The Pompey Chimes Forum

On behalf of my profession I am so, so sorry.
In the 60's and 70's we architects followed the dream of Le Corbusier and decided to build houses in the sky. Scant thought was given to fire safety or means of escape.
Once a building has been designed with these flaws it is difficult to upgrade and put things right, but not impossible. During its life Grenfell Tower would have been upgraded twice possibly three times, again with the design by my profession. Obviously we didn't learn.
Something was seriously wrong with the design and fitout of that tower. We (architects) are taught to design problems out, fire safety being paramount. Alternative escape routes are designed and primary routes protected with sprinkler systems and fitted with Class 0 Spread of Flame or flame retardant finishes. The relatively short time that building took to become a complete fire ball can only imply that none of those protections were in place, or if they were then poor maintenance or cost cutting or omission minimised their effect.
I just look at the images and scream "this should not happen". There is a professional code. There are building control inspectors. There are fire brigade inspections. There are numerous other safety organisations who are involved in the safety of tall rise buildings. There is a duty of care for God's sake. But still 12 dead and rising. 70-odd injured and hundreds homeless.
I hope the ensuing investigation unearths the criminal activity that caused this to happen, because yes they are criminals. Someone cut corners while others pay with their lives - all to make more profit.
And I somehow feel personally responsible.

Not your fault blue architect, you obviously know your stuff & know all the proper H&S protocols & checks. I think talking to a mate who is ex maintenance that corners have most definitely been cut in this case, i'd imagine it'll come out in the enquiries to come & hopefully tighten up the checks & make buildings safer.
Its a terrible preventable tragedy, RIP to all those who have lost their lives & thoughts are with their families.

pompeygunner wrote:Not your fault blue architect, you obviously know your stuff & know all the proper H&S protocols & checks. I think talking to a mate who is ex maintenance that corners have most definitely been cut in this case, i'd imagine it'll come out in the enquiries to come & hopefully tighten up the checks & make buildings safer.
Its a terrible preventable tragedy, RIP to all those who have lost their lives & thoughts are with their families.

Seconded . BA please try not to,let this get to you , sounds easy I know .

Any thoughts about what the expert said on the BBC about the exterior of the cladding having to be fire resistant , but not the interior ?

As the other guys have said BA....you shouldn't feel that you, or indeed your profession have responsibility for this tragedy.

There are a multitude of statutory bodies who's responsibility it is to check these towers....during construction, during routine maintenance, at insurance renewal etc etc. Clearly something has gone terribly wrong but we won't know what / who / how until the outcome of the full investigation by the H&S Executive has been published.....which will be many months yet.

Meanwhile, all we can do is support those effected....residents, fire crew, and others.

What a ***** few weeks....first Manchester, then London Bridge, now this.

Number 1 Jasper wrote: Any thoughts about what the expert said on the BBC about the exterior of the cladding having to be fire resistant , but not the interior ?

Firstly, thank you for your kind words.

I am no expert but my opinion is that the buildings rain screen erected during the last re-fit is the culprit.
A rain screen sits off the main structure by as much as 200mm and acts as an independent weatherproofing. I believe the cladding has to have a degree of fire retardant but not be fully fire resistant (with the degree of retardant unfortunately not set in stone). Behind the screen can be packed additional thermal insulation, many of which have a good level of fire resistance eg Rockwool but others which are cheaper and thinner not so. Effectively you are increasing the size of the building and economies can be made by using 150mm supporting rails rather than 175mm rails, so often the thinner insulation is used - it is there for thermal reasons not fire.
Because the outer wall of the building has been moved out the existing windows will not line up with the new cladding so often these are replaced and repositioned to line up, generally with new double glazed units - sometimes in Upvc frames. The gap between the original window and the new being dressed and infilled.
How a fire from inside a flat migrates to the cladding is the first concern. Each flat should be a fire safe box, however over a period of time service holes are cut and generally never effectively resealed with intumescent filler. If this is repeated over all the flats then there is a possible migration path.
Once the fire gets to the back of the cladding then there is an un avoidable cavity where horizontal and vertical cladding rails are fitted to the face of the building to support the rainscreen panels and contain the insulation which too is fixed back to the main structure. Recommendations are that this void (which should be designed to be as minimum as possible) contains cavity barriers at the boundary of each dwelling, so if a fire develops in the cavity it has limited migrational routes
The evidence shows that the fire spread with frightening speed behind the rain screen within this void and acted as a chimney. Whether the cavity fire barriers worked or where even there I don't know, but the intensity of the heat burnt through the aluminium rain screen causing it to turn into liquid fire. With that intensity of radiant heat the fire would have leaped across the barrier in any case but possible kept localised.
Once taken hold in the void any poorly fire insulated service void or duct would have fed the fire directly into the heart of the flat. Each would have mechanical ventilation from the kitchen and bathroom (likely sited towards the centre of the block as window views are precious), these need to be vented to the outside. The potential void around the repositioned windows also would be a weak point.
So, small fire in kitchen, this migrates through service void/poor fire compartmentation to cladding void that acts as a fuel and accelerant and which by its design creates the draw of a chimney spreading the flame around the perimeter of the building. Any other poor compartmentation in this void compromises the other flats and feeds in new fuel.
I think a pyrotechnics designer would find it difficult to design a more effective system of spreading fire across those distances so quickly

My thoughts go to those effected. RIP the 12 known so far and for those yet to be found.

I have a certain amount of experience in this specific area (I have the wonderful qualification of the FDIS Diploma in Fire Doors! Wowsers).

This fire spread throughout the entire building in around 30 minutes, despite the fire service attending within 6 minutes.

You will all be aware that large buildings such as this have doors which are designed to withstand fire for a specified period of time. The doors to the flats will have been rated FD30S, in other words, they should be certified as withstanding the spread of fire and smoke for a minimum period of 30 minutes. The doors in the circulation areas, ie corridors and stairwells, will have been rated FD60S, which would withstand fire and smoke for 60 minutes.

Obviously, my expertise is in doors, but I do know that there must also be fire protection in any holes between floors and structural walls, etc., ie for cables, pipes etc.

Generally, the aim of this is to keep the fire contained within its "compartment" to allow safe escape via other areas/routes.

In the case of Grenfell Tower, the fire action plan specifically stated that residents should "Sit Tight", on the basis that, theoretically, they would be safe for at least 30 minutes, assuming that the fire was right outside their door.

Clearly, the compartmentation precautions have failed catastrophically here. I find it difficult to believe that any architectural practice would fail to specify these precautions correctly. As BA will testify, these things are deeply ingrained in them, both at Architect School and in CPD opportunities.

To my logic, had there been correct fire doors in place, but perhaps without the correct seals, then the spread of fire would have been much slower than the 30 minutes in this instance. For the fire to spread that quickly, it seems to me that it had an unimpeded course through the building.

It's been hot during the last few days, and it may be that residents had wedged the circulation doors open, to enable a breeze to blow through to keep them cool. However, I would be surprised if sufficient of them were wedged open enough to allow the fire to spread that quickly.

The alternative scenario is that someone, somewhere, has tried to cut corners, maybe non-certificated doors were used in the recent refurbishment. Perhaps there were no seals around the doors at all. Perhaps there was no fire protection seals between floors on the ducts for the electric cables and gas pipes. Maybe it was a combination of those things.

Perhaps it was the architect after all, who failed to specify all these things.

Whichever is the case, someone, somewhere, is having some sleepless nights. They could easily be facing a custodial sentence.

blue architect wrote:

Number 1 Jasper wrote: Any thoughts about what the expert said on the BBC about the exterior of the cladding having to be fire resistant , but not the interior ?

Firstly, thank you for your kind words.

I am no expert but my opinion is that the buildings rain screen erected during the last re-fit is the culprit.
A rain screen sits off the main structure by as much as 200mm and acts as an independent weatherproofing. I believe the cladding has to have a degree of fire retardant but not be fully fire resistant (with the degree of retardant unfortunately not set in stone). Behind the screen can be packed additional thermal insulation, many of which have a good level of fire resistance eg Rockwool but others which are cheaper and thinner not so. Effectively you are increasing the size of the building and economies can be made by using 150mm supporting rails rather than 175mm rails, so often the thinner insulation is used - it is there for thermal reasons not fire.
Because the outer wall of the building has been moved out the existing windows will not line up with the new cladding so often these are replaced and repositioned to line up, generally with new double glazed units - sometimes in Upvc frames. The gap between the original window and the new being dressed and infilled.
How a fire from inside a flat migrates to the cladding is the first concern. Each flat should be a fire safe box, however over a period of time service holes are cut and generally never effectively resealed with intumescent filler. If this is repeated over all the flats then there is a possible migration path.
Once the fire gets to the back of the cladding then there is an un avoidable cavity where horizontal and vertical cladding rails are fitted to the face of the building to support the rainscreen panels and contain the insulation which too is fixed back to the main structure. Recommendations are that this void (which should be designed to be as minimum as possible) contains cavity barriers at the boundary of each dwelling, so if a fire develops in the cavity it has limited migrational routes
The evidence shows that the fire spread with frightening speed behind the rain screen within this void and acted as a chimney. Whether the cavity fire barriers worked or where even there I don't know, but the intensity of the heat burnt through the aluminium rain screen causing it to turn into liquid fire. With that intensity of radiant heat the fire would have leaped across the barrier in any case but possible kept localised.
Once taken hold in the void any poorly fire insulated service void or duct would have fed the fire directly into the heart of the flat. Each would have mechanical ventilation from the kitchen and bathroom (likely sited towards the centre of the block as window views are precious), these need to be vented to the outside. The potential void around the repositioned windows also would be a weak point.
So, small fire in kitchen, this migrates through service void/poor fire compartmentation to cladding void that acts as a fuel and accelerant and which by its design creates the draw of a chimney spreading the flame around the perimeter of the building. Any other poor compartmentation in this void compromises the other flats and feeds in new fuel.
I think a pyrotechnics designer would find it difficult to design a more effective system of spreading fire across those distances so quickly

My thoughts go to those effected. RIP the 12 known so far and for those yet to be found.

Thank you for the info .

Take Care