Advice about Durgo Valve height

[Hayman]

Hi, renovating my bathroom and need some advice about the air admittance valve I have in place. It was all boxed in but I would like to hide it in a toilet / vanity unit. Is it ok to cut down?

thanks

 

[Sparkgap]

Should be above the highest drainage point, so ideally above the outlet from the basin. Saying that, I've seen plenty with just a tee piece and the durgo plonked on top. :disappointed:

 

[Hayman]

Thanks for the reply! When you say highest drainage point, do you mean the plug hole or the overflow of the sink?
what would happen if I cut it down? Any other ideas as I don't really want a big box around it?

Cant add pics as in new to the forum

Thanks

 

[myles]

As above the durgo valve needs to be above the highest overflow on the system (not the plughole lol)!

 

[AWheating]

150mm above basin top will be good. needs to be accessible for maintenence and ventilated aswell.

 

[josh]

150mm above basin top will be good. needs to be accessible for maintenence and ventilated aswell.

I know that is right but when have you ever seen them fitted like that?
i'm sure i have fitted one that said on the box can be fitted below spill over level,
cant core a hole outside and vent out there?

 

[AWheating]

so are you saying because you have never seen it done right you should do it wrong?

 

[AWheating]

a couple of penny/sofit vents in the boxing should do for ventilation.

 

[josh]

I am saying you try and tell any developer/ builder this they will laugh in your face. Plus would i hell want a soffit vent in my bathroom.

 

[AWheating]

I am saying you try and tell any developer/ builder this they will laugh in your face. Plus would i hell want a soffit vent in my bathroom.

oh ok its on a builders job. just put it into an email to cover yourself, noting it needs venting, it needs to be above water levels etc.... let the builder box it in as he wants, if problems happen then send him the email pointing out its his problem.

i have the same issues with builders, i try to fit my durgos in the loft space above insulation but most builder know better than you sadly. Vents do look bad in bathrooms but your supposed to vent the boxing, if you leave the boxing vented to the loft it will prob fail the air test and they will expanding foam it anyway.

you cant win, you can only try.

 

[AWheating]

did a job with an nhbc inspector that made the builder conform to the regs, the svp boxings were 10" square with vent grills etc.... it did look weird but then it was correct. made the builder make the boxing big enough that you could remove the dergo and replace it through the vent grill fitted at high level. he made me use pushfit durgo's over glued so they could be removed easy.

he also meausred the clipping distance on the svp, i asked him to prove the correct distance in the regs and he could not. But i was glad he was good at his job.

 

[josh]

I agree you can but try but just end up banging your head against a brick wall, to be honest the last 5 houses we have done have all had frames with false walls so not so bad.
All fun and games.

 

[AWheating]

games yes, not sure about the fun tho 🙂

 

[chris watkins]

Am I missing something Durgo's like access cap can be installed so they are above the overspill level of the WC pan (if we are talking about a 110mm one on the main stack) Why would it need to be above the highest fitting ?

How often do they open ? Very very rarely if at all, in most 2 story domestic stacks.
If they do open how much air is drawn in to equalise the negative pressure again very little so lone as the boxing isn't very small & air tight it will be OK.

 

[josh]

Yet to see a building inspector check the dirgo's. All they want to see here is that the head of the drain is vented to outside which that always is and that the cylinder PR has a cage on it.
fitting the boiler and cylinder is but the bathrooms Arn't so fun.

 

[AWheating]

Am I missing something Durgo's like access cap can be installed so they are above the overspill level of the WC pan (if we are talking about a 110mm one on the main stack) Why would it need to be above the highest fitting ?

How often do they open ? Very very rarely if at all, in most 2 story domestic stacks.
If they do open how much air is drawn in to equalise the negative pressure again very little so lone as the boxing isn't very small & air tight it will be OK.

must be installed above spill over level of highest fixture/ appliance. they need venting, most new builds boxings are sealed to pass air testing. its unlikely im sure but they could need a fair bit of air flow under fault conditions.
most manufacturers recommend roof space termination.

 

[chris watkins]

must be installed above spill over level of highest fixture/ appliance. they need venting, most new builds boxings are sealed to pass air testing. its unlikely im sure but they could need a fair bit of air flow under fault conditions.
most manufacturers recommend roof space termination.

Think about it AW, how is it going to vent the waste runs connected to the stack fitted with the Durgo valve for this you would have to fit the mini type on each branch waste pipe.

Having it placed much higher than the overspill of pan will serve little purpose as blockages in stack will mean water will only reach overspill of pan before they get the idea it's blocked & stop using the fitting leaving the Durgo still dry.

I take the point about sealing up boxing now days but even so it is very unlikely to cause a problem how many have you seen fail & how many that fail pull traps ??

 

[Hayman]

Thanks for the replies, some different opinions between you. Regs aside, would it work for my to cut Down a durgo valve below a worktop and have a sink on top of the worktop. The sink bend would be below the top of durgo so should work?


thanks

 

[tolly]

I would check with manufacturers, some of them say they can go bellow the flood level