# Grenfell Tower: Should this cladding be allowed?



## bobclive22 (Apr 5, 2010)

This is a technical post regarding building regulations for high rise buildings in the UK, the comments are meaningful and can all be verified.

http://www.bdonline.co.uk/grenfell-towe ... 61.article


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## Spandex (Feb 20, 2009)

Need to be registered to view the article.

As for the cladding, I think it's telling that a large number of countries don't allow the non fire proof version of it on buildings above a certain height, and this tragedy clearly illustrates why. If you can't reach it to put it out, it should be fire proof - seems simple enough.


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## NickG (Aug 15, 2013)

The cladding isn't the problem, the incorrect use of it is! For low rise, commercial and industrial buildings the standard PE(polyethylene) core composite cladding is a brilliant material. Low in cost, the ability to make large visually appealing panels makes it perfect for the job. You'll often find it on Dealership entrances such as Audi and Porsche for the modern sleek finish you can achieve.

Should the PE core material be used on residential buildings? IMO yes, low rise buildings will have no problem, if there's a fire then you exit the building and everyone is safe (How long have timber cladding and thatched roofs been around - there's a time and a place!). The PE core material cannot be used on an NHBC project with a building height above 18 metres, it's therefore recognised in the UK that it's not suitable for high rise buildings by at least one major Council. The fact that this material was used on such a recent renovation is nothing short of criminal and the ONLY people that i think need to answer to this terrible tragedy are the professionals involved with the build who were paid to know better.


For reference there are a further 2 types of composite panels that could have and should have been used;
FR core (Fire resistant) - A non-inflammable mineral based core which achieves Fire Class 0 in the UK.
Aluminium Core - Non-combustible Fire A2 rated & suitable for use on all buildings, including those over 18m high.

What's frustrating is that the FR core is only £3/m2 more then PE on average and would have made a massive massive difference to the events of last week.

In summary with correct specification ACM(aluminum composite material) is a brilliant product and there's absolutely no need to ban it.


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## Spandex (Feb 20, 2009)

NickG said:


> The fact that this material was used on such a recent renovation is nothing short of criminal


I thought the whole problem was that it *wasn't* criminal. I've not looked into it in detail, but I understood that the use of PE panels on high-rise residential buildings was perfectly legal and within current regulations.

That doesn't address the ethics (or rather, complete lack of them) of using the cheaper, more dangerous materials simply to pretty up social housing so the local millionaires didn't have to look at an eyesore, but I'm not sure there will be any criminal cases as a result of all this.

Just to add - I don't think anyone is suggesting banning these panels outright, or suggesting that they don't have legitimate uses.


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## NickG (Aug 15, 2013)

Well the renovation was procured on a design and build contract, so professional people were paid to select the correct materials. Perfectly legal doesn't really cover it. 'The Law' doesn't need to go into details about what materials should be used where.

What this presents as is Criminal Negligence, there's a clear breach of duty of care and these kinds of cases have lead to criminal convictions on many many occasions. That's the brutal reality in construction, you have a Duty of Care to so many people that you must make sure what you are doing is spot on every time.

From a professional point of view i think it'll be pretty easy to establish that there was a duty of care from the construction companies to the residents of the tower block and that this was breached.

P.s. I wasn't sure, the title was very 'in your face' and as you say the article cannot be accessed without registration!


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## TFP (May 29, 2010)

NickG said:


> The fact that this material was used on such a recent renovation is nothing short of criminal and the ONLY people that i think need to answer to this terrible tragedy are the professionals involved with the build who were paid to know better.


Some one will have to be blamed.

The contractor fitted the panels knowing they were not suitable for a tall building according to the makers instructions.

But maybe UK building regs allow it?

This austerity thing has been going on too long now, and I'm convinced this has all come about by a council trying to save money because their budget has been continually cut.


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## gily (Apr 28, 2017)

Speaking to my dad who works for a cladding company .. and apparently they did not use fire proof paint on the cladding which didn't help .. I'm not sure how true this is, but seems to me that would of been common sense to use ..

wait ....common sense vs cost ! ah right I see what they did


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## NickG (Aug 15, 2013)

TFP said:


> NickG said:
> 
> 
> > The fact that this material was used on such a recent renovation is nothing short of criminal and the ONLY people that i think need to answer to this terrible tragedy are the professionals involved with the build who were paid to know better.
> ...


It honestly doesn't matter if building regs allow it or not, there's more then enough evidence against using these at height and there are alternative products (I.e. fire rated panels) that it would be "Reasonably Practicable" to use in this situation. Reasonably Practicable being a key phrase here;


> doing what is reasonably able to be done to ensure the health and safety of others)


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## NickG (Aug 15, 2013)

gily said:


> Speaking to my dad who works for a cladding company .. and apparently they did not use fire proof paint on the cladding which didn't help .. I'm not sure how true this is, but seems to me that would of been common sense to use ..
> 
> wait ....common sense vs cost ! ah right I see what they did


This type of cladding isn't painted, so probably false information being spread by the media. :roll:


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## TFP (May 29, 2010)

I just hope ALL of the people involved in the decisions get prosecuted.

If it was a cost cutting exercise then it leads right to the top, the people cutting the councils budgets for the last few years.


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## NickG (Aug 15, 2013)

TFP said:


> I just hope ALL of the people involved in the decisions get prosecuted.
> 
> If it was a cost cutting exercise then it leads right to the top, the people cutting the councils budgets for the last few years.


Couldn't agree more, what's so annoying is the number of people that will have effectively signed this off as ok.


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## Spandex (Feb 20, 2009)

NickG said:


> It honestly doesn't matter if building regs allow it or not, there's more then enough evidence against using these at height and there are alternative products (I.e. fire rated panels) that it would be "Reasonably Practicable" to use in this situation. Reasonably Practicable being a key phrase here;
> 
> 
> > doing what is reasonably able to be done to ensure the health and safety of others)


Is that true? Whilst there is evidence against using these panels above certain heights, the regulations differ from country to country and it would seem to me that the chances of prosecuting based on what is considered safe in another country would be slim. The panels meet UK building regs for high rise residential buildings, they were (in theory) approved before install, they were (in theory) installed according to UK regs and they were signed off on this basis.

I'm doing a bit of work in my kitchen at home, where there's a steel beam in the ceiling supporting a load bearing wall above. The regs say I have to cover it in 2 layers of standard 12.5mm plasterboard, or 1 layer of 12.5mm fire resistant plasterboard. This, I assume, is to give X (minimum) amount of protection to the steel in a fire, allowing time to evacuate. Now, given the ceiling height, it is reasonably practical for me to add 5 layers of fire resistant PB instead of 1 - does that mean I should do so to avoid potential future prosecution?

Please don't see this as me defending the companies involved in this refurb - I think morally and ethically this whole thing stinks. But I just don't see how a criminal prosecution could proceed (obviously based on some assumptions that they did what they agreed with BC. That might change).


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## Shug750S (Feb 6, 2012)

gily said:


> Speaking to my dad who works for a cladding company .. and apparently they did not use fire proof paint on the cladding which didn't help .. I'm not sure how true this is, but seems to me that would of been common sense to use ..
> 
> wait ....common sense vs cost ! ah right I see what they did


These panels are not painted, so bit worried if he works for a cladding company and said that..

Issues well known within fire industry. All about panels being tested in small scale tests for surface spread of flame, to get through building regs approvals. Problem is in the real world or in large scale tests the panels delaminate and the internal combustible core is exposed, melts and the fire spreads rapidly.

Numerous recent fires in Dubai and Oz, all linked to cladding systems. Only difference those buildings were sprinkler protected, so fire was mainly external and safe egress was maintained.

Speculation here (one of many rumours at present) is fire started inside one flat and quickly spread. If true, the Sprinklers (if fitted) would have contained / controlled the original incident in room of origin, and would have been a single appliance call out to make sure all was out. No drama

I have worked internationally as a risk engineer for some of the largest insurers and brokers for 25+ years. Been involved in these discussions for 20 odd years. Refrained from any comment until now on any forum as would rather wait for full data to be available for analysis.


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## NickG (Aug 15, 2013)

Regards your kitchen, you have read up and know what you should use, if you meet those expectations then you are absolutely fine. The way a Breach of Duty of Care is established is by considering what a reasonable person would have done in the position of the person owing the duty of care, not what a perfect person would have done.

In the case of the fire;


> It should be noted that the standard of care may be deemed to be higher if the person is a professional or holds themselves out as possessing a certain level of special skill. In that situation, the standard required would be what that type of person would be reasonably expected to have.


From this what i am trying to present is, you have read the regulations and not being an expert, by following these you are deemed to have done the correct thing to the best of your ability. The cladding contractors would fall under the title of a professional person and particularly an expert in cladding, therefore they are expected to go over and above the general building regulations and ensure what they are providing meets the needs of the building (They can't hide behind a regulations loophole basically!).

Remember this was a D&B (Design and Build) procurement, therefore Professional Indemnity insurance will be in place and this will state that any design work must be completed by a competent professional expert with knowledge in the area of design. It's absolutely no secret within the cladding industry that this stuff is highly inflammable, this isn't a new occurrence within the industry and that is why other products exist.

It's perhaps worth pointing out that i'm in a weird position being a qualified Surveyor and (Allegedly) educated to a high standard in construction law (Although not often applied these days!) as well as owning a fabrication company who form the same type of panels involved in this incident.


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## ashfinlayson (Oct 26, 2013)

The trouble is the council won't take ownership because they just offed the work to a procurement company that said they could do the job for the price regardless of how low the price was. The procurement company will have subbed all the work out to various LTD contractors offloading their obligations so no single entity will have known enough about the project to be held responsible for the failures. Just can't see that anyone will be prosecuted for the cockups, a few people will resign but that'll be that.


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## Spandex (Feb 20, 2009)

Looking into it a bit, it seems a legal duty of care test has 3 stages:

1. Harm must be a "reasonably foreseeable" result of the defendant's conduct;
2. A relationship of "proximity" must exist between the defendant and the claimant;
3. It must be "fair, just and reasonable" to impose liability.

I think 2 and 3 are a given, but for 1 I'm not so sure. I just don't think a court would say the definition of 'reasonable' would go beyond meeting all applicable regulations. Is it reasonable for a contractor to foresee that the building regulations were inadequate, where the regulators themselves haven't seen that?


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## Nyxx (May 1, 2012)

ashfinlayson said:


> The trouble is the council won't take ownership because they just offed the work to a procurement company that said they could do the job for the price regardless of how low the price was.


The problem when dealing with local council I have found and I know people that ever sit on them, is "they class money being spent, is our money" that's right, but and it's a big but, 9 times out of 10 they go with the lowest bid for the work being tendered for. 
So if the tender from the company that did the work came in savings the council let's say £30,000 under everyone else, to the council way of looking at it, they saved the tax payer £30,000. It's also does not matter if it's labour or conservative they are all the same. A company could go to great lengths to explain their using the best methods etc but as long as the lowest bid meets the basic standards it's down to money nothing else.

Who ever gets the blame in the end will be interesting. If the cladding meets uk building standards then who knows where this will go. If it did not then they should rot in hell.


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## NickG (Aug 15, 2013)

Spandex said:


> I think 2 and 3 are a given, but for 1 I'm not so sure. I just don't think a court would say the definition of 'reasonable' would go beyond meeting all applicable regulations. Is it reasonable for a contractor to foresee that the building regulations were inadequate, where the regulators themselves haven't seen that?


Absolutely! From my knowledge of dealings with the main UK ACM suppliers, they aren't shy about stating which of their products should be used in which scenarios, this and given the highly publicised incidents around the world previously (Dubai & Aus), means that an expert in ACM cladding would and should know that the product used is not suitable.

I've also been having a look into building regulations to bring myself up to speed and there are regulations regarding the spread of fire, for external walls;



> External fire spread
> B4. (1)
> The external walls of the building shall adequately
> resist the spread of fire over the walls and from one building
> ...


_Link to building regs if interested;_
http://www.plumis.co.uk/BR_PDF_ADB1_2006.pdf

Now if a building is under 18m in height then this regulation doesn't apply. Over 18m if the material used is A1 or A2 fire rated it is deemed to automatically be fit for purpose, if the material does not meet the criteria (PE core material is B rated and therefore not compliant automatically) then a much more in depth process is required, involving desktop studies and fire engineering.

Now as all the major manufacturers offer a product that they support as suitable for over 18m it seems very unlikely to me (Although not impossible) that they would support a desktop study for their 'inferior' product. These studies are also very very expensive, so i again doubt that anyone would spend the money on completing that exercise over the £3/m2 cost for a fire rated product.

So back on the point, in actual fact the building regulations are adequate and, unless the contractor completed what would be a very unlikely study into the use of the PE core material, the case for Negligence is very strong.


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## Spandex (Feb 20, 2009)

You seem to be arguing that the panels didn't meet BC regs for that height building - if that's the case then I completely agree that a criminal prosecution isn't far away. However, everyone involved so far has said that the materials used met all relevant regulations and the focus seems to be on the inadequacy of regs themselves rather than a breach by the contractors.

Incidentally, this makes for interesting reading:

http://www.impact-solutions.co.uk/pe-cl ... -all-mean/

There's a panorama documentary on tonight that i think investigates a lot of what we're discussing, so maybe that will shed some light.


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## bobclive22 (Apr 5, 2010)

*Booker: Grenfell - the EU dimension*

This is worth a read, you can come to your own conclusions regarding this piece.

http://www.eureferendum.com/blogview.aspx?blogno=86512

This is the link needing registration.

http://www.cdu.urbanisme.developpement- ... 01a27d.pdf


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## NickG (Aug 15, 2013)

I'll be honest here, I read about 2 paragraphs of what seemed to be nonsense then got bored.

IF the jist of that piece is genuinely blaming the EU for using the cladding because of energy efficiency standards then the author is very uneducated. This system is a rainscreen cladding, which means the system works by having a 50mm ventilated air cavity between cladding and insulation. Due to this the cladding offer no thermal performance to the building, it could be made from cheese as far as energy efficiency is concerned.

If that's not what the article is saying then I apologise, but have no idea, but if you've happened to read it all then a quick summary would be appreciated as it's f***ing long :lol:


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## NickG (Aug 15, 2013)

Spandex said:


> You seem to be arguing that the panels didn't meet BC regs for that height building - if that's the case then I completely agree that a criminal prosecution isn't far away. However, everyone involved so far has said that the materials used met all relevant regulations and the focus seems to be on the inadequacy of regs themselves rather than a breach by the contractors.
> 
> Incidentally, this makes for interesting reading:
> 
> ...


How was the panorama episode Spandex, worth a watch?


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## Spandex (Feb 20, 2009)

NickG said:


> How was the panorama episode Spandex, worth a watch?


Well, it was interesting to hear some of the first hand accounts, but there was very little in there that wasn't already in the news. They didn't really discuss the cladding details at all.

Later on Newsnight though, one of the journalists did say that it now looks like the cladding didn't meet the regs. Not sure why that's not all over the news though.


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## ProjectMick (Sep 29, 2015)

Spandex said:


> Later on Newsnight though, one of the journalists did say that it now looks like the cladding didn't meet the regs. Not sure why that's not all over the news though.


If that is true then anyone involved in getting that signed off should be prosecuted. Architects, council members, contractors whoever.

Also, surely sprinkler systems should now be part of any refurbishment over a certain number of floors. That would have gone a long way to slowing the spread of the fire.


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## Spandex (Feb 20, 2009)

bobclive22 said:


> This is worth a read, you can come to your own conclusions regarding this piece.
> 
> http://www.eureferendum.com/blogview.aspx?blogno=86512


So, the upshot is that we voluntarily chose to implement a European standard that was no less safe than our existing national standard and so now we should jump up and down blaming the EU for that?

And to top it off, the EU aren't forcing us to stick this stuff on old buildings and they're not stopping us from using less flammable stuff instead. Does that cover everything in the article?

Your desperation really does know no bounds Bob. Go back to the EU thread if you want to discuss it.


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## NickG (Aug 15, 2013)

Spandex said:


> Later on Newsnight though, one of the journalists did say that it now looks like the cladding didn't meet the regs. Not sure why that's not all over the news though.


From my research into it, using my own interpretation of building regulations, PE cladding is not acceptable for use above 18m.



ProjectMick said:


> If that is true then anyone involved in getting that signed off should be prosecuted. Architects, council members, contractors whoever.


Absolutely, too many people paid to know a lot better then that.


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## bobclive22 (Apr 5, 2010)

> So, the upshot is that we voluntarily chose to implement a European standard that was no less safe than our existing national standard and so now we should jump up and down blaming the EU for that?
> 
> And to top it off, the EU aren't forcing us to stick this stuff on old buildings and they're not stopping us from using less flammable stuff instead. Does that cover everything in the article?
> 
> Your desperation really does know no bounds Bob. Go back to the EU thread if you want to discuss it.


I thought the point of the article was that counties within the EU cannot change their own regulations without first gaining permission from the EU, no need to attack me Spandex.


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## bobclive22 (Apr 5, 2010)

> From my research into it, using my own interpretation of building regulations, PE cladding is not acceptable for use above 18m.


I might appear that it was the aluminium sheet that was tested and complied with UK building regs not what was stuck to it, that`s probably why Hamond is the only one that has stated the cladding was banned.


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## NickG (Aug 15, 2013)

bobclive22 said:


> > From my research into it, using my own interpretation of building regulations, PE cladding is not acceptable for use above 18m.
> 
> 
> I might appear that it was the aluminium sheet that was tested and complied with UK building regs not what was stuck to it, that`s probably why Hamond is the only one that has stated the cladding was banned.


Hamond has spoken out of context, he's right in what he's said to an extent, it is banned, on buildings over 18m... technically.

I don't think the aluminium sheet has been tested alone, as it wouldn't achieve anything by doing so, thee tests are too expensive to be completing for no reason!


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## bobclive22 (Apr 5, 2010)

> And to top it off, the EU aren't forcing us to stick this stuff on old buildings and they're not stopping us from using less flammable stuff instead. Does that cover everything in the article?


I thought the *EU was all about conformity*, it appears Frances building regs must be similar to ours and should conform to the same EU directive.
Mermoz Tower fire, Roubaix, France 2012.


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## NickG (Aug 15, 2013)

Let's nip this in the bud, there are no standards that are forcing the use of any particular product on any building, that's such a ridiculous thing to imply.


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## Spandex (Feb 20, 2009)

bobclive22 said:


> I thought the point of the article was that counties within the EU cannot change their own regulations without first gaining permission from the EU, no need to attack me Spandex.


If that was the case, how can Germany have different (stricter) regulations? The article states that members have the choice to use the European standard, or to use their own. We *chose* to use the European one voluntarily, although it made no difference because it was no less strict than the national standard it replaced. Once you're using the European standard, you obviously can't just change it, because other countries may be using it too.

And by the way, it seems they're only discussing *material standards*, not the actual approved use of the products. Saying that a certain type of product has to meet a certain spec is one thing - it's quite another to say where that product is allowed to be used. It's up to us whether or not we insist on FR rated panels above 18m. Or even if we allow external insulated cladding at all.

This is all just desperately clutching at a tragedy, trying to use it to prove a non-existent point about the EU. Being in the EU didn't cause this, and being out of the EU wouldn't have prevented it.


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## Stiff (Jun 15, 2015)

Spandex said:


> This is all just desperately clutching at a tragedy, trying to use it to prove a non-existent point about the EU. Being in the EU didn't cause this, and being out of the EU wouldn't have prevented it.


Exactly this ^

Bob, whilst you may have the odd valid point here and there in various threads I think we would all do well to listen to NickG in this particular one. He seems to know *exactly* what he's on about and is much more of an expert in this field than we are.


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## Nyxx (May 1, 2012)

Stiff said:


> Spandex said:
> 
> 
> > This is all just desperately clutching at a tragedy, trying to use it to prove a non-existent point about the EU. Being in the EU didn't cause this, and being out of the EU wouldn't have prevented it.
> ...


Have to agree.


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## Shug750S (Feb 6, 2012)

NickG said:


> Let's nip this in the bud, there are no standards that are forcing the use of any particular product on any building, that's such a ridiculous thing to imply.


+1

Been an insurance risk engineer for years, on industrial not residential, and worked on some of the tallest buidings in the world in Asia and Middle East and we always have same debate with architects and developers who want to use minimum standard products (that comply with building regs). We always push for products that we know don't add to the combustible load. Tested in large scale fire tests, not small scale or surface spread of flame, and definitely not EPS or PE insulation.

End of the day if they want cover from us they use the better products. If not unfortunately always another insurer out there who eyes up the premium and gives cover.

Not sure if Bob will have studies to prove me wrong though...


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## John-H (Jul 13, 2005)

NickG said:


> I'll be honest here, I read about 2 paragraphs of what seemed to be nonsense then got bored.
> 
> IF the jist of that piece is genuinely blaming the EU for using the cladding because of energy efficiency standards then the author is very uneducated. This system is a rainscreen cladding, which means the system works by having a 50mm ventilated air cavity between cladding and insulation. Due to this the cladding offer no thermal performance to the building, it could be made from cheese as far as energy efficiency is concerned.
> 
> If that's not what the article is saying then I apologise, but have no idea, but if you've happened to read it all then a quick summary would be appreciated as it's f***ing long :lol:


Bob, you didn't start this thread to have a pop at the EU did you?

Nick, a colleague at work said something about the DIN standards being applied in Germany would have given a lesser fire rating to these panels than the BS regulations due to the way the flame test is applied to the edge in the former and the face in the later. There was also something about the edge gap - where a flame could get a hold of the edge. Also true what you say about the rear gap - it would allow flow and therefore would not be a good insulator - more a wind break.


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## NickG (Aug 15, 2013)

John-H said:


> NickG said:
> 
> 
> > I'll be honest here, I read about 2 paragraphs of what seemed to be nonsense then got bored.
> ...


Hi John, yeah I've seen a few different testing standards and your absolutely right, a test rig applying flame to the face of 1 panel will yield an entirely different result to a flame targeted at the edge of a panel. It's almost a pointless test applying flame to a panel face, as in the real world these conditions are virtually non-existent.

I like the use of ASTM E84 ratings, as I believe it replicates a much closer to real world scenario (although still not perfect!)






When you compare how PE core material performs next to FR core material, it really highlights the PE panel's failings in this test:


_this example is Vitrabond, a material I frequently use currently, however this is no different to reynobonds offering_

What you will find is most products have been tested using each countries various standards, therefore specifiers should be using ALL of the available data when considering a product!


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## NickG (Aug 15, 2013)

Shug750S said:


> NickG said:
> 
> 
> > Let's nip this in the bud, there are no standards that are forcing the use of any particular product on any building, that's such a ridiculous thing to imply.
> ...


Presumably in a scenario such as this then, you'd be pushing for the Non-combustible offerings, rather then even the FR core products? (I know I would like to see these non-combustible ACM panels used more frequently on high rise buildings!)


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## Shug750S (Feb 6, 2012)

NickG said:


> Shug750S said:
> 
> 
> > NickG said:
> ...


Non combustible every time. Was involved in the LPCB facade testing back in the mid 90s and learnt a lot there.

But not just panels, the risk is rated based on overall construction, compartmentation, fire stopping of ducts risers and at each floor edge, passive and active fire protections, dry risers and in situ hoses, wet risers as applicable, pressurised escape stairs, etc. etc. We look at the whole COPE (Construction, Occupancy, Protection, Exposure) including Nat Cat.

Had a few interesting meetings at FIREX in docklands today. Overall opinion was nothing new, same arguments been going on for years.


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## bobclive22 (Apr 5, 2010)

http://www.arconic.com/aap/europe/pdf/O ... 012017.pdf

it would appear the manufacturers were aware the cladding was a fire hazard especially over 30 meters in height, they knew what building it was scheduled to be installed on and obviously it`s hight as per emails between installer and supplier but supplied it anyway.

Building inspectorate surely must have done some minimal research on the claddings acceptability, ie at least read Arconic`s brochure link above but passed it anyway.

It now appears Iconic have stopped supplying this cladding for any structures above 30 meters high anywhere in the world, bit late to take a moral stance.


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## NickG (Aug 15, 2013)

The thing is, these large ACM manufacturers very often have no idea what building they are to be used on. Bearing in mind most of the sales are through distributors, who sell to fabricators, who make the panels and sell them onto installers... there's 3 different companies between the manufacturer and the Contractor on-site.

I agree that more needs to be done to educate the industry on the choice of panel, but I think it's very hard to put blame on the manufacturer for where their products end up (Albeit there are 'apparently' emails discussing this particular project).

Projections being made on when cladding can be removed and replaced from affected blocks currently are beyond laughable, the entire construction industry is beyond stretched as it is, so fitting in 600 facade replacement projects in 2 years is just ludicrous!

On top of that I'd put money that the sensible option won't be taken for the majority of replacements, i.e. The cheapest and most effective solution is for a straight swap of panels for identical size and finish but using non-combustible or fire rated cores. This would allow the support structure and entire build-up to remain unaltered and prove much more cost effective then a complete strip and replace job... unfortunately I fear media hype will cause too many ultimate decision makers to take the wrong decision and refuse to use ACM entirely (even non-combustible).


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## Von Twinzig (Feb 10, 2014)

Read all this. Typical forum debate. Some knowledge, but also a lot of conjecture. I wrote a pile of technical stuff in response then deleted it as it was turning into an expert witness statement.

I've worked on high rise rainscreen cladding for nearly 30 years. Here's my 2 cents.

Tower block fires post refurb have been going on since the principles of insulated rainscreen cladding were first developed. My first experience being Knowsley Heights in Manchester. After each one you will hear the phrase "Lessons will be learned" and indeed they often are, right up to when the next one takes place.

Anyway, reading this article from the AJ will give some insight and perspective......

https://www.architectsjournal.co.uk/hom ... 12.article

And this one's pretty useful too..http://www.probyn-miers.com/perspective ... om-the-uk/

Couple of facts...the EU reaction to fire standard is 13501-1, It's tougher than BS 476 where the best you can achieve for combustiblity is Class 0 that equates to a B classification under the EU test. Both insulation and cladding on Grenfell had this rating and as such were permitted to be used above 18m (this being the EU cut off point for combustible materials in facade construction). By comparison my companies cladding products that I test are A2, which not only requires the product to pass a 30 min flame test, but also each layer must also pass a further test - ISO1716 if you're interested. All cladding is not created equal.

Hold this thought....the insulation, the supporting bracket and rail system and the cladding product itself all contained aluminium. Aluminium of this grade melts at around 660 deg C. Flashover temps (when the windows blow out) exceed 1000deg C within in a few seconds. Typically using an A1 rated insulation like Rockwool protects the brackets from heat providing the frame with an element of protection, but that wouldn't have been the case at Grenfell.

Last week I was in N.France checking out some huge social housing refurbs we're working on. The French testing and certification dept (CSTB) mandates the spec for the facade...Insulation? That'll be Class A1, in our case Isover FG. Aluminium frame? Oh no, that's steel brackets and rails. And the facade...well that's our A2 cement panel. But not satisfied with that the spec also calls for steel profile fire breaks on every other floor slab and steel angles on each corner of the building to stop any fire travelling round the block. The people writing our regs should take a trip across the channel they might just learn something.





































VT


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## John-H (Jul 13, 2005)

Guys,

I get the impression our standards are lagging behind the EU norm, well in respect of DIN standards at least. I realise standards vary form country to country too for climatic reasons so there is not a level base.

What I would appreciate an expert opinion on, not being one myself, is the somewhat confusing statements from the UK government saying that all the cladding samples submitted have failed building regulations, and yet the suppliers previously said the cladding met building regulations.

Are the government applying a different standard to make them all fail?

What standard do the building regulations actually require?

Are the standards so wishy washy that there is room for huge interpretation?


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## NickG (Aug 15, 2013)

Yep they certainly do it better over there!

What's frustrating is that it's common knowledge just how bad the PE core material is regarding fire, so how does anyone justify using it over FR products even if they think they have found a 'loophole' in building regulations?

I don't believe there are loopholes, as the general requirement is;



> External fire spread
> B4. (1) The external walls of the building shall adequately
> resist the spread of fire over the walls and from one building
> to another, having regard to the height, use and position of
> the building.


I personally think it's blatantly obvious that PE material does not meet the main requirement of Section B4 - External Fire Spread.


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## John-H (Jul 13, 2005)

Well if that's the case how has the interpretation to a lesser standard, that doesn't meet the broader interpretation, got away with it for so long?

Is there a lack of checking? Lack of inspection? The former points leading to a "you can get away with it" attitude?

Have we deregulated the requirements of our inspectorate to the point of ineffectiveness?


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## Spandex (Feb 20, 2009)

John-H said:


> somewhat confusing statements from the UK government saying that all the cladding samples submitted have failed building regulations, and yet the suppliers previously said the cladding met building regulations.


There are two separate things here. The BS and EN specs relate to the actual materials used. The building regs relate to how and where those materials are used.

So the government testing isn't for compliance with building regs as such (although it could show a failure to meet the regs if it shows the wrong material was used). The real problem though, is that the government hasn't actually said what they're testing.


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## Spandex (Feb 20, 2009)

NickG said:


> I don't believe there are loopholes, as the general requirement is;
> 
> 
> 
> ...


Is that the only rule? That seems like potential loophole after potential loophole to me. What's the legal definition of 'adequately'? What's the legal definition of 'having regard to'?

I have had relatively minimal interaction with BC, but my experience has been that the regs are fairly vague (as above) and there is a fair degree of interpretation applied to decisions.


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## bobclive22 (Apr 5, 2010)

> *Yep they certainly do it better over there!*


I believe France is over there, fire was in 2013 I believe.


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## NickG (Aug 15, 2013)

bobclive22 said:


> > *Yep they certainly do it better over there!*
> 
> 
> I believe France is over there, fire was in 2013 I believe.


Doesn't give any info on when it was built though does it! :roll:


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## Von Twinzig (Feb 10, 2014)

John-H said:


> Guys,
> 
> I get the impression our standards are lagging behind the EU norm, well in respect of DIN standards at least. I realise standards vary form country to country too for climatic reasons so there is not a level base.
> 
> ...


John, the cladding and insulation used at Grenfell were both Euroclass B and therefore complied with the regs. However, Class B is not non-combustible. Here's the description...."Class B products will not lead to a flashover situation, however they will contribute to the fully developed fire;" In other words they are hard to ignite, but once the fire has developed they are likely to ignite and fuel the fire.

I suspect what the government spokesperson is saying is that the tested samples have been found to "not be non-combustible." The words I use here are specific. I'm not saying they _are_ combustible, just that they are not non-combustible as defined in the test standard. Tricky eh!

What you have to remember is that the external envelope should be designed in an holistic way. If you have correctly designed and installed fire barriers and attention is paid to preventing the fire reentering the building through the windows then the fire will be contained and remain outside, but if there has been no provision or the barriers are compromised in some way then you have a problem.

Ever watched replacement windows being installed? They will have generally been made undersize so they fit the opening, then the guys wedge them in place with plastic packers, drill and screw them through the frame into the structure before filling the void between the fame and opening with PU expanding foam. I have no clue how the refurb here was done, but looking at they way the fire went up, down, left, right, and throughout the tower, gutting it, I'd be looking at the integrity of the whole structure not just focussing on the cladding.

VT


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## Von Twinzig (Feb 10, 2014)

bobclive22 said:


> > *Yep they certainly do it better over there!*
> 
> 
> I believe France is over there, fire was in 2013 I believe.


I know this fire.Same basic product as used at Grenfell.

Two takeaways: the wind is from left to right so the fire can't easily move to the left. See the pinky red panels? They are fibre cement, non-combustible so the fire was contained. After this fire the French regulations changed.

VT


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## Von Twinzig (Feb 10, 2014)

A little more light reading for you...http://www.rockwool.co.uk/globalassets/ ... or-web.pdf

This document shows how, by designing in an holistic way, you can use Class B rated products above 18m.

VT


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## NickG (Aug 15, 2013)

Von Twinzig said:


> A little more light reading for you...http://www.rockwool.co.uk/globalassets/ ... or-web.pdf
> 
> This document shows how, by designing in an holistic way, you can use Class B rated products above 18m.
> 
> VT


However in practice this is impractical, expensive, time consuming and still not guaranteed to get passed by some NHBC officers (for example)... I've been there previously. Unless you work for an enormous Envelope contractor (Think Prater, Lakesemere), it simply isn't an option.

The better option would be for regulations to demand the use of non-combustible products above 18m fullstop, safe in the knowledge that the envelope is fit for purpose entirely, not down to the opinion of what one person decides is an appropriate risk and not provide another bloody loophole that the big forms can exploit.

There's plenty of A2 rated facade finishes out there, why are we still dicking about trying to use products that have much more suitable alternatives?!


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## John-H (Jul 13, 2005)

I take the point that a holistic approach to the design could employ materials safely that may be dangerous if applied without care but I presume that's covered (or should be covered) by building regulations and may even be documented by the manufacturer of the materials by way of recommendation for safe use thereby imposing a duty of care that could be evidence for negligence if ignored.

The government are applying tests to samples - presumably single panels or pieces and declaring them a "failure". A failure of what exactly? As Spandex points out, the test they are applying is unclear. This is at the heart of my question.

When the samples are tested, do they take into account the position, mounting methods and other materials in the vicinity of where it was taken in order to assess building standards and the holistic design of the facade regarding fire safety? Or are they merely applying a particular material flammability standard?

Are they presuming the worst construction methods with no consideration of the whole which then requires a non flammable cladding material, leading them to perhaps incorrectly declare the sample a failure?

Is this where the contradiction lies? This leads to questions: (a) Have all the builders/designers/specifiers been negligent? (b) Are the government applying the tests incorrectly or perhaps creatively to a standard that is higher but not required in current regulations? Leading to (c) are our standards not up to the job?


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## Spandex (Feb 20, 2009)

I don't think there is any reason to believe the material standards aren't good enough - there are a whole range of specifications out there, which results in a whole range of products being developed and offered for sale. Some of those products aren't fire resistant and that's fine because they're not supposed to be - they meet the relevant spec for non fire resistant panels and they're ok to use in specific designs.

So, we're left with the regulations which determine which of those products is approved to be used where, and how. These I imagine will need to be changed either in what they specify, or in how strictly they're enforced, or both.

But back to the government tests, I suspect (and this is just a guess really) that they're simply testing if the panels are fire resistant. That's the only thing I can think of that would explain the 100% failure rate. That would make the whole exercise a little misleading though, if fire resistant materials aren't actually a regulated requirement for this application.

The other thing that makes me think they're testing in isolation without regard to the building regs is that they're not removing lots of cladding to see how the system was designed/implemented and they're not taking the panels from above a certain height. They're just grabbing a low down single panel. I just can't see what this testing will really prove.


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## Nyxx (May 1, 2012)

Spandex said:


> I don't think there is any reason to believe the material standards aren't good enough - there are a whole range of specifications out there, which results in a whole range of products being developed and offered for sale. Some of those products aren't fire resistant and that's fine because they're not supposed to be - they meet the relevant spec for non fire resistant panels and they're ok to use in specific designs.
> 
> So, we're left with the regulations which determine which of those products is approved to be used where, and how. These I imagine will need to be changed either in what they specify, or in how strictly they're enforced, or both.
> 
> ...


Agree, 
(_Damm thats the 2nd time I've done that!_  :wink: )


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## Von Twinzig (Feb 10, 2014)

They aren't doing the construction test as that looks like this....



 and cost me 30 grand a pop to do.

The thing to remember about fire testing is that you select, build, test and get a report on your proposed construction. If you then change any element in the test it renders your results null and void. You could easily get thorough £250k going through some basic permutations.

Interesting thought. A number of years ago we did some full scale testing in one of the hangers at Cardington using a fibre cement panel, ally rail system and Rockwool fixed back to the structure with the plastic mushroom fixings. As the fire travelled up the cavity behind the cladding it melted the insulation restraints, the Rockwool now unrestrained then fell down the cavity and put the fire out! A completely unexpected, but welcome result.

Solving this is easy. An A1 insulation fixed behind a steel frame with an A2 cladding product. Fire breaks on the floor slabs and building corners.Job done. You don't even need to test is as there's nothing to burn. Trouble is your thermal calculations go out the window as you now have hundreds of thermal shorts to deal with via thermal break systems. Life's not easy.

VT


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## Spandex (Feb 20, 2009)

Given that this was a refurb of an existing structure, is there any requirement to meet current thermal regs? My understanding of domestic regulations is that, for refurbs of existing buildings, as long as the work you carry out doesn't make the building less compliant than it was before you started, it's all good.

That's based on me, as a civvie, scanning the regs to make sure I'm not going to upset BC when I work on my extension, so might be wrong and might be completely irrelevant for a building like Grenfell.


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## Von Twinzig (Feb 10, 2014)

There are still U-value targets for R&R on residential buildings. And your extension will have to comply with building regs and that includes thermal performance, so you will have to meet the values for domestic extensions. Not as high as new build, but higher than a refurb requires.

VT


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## Spandex (Feb 20, 2009)

Von Twinzig said:


> There are still U-value targets for R&R on residential buildings. And your extension will have to comply with building regs and that includes thermal performance, so you will have to meet the values for domestic extensions. Not as high as new build, but higher than a refurb requires.
> 
> VT


Fortunately, I've stuck to regs for insulation on the (extremely small) extension anyway, but it does amuse me that I now have a tiny section of my house that's full of insulation and the rest of the old victorian mid-terrace is still as leaky as a sieve.


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## bobclive22 (Apr 5, 2010)

> Fortunately, I've stuck to regs for insulation on the (extremely small) extension anyway, but it does amuse me that I now have a tiny section of my house that's full of insulation and the rest of the old victorian mid-terrace is still as leaky as a sieve.


Try this, It should keep you nice and warm, not sure whether it is fireproof though, it doesn`t say.

https://www.thegreenage.co.uk/tech/exte ... nsulation/


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## Spandex (Feb 20, 2009)

bobclive22 said:


> Try this, It should keep you nice and warm, not sure whether it is fireproof though, it doesn`t say.
> 
> https://www.thegreenage.co.uk/tech/exte ... nsulation/


Thanks, but:

1) I prefer the look of bricks on an old house.
b) It might look a bit odd in a terrace if my house in the middle stuck out 100mm compared to the ones either side.
iii) Being mid-terrace in a row of houses with walls so thin you can hear your neighbours breathing, has it's benefits. I can let them heat my house for me.


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## bobclive22 (Apr 5, 2010)

This is an interesting read,

Fire regulations: What needs to change

http://www.bdonline.co.uk/news/analysis ... 88.article

(needs registration) full PDF article below.

Hope attachment works.


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## NickG (Aug 15, 2013)

Had an interesting meeting with Vitrabond today and a couple of things were confirmed to me:

1) the government testing currently underway is testing whether the product is combustible or not, hence every test has failed because it's a pass fail test and even FR product will combust to a very very small extent.

2) works are underway on the majority of these products to switch to non-combustible A2 rated aluminium composite panels (spent this week machining some samples and they look identical but are much lighter which is a bonus!)

3) PE core product is basically expected not to be produced anymore, from any major manufacturer it seems (not a bad thing)

4) NHBC have withdrawn their guideance notes regarding ACM cladding pending a review

5) A lot of insulation products are also under scrutiny, including phenolic based products such as kingspan K15, previously sold as suitable for use over 18m.

6) There's a lot of evidence to suggest that a large number of buildings do not have correct fire barriers etc. To even meet the old expected standards... this is scary!

Change is happening and it is happening fast! It's too late to save the lives lost in this terrible tragedy, but it's not to late to prevent future occurrences.


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## Shug750S (Feb 6, 2012)

I had the same feedback on your point 1.

Are they still testing integrity, insulation etc, as per the LPCB certification, or just applying flame to large scale rigs and see if it's combustible at any time?

makes you wonder why they don't set a FR time, say 120 / 180 / 240 mins and set the bar there?

Problem is even rated panels can have issues if they have edges removed or penetrations not sleeved / sealed. So presumably they will end up with an installation sign-off as well as approved products.


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