Are building standards optional?

[AkiraDIY]

I'm currently in dispute with a builder regarding an installation of a kitchen extract duct. They've basically cut the rigid PVC pipe too short, used around 6ft of flex ducting, and is completely uninsulated/no condensate drain fitted. The flex ducting is compressed, unsupported, loops/sags on itself, and is joined with duct tape only.

When I contested that out of the ~22 guidelines for flexible and rigid ducting stated in Scotland's "Building Standards Technical Handbook 2023: Domestic", 10 are not applicable, 10 are in non-compliance, and at best 2 are compliant.

They justified the 6ft of unsupported, compressed, sagging flex by saying "our roofers are in attics every day and they see these flexible pipes some of them being more than 6ft long".

They justified cutting the PVC pipe too short by claiming "We originally ordered the rigid pipe to do this job but when applied we found it was too heavy due to the length and it would have put too much pressure on the macflash and possibly pulled it through the roof the roofers decided to use the flexi pipe"

I don't think what other people have installed is relevant as (correct me if I'm wrong) following Building Standards is a legal requirement, not optional based on what others have got. 2 wrongs don't make a right.

Also, is macflash supposed to be used as a vertical duct support? I thought it was for weather sealing only. Either way, I imagine supporting a vertical duct at only the macflash will eventually lead to premature failing of the weather sealing.

Can someone tell me if they're just BS-ing me or am I interpreting the Building Standards too strictly? Or are Building Standards just a recommendation and don't need to be followed at all as the work doesn't require a building warant?

 

[^woody^]

If the Building Standards apply to whatever works you are doing, then they apply in general terms, and the guidance is merely guidance in how to achieve compliance. ie if the Standards require a fan, then just by fitting a fan and ducting, that complies. The method or quality of the fitting is a separate issue. Many people are caught out by this, as Building Standards/Regulations are a very basic level of quality.

You should have property specified the work you want doing and specified what Standards (ie what level of quality) your builder is required to meet. You can specify whatever you like, as long as the builder knows what you are expecting. This forms the basis of your contract

If you have not specified the standard required, then you can rely on the manufacturer's installation guides/requirements. This can be useful as they often include compliance with various BS/EN Standards as part of their guidance.

Failing that you are in the realms of what would a professional be expected to do. And for this, you'll need another, better, more qualified person to comment and normally then a Judge to decide at court.

But yes you are correct that "this is what I saw, or done on my last job" is not an acceptable justification.

 

[AkiraDIY]

thanks for the reply. I find it frankly ridiculous that you need to specify to a builder not to cowboy a job and follow the building regs. That should really be the default. That brings me back to the question, what is an "guideline" and what is a legal "requirement"?

For example, I've copied in what the building standards say about ductwork that I think applies to this job and how they've cowboy'd it in. It says "General Recommendations" and the use of "should" instead of "shall/must" insinuates it's a guideline? Can I use any of that as grounds to not accept the quality of their work?

Building standards technical handbook June 2023: domestic

3.A.8 Ventilation Ductwork
General Recommendations

Ducting should be:
• routed in a manner which minimises overall duct length and the number of bends required. It is particularly important to minimise bends in main ducts operating at higher air velocities. (flex duct loops back on itself)
• insulated where it passes through unheated areas with the equivalent of at least 25 mm of a material with a thermal conductivity of not more than 0.04 W/mK. This reduces the risk of condensation occurring within the duct (duct goes via a cold loft space. Totally un-insulated duct although I would be fine if a condenstate trap was fitted)
• insulated or be fitted with a condensate trap where a duct extends above roof level. The condensate trap should be fitted just below roof level (no condensate trap)
• fitted with a condensate trap where it is installed vertically. The trap should prevent condensation flowing down the duct and potentially damaging a mechanical extract fan (no condensate trap)
• arranged to slope slightly downwards away from the fan unit, to prevent backflow of any moisture into the unit, when installed horizontally (loops and sags all over the place)

Flexible ducting

• Rigid ducts should be used wherever possible. Where flexible ductwork is installed, this should only be used for final connections and duct lengths should be kept to a minimum. All flexible ductwork should meet the standards of BSRIA BG 43/2013. (the flex is around 6ft long)
• Ducting should be pulled taut to ensure that the full internal diameter is obtained and flow resistance minimised. This is considered to have been achieved if the duct is extended to 90% of its maximum length (flex is largely compressed)
• Flexible ducting should be supported at suitable intervals to minimise sagging. Refer to manufacturer’s information but generally it should be supported at no greater than 600 mm intervals (flex isn't supported)
• Bends in ducts should have a minimum inside radius equal to the diameter of the duct. If tighter bends are required, rigid bends should be used. (Flex does a tight hairpin bend on itself)

Duct Connections/Terminals
• Connection of lengths of flexible duct must use a rigid connector and jubilee clips or similar to ensure a long term seal is achieved. Connections of lengths of flexible duct should not be taped only. (used duct tape only)
• Connection of components should not result in significant air flow resistance. Components should be proprietary and fit easily together without distortion. (the flex is nothing but resistance and distortion)

I've also spoken with Consumer Advice and they reported the builder to Trading Standards. They said that my options were to request a discount (the builder has refused on multiple occasions) or take them to a small claims court.

The complete bill is around £400 but the small claims process costs £110 to start. So it would be a bigger waste of my time and money than this already is. I feel like I have no other choice than to pay these cowboys and then pay someone else to rip out their mess and start again. Absolutely sucks

 

[^woody^]

I find it frankly ridiculous that you need to specify to a builder not to cowboy a job and follow the building regs

The thing is, the building regulations are not prescriptive. They define an end result but not how to achieve it. And they do not cover quality at all.

Likewise with many BS, EN or suchlike standards. They don't define how standards are to be met, and there can be overlap - so which specific standard should be met can be confusing.

That is why it's imperative that the client clearly defines and prescribes what the builder must do - in the form of a specification or work schedule, and not let a builder dictate what he wants to do. Most people just rely on the builder's quote.

 

[AkiraDIY]

I don't fully follow though. Some of the standards for ducting that I posted above are clearly quantifiable.

Like flex should be limited to max 1500mm, extended to 90% of it's maximum length, a condensate trap fitted on vertical duct, joints not taped only, etc.

That is effectively telling you what the end system should be/look like. So aren't Building Standards with a clear target like that mandatory to be followed?

 

[Murdochcat]

That is effectively telling you what the end system should be/look like. So aren't Building Standards with a clear target like that mandatory to be followed?

I wish!

 

[AkiraDIY]

I wish!

Care to elaborate?

I agree that many regs are ambiguous however, some are also very prescriptive. Such as, the regs say flex length should be limited to 1500mm, how can that be interpreted as anything other than keeping the length below 1500mm?

If I use 2000mm of flex, I've disregarded the regs. Short of drawing it in crayon, I don't think that particular reg, for example, can be any clearer on how to comply. So if the regs are mandatory, how can a reg like that be legally ignored?

 

[Odds]

You should have property specified the work you want doing and specified what Standards (ie what level of quality) your builder is required to meet. You can specify whatever you like, as long as the builder knows what you are expecting. This forms the basis of your contract

If you have not specified the standard required, then you can rely on the manufacturer's installation guides/requirements. This can be useful as they often include compliance with various BS/EN Standards as part of their guidance.

Failing that you are in the realms of what would a professional be expected to do. And for this, you'll need another, better, more qualified person to comment and normally then a Judge to decide at court.

But yes you are correct that "this is what I saw, or done on my last job" is not an acceptable justification.

How is somebody to know what specifications to ask for if they're not equipped to be specific in framing the relevant questions?

 

[mrrusty]

There is another way of looking at this. In all contracts there is an implied obligation for the deliverer of the product or service to do so with reasonable skill and care. A measure of what is RSC is compliance with any guidelines, which although not mandatory do indicate the agreed standard that a professional deliverer of that product or service should adhere to. If they deviate, it doesn't necessarily mean the alternative is wrong, but it does it make it a bit harder to show it's right.

To pursue bad workmanship you have to claim negligence i.e. you have suffered a loss (cost to correct) because the contractor has failed to use RSC. If you do claim this in a court, then the contractor would have to show why they were not negligent.

Having said all that, no way would I bother with all the hassle of litigation for a bit of ducting from a cooker hood! If you haven't paid him, tell him you'll pay after you've tested it. Set a couple of big pans of water to boil, switch the extract on when it's cold outside, and let it boil the water away. If the condensate drips down or accumulates in sags, it's failed, and is demonstrably not fit for purpose. You then have robust grounds to not pay, and no obligation to pay for faulty workmanship.

"fit for purpose" is the key. An extract system should reliably extract, irrespective of compliance with guidelines.

 

[AkiraDIY]

Attached some pictures of the work I'm not happy about (ignore the insulation, it's in the process of being replaced). Is it acceptable and I'm just being too strict with my interpretation of the regs?

There is another way of looking at this. In all contracts there is an implied obligation for the deliverer of the product or service to do so with reasonable skill and care. A measure of what is RSC is compliance with any guidelines, which although not mandatory do indicate the agreed standard that a professional deliverer of that product or service should adhere to. If they deviate, it doesn't necessarily mean the alternative is wrong, but it does it make it a bit harder to show it's right.

If the install was tricky, then I understand if some guidelines were stretched. But the system is in clear space, easy access, and the replacement pipe was a suitable length to minimise the flex until they cut it. I know they cut it cause they left the rubbish behind.
I don't see any valid reason for doing it the way they did and other than laziness/incompetence, incorrect materials to hand, and wanting to get it done as quickly/cheaply as possible.
It just annoys me that they cut the PVC pipe too short (the end of it is at the top of the first picture) then tried to BS it as intentional due to weight. If the weight of 2ft of pvc pipe matters, the fixings used are insufficient.

Having said all that, no way would I bother with all the hassle of litigation for a bit of ducting from a cooker hood! If you haven't paid him, tell him you'll pay after you've tested it. Set a couple of big pans of water to boil, switch the extract on when it's cold outside, and let it boil the water away. If the condensate drips down or accumulates in sags, it's failed, and is demonstrably not fit for purpose. You then have robust grounds to not pay, and no obligation to pay for faulty workmanship.

I know going via the small claims court is a tiresome process, but I get the feeling the contractor knows that and is banking on me not going through with it. I haven't paid yet purely because I'm disputing the workmanship and they haven't finished the job (cleaning up after themselves was part of the contract. They've been out twice, and twice they didn't bother and just gave excuses)
I've had the fuseboard trip twice when running the extract for long periods, which has never happened before. I don't know if it's due to condensation or just coincidence. I'd have to remove their duct tape "connections" to be able to check if condensation is accumulating in the sags or not though. Is that worth doing?

 

[mrrusty]

What a load of bodge!. The fact that it is tripping out the electrics proves this. IMHO there is no way that is going to work - it's just going to be a condenser - warm damp air going up in to a cold pipe - the condense is going to run straight down in to the fan, which is possibly why it's tripping.

It's not going to make much difference if the pipe is flex or solid as far as creating condensation, but you need solid pipe to fit a condensation trap https://www.extractorfanworld.co.uk/blogs/condensation-traps

Tell him it isn't fit for purpose and to do it again properly and don't pay him for this element of work until he does. I do hope the rest of the work has been done with a little more care to detail!

 

[Lower]

Care to elaborate?

I agree that many regs are ambiguous however, some are also very prescriptive. Such as, the regs say flex length should be limited to 1500mm, how can that be interpreted as anything other than keeping the length below 1500mm?

If I use 2000mm of flex, I've disregarded the regs. Short of drawing it in crayon, I don't think that particular reg, for example, can be any clearer on how to comply. So if the regs are mandatory, how can a reg like that be legally ignored?

The key word in that is 'should'. If a standard is prescriptive then it will say 'must'.

 

[mrrusty]

If a standard is prescriptive then it will say 'must'.

standards are very, very seldom prescriptive. They are almost always guidelines. This is how BSI refers to standards:-

"BSI defines a standard as 'something that is generally accepted'. British Standard (BS) publications are technical specifications or practices that can be used as guidance for the production of a product, carrying out a process or providing a service."

Not to be confused with regulations which as @^woody^ says above, describe what the end result must be, not how to do it/get there. As I said in a post above, standards can be used to prove or disprove reasonable skill and care, which if not delivered can lead to a claim for negligence or fitness for purpose. (but you cannot legally pursue someone just because they have not adhered to a standard)

 

[Nakajo]

Remember, with reference to the Approved Documents, the Regulations are the little bits of text in green boxes. The rest is merely a method of compliance with those Regulations. As long as you can demonstrate compliance, you're free to deviate from the guidance.

 

[AkiraDIY]

Tell him it isn't fit for purpose and to do it again properly and don't pay him for this element of work until he does. I do hope the rest of the work has been done with a little more care to detail!

I've told the builder on multiple occasions that the bodged install isn't acceptable and I'm not paying a penny until it's fixed. They've consistently replied with variations of "it's just a pipe to direct air outside", "it doesn't look the best but it won't be a problem""it's fine, we see this in attics all the time", "all ducting is unsupported flex in my house and it's a new build, therefore it must be compliant", and other obvious lies to avoid responsibility.

I gave them multiple chances to fix it and they just responded with blatant BS every step of the way. I no longer have any faith that they will do it properly or are even capable of doing of doing so, so I don't want them anywhere near my flat again. I'd much rather they gave a discount for a job unfinished and not as agreed but they won't even admit anything is remotely wrong to begin with.

The rest of the work was on the roof, which I cannot check. They're roofers by trade, so I'll give them the benefit of the doubt, even though I probably shouldn't.

Remember, with reference to the Approved Documents, the Regulations are the little bits of text in green boxes. The rest is merely a method of compliance with those Regulations. As long as you can demonstrate compliance, you're free to deviate from the guidance.

As far as I can tell, Approved Documents are a England/Wales thing. Scotland has Building standards technical handbook June 2023: domestic. However, what is specifically a regulation and what is a guideline doesn't seem to be clear. What is clear though is that these builders haven't followed any of the guidance and in all likelihood aren't even aware of them.

What a load of bodge!. The fact that it is tripping out the electrics proves this. IMHO there is no way that is going to work - it's just going to be a condenser - warm damp air going up in to a cold pipe - the condense is going to run straight down in to the fan, which is possibly why it's tripping.

That's what I'm thinking but I'm not sure yet. The system has 2 fans on it, the blue one pictured and a vent axia on the kitchen ceiling installed by the previous owner. It's an internal kitchen with no windows, I think building control required them to increase airflow and sticking a fan inline was probably the cheapest way but I'm not sure.

The blue fan has stopped working since after the install. Again, don't know if it's coincidence or condensation, but either could result in the electrics tripping. I'm going into the loft this weekend to put away the christmas decorations, so I'll un-tape one of the sagging flex's and see how much condensation has actually accumulated.

As I said in a post above, standards can be used to prove or disprove reasonable skill and care, which if not delivered can lead to a claim for negligence or fitness for purpose. (but you cannot legally pursue someone just because they have not adhered to a standard)

I can see no reason, nor was it agreed, for them to do the job the way they did. I specifically requested that the old rigid duct was replaced with another rigid duct; not 2/3 rigid, 1/3 flex. The only explanation I have is that the builder was either completely unqualified or it's a "job and knock" situation. Access isn't difficult and a wobbly bit of wood with copious amounts of duct tape compressing the flex for "support" doesn't demonstrate care, skill, nor a builder with any pride in their work IMO.

The final invoice is around £400, so it's not really worth my time to go to a small claims court. But because they've been so deceitful/incompetent about fixing their mess, I'm seriously considering it. Consumer Advice have already reported them to trading standards based on the replies of the builder. I honestly don't think they have a leg to stand on to demonstrate reasonable skill and care.