External Air Admittance Valve ?

[denso13]

I'd be interested to learn what is wrong with the reasoning (interpretation of the Building Regs) I presented in my previous post.

Yes it does say, "where the work does not include any work to underground drainage, and includes no work to the hot or cold water system or above ground drainage, which may prejudice the health or safety of any person on completion of the work".

But in the bit in bold would fitting an AAV prejudice the health and safety of any person? Taking it to the extreme if any work to an above ground drainage system is subject to LABC involvement then that would include a leak at at WC waste or installing a washing machine trap to a sink or a new WHB trap/waste. That isn't workable, or expected.

I didn't realise that you were talking about such a magnitude of 'back (positive) pressure' - but is that really likely to arise in the absence of a blockage in the drain or sewer (which would obviously have to be addressed)?

Perhaps it would be a blockage that caused it. And with no open vent anywhere it would likely cause traps to be blown all over the place (before it was addressed). That is best avoided.

 

[denso13]

Again, is that necessarily correct?

I think so. In essence, if it doesn't work you may need a plan B.

 

[JohnW2]

But in the bit in bold would fitting an AAV prejudice the health and safety of any person?

Not (significantly) to my mind, but perhaps you would get a different answer from the person who, in advising me, wrote:

...... Methane tends to be les of an issue, but Hydrogen Sulfide is nasty stuff. It is created by the breakdown of organic matter in the absence of oxygen, attacks both metal and concrete, and the level of exposure deemed safe is quite low, with concentrations of as little as 20ppm being injurious to health.

?

Taking it to the extreme if any work to an above ground drainage system is subject to LABC involvement then that would include a leak at at WC waste or installing a washing machine trap to a sink or a new WHB trap/waste. That isn't workable, or expected.

As you say, that would not be really workable (or sensible). However, as I said, Schedule 4 consists of a list of things which are not notifiable and, although it includes things like replacing baths/loos, gutters and rain water pipes, it includes nothing about 'above ground drainage' - so, if one takes that legislation as it is written, what makes you think that such things are not (in law) notifiable (even though it would be daft if they were)?

Perhaps it would be a blockage that caused it. And with no open vent anywhere it would likely cause traps to be blown all over the place (before it was addressed). That is best avoided.

I guess that depends on how one looks at it.

I would personally be inclined to say that it would probably be better if people became aware of a blockage (and therefore could initiate the process of having it addressed) as a result of "traps been blown (by gases) all over the place" than to have to wait (with 'good venting') until what started appearing in their loos, sinks and basins (and maybe was appearing out of manholes) was a mixture of liquids and solids, rather than gases

Kind Regards, John

 

[denso13]

I would personally be inclined to say that it would probably be better if people became aware of a blockage (and therefore could initiate the process of having it addressed) as a result of "traps been blown (by gases) all over the place" than to have to wait (with 'good venting') until what started appearing in their loos, sinks and basins (and maybe was appearing out of manholes) was a mixture of liquids and solids, rather than gases

And remove all electrical safety devices as a good sharp shock is better

Not (significantly) to my mind, but perhaps you would get a different answer from the person who, in advising me, wrote:

I can't explain that but to use an electrical analogy, again, 230v is always potentially dangerous. Where do you draw the line?

As you say, that would not be really workable (or sensible). However, as I said, Schedule 4 consists of a list of things which are not notifiable and, although it includes things like replacing baths/loos, gutters and rain water pipes, it includes nothing about 'above ground drainage' - so, if one takes that legislation as it is written, what makes you think that such things are not (in law) notifiable (even though it would be daft if they were)?

I don't profess to have all the answers but reasonableness must come into it. After all,

"where the work does not include any work to underground drainage, and includes no work to the hot or cold water system or above ground drainage, which may prejudice the health or safety of any person on completion of the work".

Did you involve LABC with your tap replacement?

 

[JohnW2]

And remove all electrical safety devices as a good sharp shock is better

I don't think that's a fair analogy. Don't you agree that it is better if the thing that first brings a blockage (of drain/sewer) to one's attention is smelly gas bursting/bubbling out of loos/basins/sinks/whatever than for the first 'sign' to be when sewage starts backing up into those loos/basins/sinks/whatever?

As for your attempt at an analogy, we do always have to remember that, in a wide range of fields, introduction of protective measures can result in complacency, thereby undermining some of the potential protection afforded by the measures. ... i.e. I'm sure there will be at least some people who (even if 'subconsciously) be less careful when playing with electrical things than they would were it not for RCD protection, and at least some people who drive 'less carefully' than they would if their cars didn't have seat belts, airbags, crumple zones, ABS etc. etc.

I can't explain that but to use an electrical analogy, again, 230v is always potentially dangerous. Where do you draw the line?

As you know, that is often debated, and has to be a matter of personal judgement but, again, it's not really pertinent to what we're talking about here

I don't profess to have all the answers but reasonableness must come into it. After all,

It should, but unfortunately, that's not always the case with laws.

However, I've looked more closely and have found what may be the cause of the confusion (even though it doesn't really 'clarify' anything).

I had forgotten that, whilst the Building Regs require all 'building works' (other than most electrical work) to be notified unless they are explicitly exempted in Schedule 4, it's definition of 'building works' is pretty limited (as well as very unclear!!). The nearest to anything relevant in the Intr0duction is the statement that anything counts as 'building works' if it is a 'cotrolled service' which, in turn, it defines as something for which requirements are imposed by any of a number of 'Parts' in Schedule 1, including 'Part H'. However, when one looks at 'the requirements of Part H', if one ignores those relating to septic tanks, cesspools and 'building over sewers', the only 'requirements' seem to be that 'there should be provision for' disposal of foul water and rain water. Nothing else!

So, I'm not sure where that leaves us. There are all sorts of things said about plumbing work and LABC - some, like you, saying/believing that some things (like above-ground drainage) are not notifiable, and others saying/believing that some things (like installing new loos etc.) are notifiable - but in neither case can I work out where those beliefs come from.

"where the work does not include any work to underground drainage, and includes no work to the hot or cold water system or above ground drainage, which may prejudice the health or safety of any person on completion of the work".

Did you involve LABC with your tap replacement?

Of course not, any more than I intend to involve LABC in what we're talking about here - but, as above, I don't know whether that is 'correct' (per 'rules'/laws) or not!

Mind you, I've highlighted above the bit of the statement that you forgot to also highlight Having said that, if you recall that discussion about my tap turned into a many-page debate when someone jumped in and suggested that if I replaced the tap without including a check valve, I would be contravening regulations and putting people at risk of Legionella infection - so maybe, in their opinion, "prejudicing the health or safety of any person on completion of the work"?!!

Kind Regards, John

 

[JohnW2]

..... You don't need LABC and .....

@denso13 - maybe you can help me?

You will recall that, in response to your comment above (at least twice) I explained that I was struggling, on the basis of what is written in the Building regs, to work out what plumbing/drainage work actually is 'notifiable' (i.e requires LABC involvement).

I would imagine that underground drain probably is (should be) notifiable, although I can't find anything which explicitly says even that.

However, beyond that, I wonder what other types of plumbing/drainage works (if any!) are, in your opinion (and 'strictly speaking') notifiable (i.e. require LABC involvement) - and, if possible, what brings you to those beliefs.

You have previously talked about "reasonableness" (i.e. common sense), but that doesn't always seem to work in relation to these matters. For example, as you may know, it is the case that in Wales, virtually any electrical work in a kitchen, no matter how trivial, is ('strictly speaking') notifiable.

Kind Regards, John

 

[Swwils]

Some situations demand use of a vent and a AAV wouldn't be allowed weather proof or not. This can depend on your neighbours configurations too.

It was the condensation freezing that did in the old ones.

 

[JohnW2]

Some situations demand use of a vent and a AAV wouldn't be allowed weather proof or not. This can depend on your neighbours configurations too.

Do I take it that you're saying the same as many others have said - namely that there needs to be open vent of the drainage system somewhere fairly nearby?

It was the condensation freezing that did in the old ones.

Yes, that is the assumption and was discussed at the very start of this thread. However, as I've said, unless there is something else they're not telling us, it seems that the only difference between FloPlast's 'internal' and 'external' AAVs (other than about £20 price difference!) may be that the external one has a 'fly screen'.

Kind Regards, John

 

[Swwils]

AFAIK there is no set distinction in the type testing between internal and external AAV with BS EN 12380. It's possible they do use a different stabilizing agent in the external one for it to actually survive outside.

While there may not be a technical standard differentiating between the two, manufacturers may have specific guidelines on where their AAVs are best used, considering factors like durability against external weather conditions, and these guidelines should be followed as you have experienced - insect mesh was also a common one.

and yes the vent requirement is mainly a protection against pressure changes and also gas discharge - so you do sometimes need a vent to maintain the correct balance between the interconnected systems of each property.

A similar situation kind of arises with white goods where you could theoretically require whoever was installing it to own or consult all the relevant standards for the product and considering they can be £800 or so each it gets a bit silly, so at some point you do eventually have to place some trust in the supplier.

 

[denso13]

However, beyond that, I wonder what other types of plumbing/drainage works (if any!) are, in your opinion (and 'strictly speaking') notifiable (i.e. require LABC involvement) - and, if possible, what brings you to those beliefs.

Hmm. I've changed this post a few times now having thought about it and as you know the actual building regs are a (very) high level statement of the "law".

And, that leads to approved documents which give methods of deemed compliance, but they are guidance/not law/and you can demonstrate other methods of compliance (you know that).

What do I think? The problem is what building control officers think. Sticking to plumbing I think that underground drainage alterations need approval because it is important that it operates correctly. I think that above ground drainage needs "checked" if there is a substantial change to routes which may need a soundness check to ensure "all is ok". Gas installs need approval because it is inherently dangerous and hot/cold pressurised system need approval because they could also be dangerous.

I have mentioned that I came to blows on a few occasions with building control, once it cost me a substantial amount of money and customer goodwill to open up foundations on a new build. I and my engineer were correct, no further action.

I'm not sure if what I think is strictly in line with what is notifiable. There is no point arguing with who you have to deal with on the ground.

However, if anyone thinks they are correct, having regard for the legislation, then crack on.

 

[Swwils]

Amazed you had a BCO that was that interested, reassuring in a obviously annoying way for you.

 

[denso13]

Amazed you had a BCO that was that interested, reassuring in a obviously annoying way for you.

No, I'd go as far as to say they were corrupt and had no right to do what they did. Not really reassuring.

 

[Swwils]

Faith in humanity restored! Lol

 

[denso13]

Faith in humanity restored! Lol

Erm, ok. Whatever that means.

 

[JohnW2]

Hmm. I've changed this post a few times now having thought about it and as you know the actual building regs are a (very) high level statement of the "law".

Yes, but the Building Regs ARE 'the law', and it's only that law which can impose a legal requirement to notify certain types of work.

And, that leads to approved documents which give methods of deemed compliance

Yes, deemed to be compliant with Part H of the Building Regs but, just as with Part P, Part H says virtually nothing specific that one needs to 'comply with'. As I said before, the only relevant requirement of Part H appears to be that "there should be provision for" disposal of foul water and rainwater, which no mention of how that is achieved.

In any event, I'm not talking about 'compliance' but, rather, about the legal requirement to notify (if such a requirement exists for any plumbing/drainage work) - and, as above, only the Building Regs themselves could impose such a legal requirement (as they do for a small number {in England} of types of electrical work)

What do I think? The problem is what building control officers think.

Not in relation to what I asked you. BCOs may well (and do!) have their own ideas about what practices are 'acceptable', but they cannot have any control over what (if any) legal requirements there are to notify ('involve LABC in') plumbing/drainage work.

Sticking to plumbing I think that underground drainage alterations need approval because it is important that it operates correctly.

As I said, that is certainly what I would expect, but I can't even find anything which says that.

I think that above ground drainage needs "checked" if there is a substantial change to routes which may need a soundness check to ensure "all is ok".

So are you sayingv that such work is 'notifiable' (i.e. do you have to 'involve LABC') or not?

Gas installs need approval because it is inherently dangerous and hot/cold pressurised system need approval because they could also be dangerous.

There are requirements in relation to gas work imposed by legislation other than the Building Regs, and the same may be true (I have no idea) of pressurised systems. Part H of the Building Regs does not seem to mention either.

I have mentioned that I came to blows on a few occasions with building control, once it cost me a substantial amount of money and customer goodwill to open up foundations on a new build. I and my engineer were correct, no further action. I'm not sure if what I think is strictly in line with what is notifiable. There is no point arguing with who you have to deal with on the ground.

I think you may be missing the point, and the point of my question. If something is not 'notifiable', then you don't have to 'deal with' anyone at all in relation to it!

Is the problem that I'm talking about 'notification'? Would you be able to answer better if I asked you in relation to what works you believe you are required 'to involve LABC'?

As I said before, I have seen/heard all sorts of things being asserted about various types of plumbing work (e.g. installing a new WC) which need to be 'notified' (or undertaken by a member of a relevant CPS, which is essentially the same), but I'm afraid I'm still no closer to knowing whether any of that is actually true.

Kind Regards, John