Durgo valves and building regs

[Lobster]

I'm refurbishing a bathroom which has an internal soil stack, which vents through the roof, and means that the corner of the room above the loo is occupied by a large amount of boxing in, about 15" x 18" up to the ceiling. What I'd like to do is remove all this boxing, and fit a Durgo valve to the stub of the soil stack (level with the close-coupled cistern) and then box it in again, but with a 'top' at "worktop" height.

(1) Would I need to get Building Regs consent to do this (note - next door has the same arrangement, ie they still have a vented soil pipe through the roof)

(2) Is my proposed change OK, ie with the Durgo valve enclosed within boxing rather than open to the roof space, say? Should it maybe have vents installed in the boxing?

Thanks for any comments

David

[Set Square]

I imagine that you'd need building regs approval. AIUI, you can only use Durgo valve when there's a *proper* vented stack within a specified distance. So if you had a row of houses, all with vented stacks, it's probably ok if one or two convert them to Durgos - but not if they *all* do!

[T i m]

What I'd like to do is remove all this boxing, and fit a

This looks like it could be a good answer .. (of sorts) ;-)

the best ..

T i m

[Richard Conway]

It may be possible to reduce the diameter of the soil stack above a certain point (I think it was talked about on here recently) - this might at least make the boxed in section less obtrusive?

[Adrian Brentnall]

I'd be able to confirm for certain if only my local Building Control department got the backsides into gear and answered my letters / phone calls etc........

....but as I understand it you can't 'just' use an Air-Admittance valve - there has to be a 'real' vent to the open air. Additional stacks can be Durgo'd - but in our case (drains go to our own private septic tank) I need to reinstate the vent through the roof that was removed and Durgo'd by the previous over-enthusiastic owner.

Like you - I end up with an unsightly bit of boxing in - but, if it helps, I believe that you can reduce the vent pipe from 4" to 3" once you are level with the sink overflow - so this can help to make the boxing in slightly less obtrusive.....

If I ever get communications from my darling BCO then I'll let you know - after all - it's only been 3 weeks....

Adrian Suffolk UK

======return email munged================= take out the papers and the trash to reply

[Hugo Nebula]

On Wed, 05 Oct 2005 14:05:02 GMT, a particular chimpanzee named Lobster randomly hit the keyboard and produced:

Strictly speaking, yes. Any work to a controlled service or fitting, which includes any part of the drainage system, which, at any stage, could result in the building being more unsatisfactory in relation to an applicable requirement requires an application.

Unofficially, no BCO would thank you for an application that just consisted of a minor alteration such as replacing a vent stack. Provided that you carry out the work correctly, there's less than a minuscule chance of any enforcement action being taken even if you get found out.

It's a case where ignorance is bliss. If you ever come to sell, you are asked whether you've ever carried out work which required an application. If you didn't know that you needed an application for the work, you can reply in the negative. Whether you could live with your conscience is down to you ;-)

Yes, it should be vented. It should be installed above the flood level of the highest appliance (i.e., the wash-basin).

[Lobster]

What application? What work?

What conscience? :-)

Great, thanks for that. It would make a big difference to the look of the room I reckon (hypothetically speaking, of course!)

David

[Doctor Drivel]

You can use an AAV if the house is not the end of line and is not every 4th or 5th house, which must be vented. Septic tanks? See the makers, but usually you need open vented.

[Paul Andrews]

snip

So if my understanding is right, you will lose about half to two thirds of the vertical column of the stack and still be left with with the stack up to top of the basin height? When we install a WC in the current utility room, I guess we'll need a Durgo there (it won't be connected to the existing soil stack).

Paul

[zikkimalambo]

Ware the Durgo!

We had a similar setup here to what you propose, and all went well until someone put 2 carrier bags worth of raw meat into the sewer.

For some reason there was positive pressure in the sewer and this caused the anti syphon traps on the kitchen sink to let the stench into the house. We had a very unpleasent couple of weeks until my brother in law removed the offending meat and fitted a proper vent pipe above the eaves.

If I were you I would either;

Leave it as it is.

Remove the boxing in and paint it.

Convert to 3" above basin height and install smaller boxing.

or

Install 3" and paint it.

[<me9]

I used an unvented sub stack for my utility room/downstairs bog. BC were quite happy as it complied with the rules.

[Doctor Drivel]

Wrong thing to have done. Should have fitted Hepworth HepVO traps on all the sinks and basins. Then no needs for an AAV valve at all and NO stench will ever get into the house.

[Lobster]

My reply to a related thread just now has triggered a thought about the above... in my own house, we have an ensuite which uses a Durgo valve as fitted by a plumber, but it's definitely not higher than the nearby wash basin; in fact it couldn't be due to the height of the dormer roof at that point.

I'm trying to work out the worst-case scenario here - what *could* happen? Are we talking leakage of sewage out of the AAV if the sink got blocked? Not sure how that would happen.

David