There are two main areas of concern:
The structural design of large panel system blocks is weak, they could collapse in an explosion, high wind or serious fire.
There are frequently gaps between floor and wall panels, these gaps prevent the flats from containing a fire for one hour and lead to the risk of serious fire spread.
The highest risk blocks are those with gas in them.
Why is this an issue now?
Because of the Grenfell fire, tenants, landlords and independent experts have become concerned to ensure that there are no more tower block disasters. The tenants of the Ledbury Estate raised awareness nationally that gas supplies still exist in Large Panel blocks, even though the Government instructed gas to be removed from all blocks that could not withstand an explosion of 5pounds per sq inch(psi). There are blocks with gas in them in a range of London boroughs and in other areas of the UK. Broadwater Farm is the latest estate where this issue has been highlighted.
What is the future for these blocks?
Originally it was expected that these blocks would have a life of 40 years, we are beyond that now. Over the course of their lives various refurbishments have been carried out to improve them and deal with issues such as dampness, condensation, vermin infestations, lack of insulation, high energy costs. In carrying out these works new risks may have been introduced; blocks may be clad in flammable materials, gas heating systems may have been reinstalled, new heating systems and entryphones may have breached the compartmentalisation of the flats. Also, the bowing of the panels is likely to become greater with age.
What should happen?
All large panel system tower blocks should be inspected as a matter of urgency. This needs to be led by experts who are familiar with these structures, it needs to be led by government and the Building Research Establishment. A large panel system block which is going to be demolished should be given to the BRE to inspect as an open site. This will enable structural engineers to ascertain the impact of age on these buildings and the level of risk they now carry. Tenants and tower block landlords will be able to see the findings as the tests will be carried out on an open site and viewed by the media. There is a precedent for this type of inspection, in 1986 Newham Council gave Ronan Point to the BRE to investigate and they discovered that the joints between panels were faulty – packed with newspaper rather than concrete – and could not withstand an explosion, fire or high wind; and in the fire test we saw that a flat could not contain a fire for one hour. The building breached building regulations and it had to be demolished along with 8 other similar blocks.
For tenants views and an explanation of the risk of progressive collapse see this film about Broadwater Farm here.
For a discussion about the scale of the problem see Victoria Live debate here