Last Friday (3rd July) saw the worst High Rise Fire in London in living memory with 6 people losing their lives in a 1960s tower block.  

I have many years experience of surveying 1960s and 70s tower blocks, and from the limited details so far released, the building looks typical of its age. The design of these towers would probably have been based on British Standard CP3: Chapter IV (1962) and a single staircase would have been permitted.

Each flat should have been designed with internal fire doors, the main corridor would have been provided with cross corridor fire doors, and the staircase itself would be enclosed by fire doors, giving up to 4 door protection between a flat and the staircase.

The building would not have been fitted with a fire alarm, but each individual flat is likely to have had battery operated alarms as part of a local fire brigade initiative.

There has already been a lot of criticism that the single means of escape staircase would not have been wide enough for the occupants of 92 flats to all use. In fact this is true, as the strategy for flats would not expect the whole building to evacuate. Each individual flat should have been constructed a fire tight cell, such that fire should not spread from floor to floor, or flat to flat. Fire Brigade records of most fires in block of flats show that the approach is justified, and it is rare for the fire to spread beyond the flat of origin.

So what went wrong in this case?

From the pictures that we have seen http://bit.ly/1aE5od it appears that the fire started on the 9th floor and spread both up and down the building, which is highly unusual.

There is some sign that burning embers may have fallen down from the fire floor and been blown back into the open windows of flats below. The London Constructional Bylaws of the 1960's would normally have required the floor and an up-stand section of the wall to be constructed of non-combustible material, to prevent fire spread from floor to floor. The flats would frequently be designed with balconies, that project out, giving additional protection against such spread, and often forming an alternate route of escape from one flat to another.

Again the pictures do not show projecting balconies to all floors, nor can we see the non-combustible up-stand section, and this leads me to wonder if the flats were refurbished or extended to the edge of the balcony with non-fire-resisting wall and window panels and the fire-protection effectively removed?

Another problem seems to have been smoke logging of the escape corridors, and according to early eye witness reports, this caused people to stay within the building. Depending on the materials involved, the amount of smoke generated by a fire can be considerable, and the mechanism for dealing with it is vital to prevent the escape route becoming untenable. If for example the entrance door of a flat was damaged or had been replaced with a non fire door, or maybe had the closer removed it would fail to restrain the smoke within the flat, and allow it to spread to the corridor.

A common approach to overcome this risk is to ensure the introduction of a large quantity of fresh air to clear the smoke and make the escape route reasonably safe. However, the issue of whether smoke control or smoke ventilation should be used in such buildings has long been an area of dispute in fire circles.

The design of flats often incorporates permanent or automatically opening ventilation at the two ends of the corridor to produce a through draught, but the principle has some practical objections and weaknesses. For example it is not possible to ensure the amount of air will be enough to clear the smoke, since the horizontal movement of air within a building will depend upon the direction and speed of the wind at the time of the fire.

In the Camberwell case it appears that there are windows at the ends of the corridors, which once may have been permanent openings. There is no indication that the windows opened automatically once the fire started, and again it raises the question of whether or not the block had been refurbished and the correct windows replaced by non-compliant ones.

Whilst it will be some time before the results of an investigation are made available, I would be asking the question - was the building refurbished and did the Building Inspector sign the alterations off?

It may also be relevant to note that the building is in the London Borough of Southwark which has been plagued with problems in its building control department. In 2004 Southwark Planning and Building Control was the subject of an Auditors report which indicated 'serious deficiencies in the processes' and brought to light allegations of wrongdoing and corruption among council officials, that resulted in the suspension of its head of Building Control.

My heartfelt sympathies go out to those who lost a loved one or were otherwise affected by this tradegy. Whatever the cause and the repercussions to come, it is important that we learn from this awful fire and I would urge landlords of similar properties to carry out urgent inspections of fire safety measures, to avoid a repeat.