 17 March 2019 at 01:24

[DrDeAtH]

you cant cut it down in height, but you can either vent out through an external wall with the AAv at the correct height, or go full height - 600mm above the eaves with just an open vent.
or... could you cut the wall vertically and duct up into the loft, then either AAV or open vent though a roof tile vent.

pics would help...

[Simpo Two]

My bathroom originally had a 'stink pipe' that ran in ugly tiled boxing up one corner to the roof.

When I revamped the bathroom I ripped out the boxing and (after due consultation with my local plumbing shop), cut the stinkpipe down to below bath height and stuck an AAV on it:



Basin and bog go in the left, bath goes in the right.

It now looks like this:



Five years on and no probelms at all.

[Ricky_M]

The AAV should be at least the height of the basin spillover level.

I'd imagine that reg is in place to prevent water escaping out of the AAV if there was a blockage in the pipework somewhere.

I personally wouldn't be too worried about the basin height, but I'd want it at least higher than the toilet spillover.

[dirkgently]

Do you need an AAV at all?
Is that pipework the finished article? If it is I might just go and have a gentle weep.

Edited by dirkgently on Tuesday 26th April 06:57

[DrDeAtH]

yes, you need to have ventilation to the soil stack otherwise you may cause a vacuum within the pipework when flushing the loo, which could result in the water being sucked out of the u bend completely.

[ATTAK Z]

If you vent externally you need to be 900 above any openable windows ......... but you can do it in 50mm pipe (it doesn't have to be 110mm)

I think

[dirkgently]

DrDeAtH said:

yes, you need to have ventilation to the soil stack otherwise you may cause a vacuum within the pipework when flushing the loo, which could result in the water being sucked out of the u bend completely.

If the head of the drain is vented and he is not on the nineteenth floor or has a dozen W.C`s conected to the stack I see no reason for a stub stack.(although site conditions may deem one necessary)