Sunday, 18 June 2017

Grenfell Tower

Around 6am, 5am UK time, last Wednesday morning I started watching Grenfell Tower burning. It was clear from the footage that the fire progressed on the outside of the building. "Cladding" I said to my plumber. A bit of digging about found the portfolio pics on the website of Studio E architects, of Tooley Street; they confirmed that an aluminium sandwich panel was specified. The architects have since taken down their website and are keeping a very low profile. Their residential portfolio has also disappeared from their RIBA page. 

It's all about energy efficiency. This was a concrete tower block with inadequate insulation and single glazed steel or aluminium windows. To slash heat loss, new external wall insulation and double glazed windows have been a standard solution since the start of the century, and to that extent no problem. EWI on low rise and domestic buildings usually means dark grey PE or Polyethylene foam in blocks up to 150mm thick stuck and screwed onto the existing facade. On low rise this is then usually rendered to give a 15mm thick crust that stops people poking holes in the foam with their fingers (but useless against woodpeckers, who now prefer making nests in EWI than in trees). 

We've all known for years that PE foam was a fire risk, and it's always therefore been replaced by 120mm - 200mm of mineral wool for higher buildings. However, repeated wet work - layers of render coats - at heights is costly and problematic, with the risk of injury if the adhesive bond between render and rockwool fails and chunks fall off. In place of render on highrise buildings the industry instead uses rainscreen cladding, designed to be fairly but not absolutely waterproof. So a void is left between the cladding and the rockwool to allow some rainwater to drip down and be drained without soaking the EWI. Again, not a problem if the rainscreen cladding is not inflammable and if fire-stopping and drainage at each storey is incorporated. 

What we know from the photographs and news reports is that rockwool was used - correctly - for the insulation but so it seems was the inflammable PE foam - if only in a 5mm thick layer in the middle of an aluminium sandwich for the rainscreen cladding. Suspicions that fire-stopping was left out - which would make drainage behind the facade much cheaper and easier - would explain a chimney effect for the fire spread. 

Now, none of this is specialist construction design and engineering. Just about everyone in construction knows the problems with PE foam - and personally I won't even use it for low rise not just because it burns so easily but because it's completely vapour impermeable and stops buildings from breathing - and just about everyone knows the importance of fire stopping between dwellings. 

When those responsible for the design and execution of these works face the consequences of their errors it will not be enough to claim that since the government hadn't banned one material or another they are in the clear. All of us in positions of responsibility in construction have an absolute duty of care and design teams - CDM, designer, engineer, supervisor, PM, QS - are constituted in such a way as to provide post-hoc evidence of exactly how such decisions were made. You can be sure that since last Wednesday each one of them will have printed out and assembled every email from this job, every periodic report, every meeting, every bit of written evidence and will now each be constructing a narrative that minimises their own culpability. Lawyers will have been briefed. We must now all wait and allow the enquiry to do what it must. 

Grenfell Tower cladding drawing from Studio E architects
   

32 comments:

Anonymous said...

Didn't you hear the results of the public inquiry published this Thursday?

It was all over BBC Radio 4's PM programme in one of the nastiest bits of reporting I had heard for a long time.

Turns out it was someone called Mrs. May. Rather like Little Britain she designed the building, built the building, packed the building with the poor, blocked the fire escapes, blocked the roads, privatised the 999 services, disconnected the 911 service, defunded the fire brigades, moved the water supplies to France and then, didn't even bother to turn up to laugh at the flames because she was too busy instigating war in Northern Ireland with the aid of an extremist minority majority party of rabid nazis! Or it might have been Thatcher.

Sackerson said...

A valuable expert view, Raedwald, thank you.

Anonymous said...

Well if the aim of this upgrade was to keep the residents warm, an exceptional job was done...

Personally, I would like to think that building control types were thinking about customer safety, rather than climate change.

It wouldn't have cost much to install sprinkler systems, get to a fire at source and you put it out.

DeeDee99 said...

Thank you for the detailed explatoon.

I hope that the Enquiry will also investigate whether previous Governments and Ministers failed to implement recommendations from previous enquiries/coroner's reports and themCivil Servants involvement in decision-making.

@ Anonymous: Labour Party politicians have decided that this is all the fault of Mrs May and their activists on the ground and the ones in the BBC and Sky News are pushing the story-line. She's a weakened PM because of the election fiasco and they're determined to bring her down.

terence patrick hewett said...

Mark Steyn:

The Great Fire of a New London:

https://www.steynonline.com/7921/the-great-fire-of-a-new-london

Anonymous said...

Good post Radders.
I don't think you are right about the Rockwool though. Architect's site was back up yesterday when I checked and photos clearly show a rigid foil-faced Kingspan-style rigid PU.

You can also see the progress of the fire in all of the photos and it looks like it progressed up and across in steps and also back DOWN the collumns via molten flaming insulant.

In any case. Even Rockwool slabs have a resin binder that spontaneously combusts when it releases as a gas.
The only 100% option is foamed glass.


And its not about Sprinklers, Fire Plans, Fire Service Cuts etc as they are all about how you deal with the fire AFTER its started.

Choice one - sprinklers everywhere, Grade D interlinked fire alarms and 24/7 security guards on every level but leave the dangerous cladding on?

Choice two - none of that but just remove the cladding?
No brainer really.

The procurement route is the real issue here though (as I'm sensing you probably know).

For 200 years or more the system has been : -
1 Client wants work done
2 Client appoints Architect
3 Architect produces designs. Gets Tenders. Appoints Contractor. Inspects work.

Architects are independent. No commercial conflicts of interest. Trained. Qualified and have indemnity.

Contractors are none of these things.
Contractors traditionally don't like Architects. For good reason.
So, for the last 30 years, Contractors (Surveyors) have worked away and managed to turn the tables.
No longer are they told what to do by some bossy Architect who might affect their profits and make the building cost more.
Contractors now have the ear of the Clients. The Housing Associations.

And so we find ourselves in a position where Clients no longer have an independent professional running their project and keeping commercially-driven Contractors in check.
The Architect is still needed of course, but now he works FOR the Contractor as a sub-contractor.
It doesnt matter who ticks the CDM boxes as 'Principal Designer' or who produces the Warrant drawings. What matters is the power and control. It's no longer with independent professional Architect's acting in the Client interest, it's with GreedyContractor Ltd.


All beautifully dressed-up as the more palatable-sounding Design and Build 'turnkey' one-stop shop from your 'Preferred Bidder' Contractor Consortium in your Community Partnership Framework Agreement.

Now clients may well have a pool of Architects on their 'framework agreement' or their 'hub' or whatever other nonsense name is currently in fashion, but they are novated into the contract. They are not independent and the Contractor now calls the shots. Including substituting whatever materials they see fit.


Restore the old procurement route.
Architects and Clerk Of Works working FOR the client. Free of commercial pressure and with ability to instruct taking-down, rebuilding and just doing what the hell they are told.

Anonymous said...

Anon 10:19 - Are you an Architect? Reads like it. Architects WERE involved, and not only that, they CHOSE the cladding.

Also, at c £10,000,000, this is obviously not subject to huge commercial pressures: it's around £80k per flat for cladding. If energy costs bother you, you can get a lot of electricity for £80k.

A fire can't spread if (a) it was never started, (b) there is no path from the source to the inflammable materials, and (c) no path between the flammable parts.

Anonymous said...

I am yes.
I know they were involved.
They probably did choose the cladding.
But was it a 'Contractor Design' item?
Was it a traditional appointment where they had authority to say no and refuse .
Who was in charge? Contractor or Architect?
Seems there was a previous preferred bidder £1m more expensive and the final contractor obviously found savings to get the job within budget. Say 500sqm cladding saving say £50 is £25,000. It all adds up
So many questions.
Who decided that wrapping a residential tower block in slabs of combustable material was a goid idea?
The original 1970s tower stood fine for half a century and then a year after the council decide to make it look pretty and lower its carbon footprint it burns.
Im being cynical and i dont mean to be, but im sensing the real source of anger here is the 'community' actually dont know who to blame yet. Maybe they just wont work it out and the sprinkler contractors and insurance industry will rub their hands together.

Raedwald said...

Anon - I've been looking at these fire pics; all look like rockwool to me but I could be wrong

https://i.imgur.com/Behh5om.jpg
https://i.imgur.com/Aro3nuj.jpg
https://i.imgur.com/NxsvsYq.jpg

Agree with most of your comments on construction procurement; the way risk is priced has altered a number of power relationships, and the variety of standard form contracts available mean that an architect may be the scheme PM with absolute authority under NEC3, to contractor's gofer under JCT D&B.

I take it you don't think CDM 2015 is much of an answer - nor the HSE proposal to turn their legal guidance into a CoP?

Ed P said...

How many more high-rise buildings in the UK have been made hazardous in this way, due to cost-cutting, contractor corruption or just plain ignorant stupidity? You would hope every resident of these potential bonfires are asking questions about their own blocks.

Demetrius said...

Very interesting and informative article. However, it appears that the government and main media seem to think that it will take years to produce a report. In my blog on Grenfell I suggested that an expert team might need only a short period of time. Reading your article, along with other sources, I along with others have already learned a great deal about what is involved. Another question is how social housing is provided and managed now and what complications arise from this.

The English Physician said...

I think Aluminium is a big issue here.
Aluminium burns fiercely if the fire is hot enough, as we learned when an Exocet his HMS Sheffield in the Falklands. The white heat of those flames suggests to me that more than plastic is burning.
Aluminium powder + oxidant in a plastic matrix is the formula for solid rocket fuel.
Polythene will catch fire with a match. Thin aluminium sheet on burning polythene has oxidant on one side, and a source of heat backed by unburned, heat insulating plastic on the other.
Temperatures increase. When the aluminium starts to burn it generates much more heat and a sort of chain reaction takes hold. Fire spread becomes almost explosive.
The big question is how did this fire start.

Anonymous said...

Radders
I can see how it looks like Rockwool in the 'after' pics you linked but I think that's charred PIR boards.
If you look at the 'before' pics from the Architect's website I'm prety sure that is an (unbranded?) foil face Polyisocyanurate (ISO) board.
Can tell by the ochre coloured core and the neat way it has been sawed on the splay.
Seems to be double layered on the spandrels between windows and single layered on the triangle detail up the structural mullions.

Theres a storey level cavity-barrier stuck on there too but frankly I cant see what good it would do with flaming Reynobond/Alucobond up the outside and PIR up the back.
And I agree that the 2mm aluminium sandwich could be a big part of this. Especially glowing white hot and dripping down to the PIR below.

I read it was (maybe?) a faulty fridge. But it could be someone leaving a frying pan on.
Any kitchen fire is going along the ceiling, out the window and lapping up to the exposed cladding soffit.

http://imgur.com/a/tWjtH

Anonymous said...

On CDM, you'll know that original CDM Regs had the magical new role of CDM Co-ordinator.
A box-ticking exercise able to be carried out by, well pretty much anyone really as there was no qualification required.
A lot of QS practices took it up eagerly as a little something extra but people were soon doing it for £50
There was no 'design function' it was entirely clerical.
Realising the pointlessness of it they evolved it into CDM 2015 - did away with the vague CDMc and rebadged the guy responsible as the 'principal designer'
A recognition in name at least that the creative driver was the guy doing the drawings but still couldnt quite bring themsleves to say 'Architect'.
You're criminally liable if you arent a qualified gas fitter and you so much as look at a gas pipe but your granny can lodge Planning and Building Warrants. Even better if they are subcontracted and controlled by the Contractor.


I can hear it now, the call for 'more regulation'. It's a false sense of security, people assuming that 'someone else' is always looking after them.
If the CDM process wasnt followed then theyll say "oh look what happens when you break the regulations!!" Jail them.
Im sure it was followed. And yet it happened. Because it's very possible that all 'Regulations' were followed and that this is a loophole.
Perhaps someone in the Design Team was actually uneasy abot these boards. Perhaps the guys fixing them werent sure either but hey it passes the 'regulations' and the online CDM Notication to HSE was correctly completed so it must be ok right? Relying on regulations and not personal instinct is not good.
I can legally drive at 60mph on a country lane withing the regulations but it doesnt mean that every bend is safe to take at that speed.

Theres a proliferation of contractor-led 'Hubs' that a large number of public work is being procured through.
Professional fees are completely abysmal for these and then the contractors are incredibly brutal in driving down the fees of design consultants, post award.
Not to mention the disastrous policy of PFI introduced under Labour, we are paying billions to private funders on interest rates that even Wonga would be ashamed to charge, when construction of a new jail costs £80m yet the total repayment by the tax payer over the lifetime of the project is close to £1bn!

Public bodies are genuinely terrified of selecting anyone other than the lowest fee bid in case the press or public attack them for ‘wasting public money’.
Public tenders are often managed by someone with little or no construction or architectural background, a ‘procurement manager’ that can be purchasing cleaning services one day and then asked to procure a design team the next.
They don’t know what the critical issues are or questions that should be asked of a potential bidder. They'll cut and paste European Journal PQQ template.
which ask meaningless procedural information (eg equal opportunity policy, discrimation policy) above project specific issues.
The new standardised PQQ produced under Govt's procurement review has about 110 questions of which only 3 relate to technical proficiency & experience.
Standard practice is to ask for examples of near identical completed projects but no assessment whether they are actually any good. So the same Contracting Consortium and practices produce the same buildings, making the same mistakes.

And if you're 'lucky' enough to get through the PQQ, some hopeless practice (and they're depressing in number) goes and buys the job anyway.
Architecture is broken.
This won't be fixed quickly. I'm certainly curious as to what way it will go.

Anonymous said...

Thanks for the education Raedwald - and the others here. I was listening to an interview broadcast by the BBC yesterday evening, and it was Owen Jones and he was leading a demonstration outside Downing Street. I won't bore you all with the nonsense this child speaks but the very fact that the media wants his opinion on anything is really quite disturbing.

Have they found the Ethiopian yet?

Steve

Raedwald said...

Anon - horrified to say it does look like an unbranded Kingspan-type material in that pic; on the face of it, this can't be used over 18m for inhabited buildings BUT looking at the Kingspan website, they offer a neat guide for getting around the Building Regs - http://www.kingspaninsulation.co.uk/getattachment/dc8cf2c7-5e23-4d9a-9a1f-96bdf571ecdd/Techncial-Bulletin--Routes-to-Compliance--Fire-Saf.aspx

The seemingly unbranded material itself raises many questions - BBA Agrément Certificate? Fire testing / compliance? Case study exemption data using this product? If it was just a cheap knock-off Kingspan clone from Thailand it makes for unbelieveable negligence

Anonymous said...

As the hours pass it looks more like non-compliance. Just heard a government minister on the early evening news say the cladding type used in the Grenfell Tower refurb is not approved for the UK.

Steve

Anonymous said...

I'm here in Michigan bemusedly reading the Daily Mail and am impressed that in less than 24 hours they found their Emmanuel Goldstein in the company that installed the cladding. Over a quarter of the story detailing his £2 million house, his luxury car abd lavish vacations. The mob is well and truly whipped up.

To my mind the ultimate responsibility lies with the owner, but since that seems to be the Council they will prove to be an unsatifactory villain as bureaucrats are past masters at ducking blame. No, the eeebil rich folks are much more satisfying. And the less said about Corbyn being hot to confiscate.... err requisition homes of the local rich the better. Were I PM I would put out an appeal to those owing vacant houses to take in the displaced, thus differentiating myself from Labour's crude envy and theft.

RAC said...

This is just a thought from one with no related knowledge.
I notice that the new window frames had been set out from the original building face in a box like structure, no doubt to bring the finished window flush with the new cladding. Any flame going up inside the cladding would bear directly the underside of those "boxes." Depending on the integrity of the material (sheet alluminium ?) could this have been the entry that allowed the fire into the room interiors.

Thud said...

Top notch post and comments, I too worried about the potential 'knock off' origin of the materials used.

Michael said...

Back in the eighties, I worked with a great company which was trying to get on the cladding ladder for sheds and buildings like this.

The big enemy was Factory Mutual back then, and it took us ages to convince tem they were wrong, and that composite cladding had a decent future, not a disaster.

They lost - we won, and the buildings we created still stand and are still safe.

It's not always about the specification, just the huge insurance companies getting in the way.

Cascadian said...

I have no doubt that an inquiry will eventually identify all errors in the construction of the curtain wall simply because there are so many sources of documents.

What I am less certain about is an enquiry into the actions of the London Fire Brigade, who seem to be culpable due to poor decision making. We have been told that the dry riser system was compromised, the fire alarm inoperative, and the exterior curtain wall heavily compromised when they arrived. All of which would be immediately obvious-yet the order was given to shelter-in-place. With no way to fight the fire internally, too little equipment, that could barely operate above ten stories on the exterior, then evacuation was obviously required, even if it would be hazardous and probably cause some fatalities.

Once again we see that reliance on public services can be lethal.

As yet, I have not heard a logical explanation how an exploding refrigerator could penetrate the exterior wall and start this disastrous fire. Some other source is undoubtedly the cause. Reports of multiple blue flashes seem to indicate an electrical problem, but again that should be limited to the interior space.
And whatever happened to pressurizing stairwells and escape corridors to minimize smoke ingress, which aids evacuation?

Anonymous said...

Radders.
Thinking more about your mention of CDM. I think you could be onto something.
This is a quick and simple fix.
It's actually hard to believe that the Principal Designer currently has no role during construction phase.
It is hard to believe that the regulations spell out the importance of the Designer having to 'take account of health and safety issues arising' from the chosen products and materials, but then provides no way for the Principal Designer to ensure that this is actually done.

Here's my suggestion (for all works other than Domestic Client) : -

CDM 2015
Regulation 10
72. The person who selects products for use in construction is a designer and must take account of health and safety issues arising from their use.
ADD
The Principal Designer must inspect the construction works from time to time at appropriate stages to ensure (as far as is practically possble) that the specified products are being correctly installed.

Liaising with the principal contractor
107 The principal designer must liaise with the principal contractor for the duration
of their appointment . . . .

CHANGE TO
107 The principal designer must liaise with the principal contractor for the duration of the works until Practical Completion.

ADD
If the principal designer’s appointment finishes before the end of the project, the client must immediately appoint another principal designer or stop construction until such time as another principal designer is appointed.

ADD
The Principal Designer must be directly appointed by the Client and not as third party or Sub Contractor.
The Principal Contractor cannot be the Principal Designer.
The Principal Contractor cannot be the Client.

- - -

The Government could have this passed in the House this afternoon they wanted.
Job done.

Anonymous said...

Cascadian,
It seems there are two fires per day in tower blocks in the London area.
For 99% of these, staying-put is the correct advice.
These fires are small and internal and contained in apartments and there would be chaos and possible death by trampling and panic if entire tower blocks were evacuated down stairwells every time someone's frying pan went up.
I think you might be right that in this specific case it should have been very obvious that this wasnt a normal contained apartment fire and that the decision to order everyone out ASAP should have been made immediately if not a lot sooner.
Not fair to prejudge the official investigation though, but you could be right.

Fridges can be nasty. Many possibilities. Ice-maker motors can jam and start fire. The insulation around the fridge is the same foam as the cladding on the building.
Fridge catches fire. Kitchen wallpaper catches fire. Window cracks and breaks and the fire is out and lighting-up the cladding.

Cascadian said...

Anon
In a building with a working fire alarm, an operational dry riser and a dedicated firefighter elevator the shelter-in-place command might make sense as presumably the firefighters could get to the source quickly and effectively. Presumably most of the fires you reference are handled by one fire-fighter and a hand held extinguisher. I am commenting specifically on Grenfell Tower where the LFB had specific knowledge of the danger, had a large exterior fire on their hands that they knew they could not fight, yet blindly followed "procedure". I think it is fair to pre-judge such stupidity.

I am dubious that the scenario you describe of a fridge fire is capable of igniting the exterior cladding, but if you are correct it speaks poorly of european electrical safety, as well as construction.

James Higham said...

Someone then was deliberately culpable.

anon 2 said...

James Higham @ 23:46 --- Very brave of you to say so, sir!

Seamus said...

On another blog I've been trying to explain the difference between the Requirements in Schedule 1 of the English Building Regulations, which are the actual building regulations, and the Approved Documents which are one route to compliance.

Requirement B4 (1) says: 'The external walls of the building shall adequately resist the spread of fire over the walls... '

People have been arguing that if the material is certified as suitable to be marketed in the EEA as a cladding material then it 'complies with the building regulations'. However, it is clear that the cladding system at Grenfell Tower failed self-evidently to comply with Requirement B4 (1).

As you have done, I argued that certification of individual components does not relieve the designer and building control of responsibility to ensure that the final assembly of these components results in a system that is functional and safe.

Design-and-construct contracts marginalise the person that should carry out this function - the architect and the place of the architect has, at best been usurped by the contractor's 'design co-ordinator' or at worst by the naive belief that cobbling together a number of sub-contractors' design and fit packages is the same as designing a building.

CDM is a joke. How can someone who has not designed the building be the 'principal designer'? The F10 form is also a farce. In other EU countries the information that we put up on an A4 piece of paper in a corner of the site hut has to be displayed on a large sign on the perimeter of the site so that the public know who is responsible for the work.

A couple of other points:

It appears from the RB K and C building control website that this work was carried out under a building notice, as for a small kitchen extension, rather than a full plans approval application. The current status of the building notice is 'Completed Not approved' ( https://www.rbkc.gov.uk/bconline/buildingControlDetails.do?activeTab=summary&keyVal=_RBKC_BCAPR_124682 )

It is still not clear what the main insulation material was - Rockwool or Celotex FR5000. The Architects' Journal says it was Celotex FR5000.

Although it's clear that Reynobond PE and Celotex FR5000 both had a Class O spread of flame rating under BS476, we know that the BS476 test excludes the chimney effect. At Grenfell Tower we had a 50mm ventilation cavity that probably acted as a chimney. Did it have cavity barriers? We don't know whether Reynobond PE and Celotex FR5000 also met the additional limited combustibility requirement of Approved Document B Vol 2 paras 12.5 to 12.9 and Table A7.

Judy W. said...
This comment has been removed by the author.
Anonymous said...

A very good post. I'd be interested to know whether the combination of the replacement alluminium windows and the cladding was the reason for the internal (killing) impact of the fire. It's very striking that all the windows have burnt out allowing the flames to get inside the building, intensifying the fire and taking lives.

Anonymous said...

As I read it the original architects specified zinc clad panels, the change to the cheaper PE ones was signed off subsequently by a firm involved in the project management of the cladding installation, IBI Taylor Young. Anyone know more?

Anonymous said...

what happened on the grenfell tower construction site , the u.k health and safety executive on site regulations and site checks done , very very strict about what building material can be used on the construction site . most have to comply with the british standard Institution, some must have know there where sub standard materials