Large Panel Systems
What Is Wrong With Large Panel System Tower Blocks?
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 below.
BBC Victoria Derbyshire 20th August 2018 with Frances Clarke of Tower Blocks UK
Large Panel Systems feature on BBC Newsnight 15th June 2018
Broadwater Farm Estate, Haringey. Residents campaign video, as they are decanted from their Large Panel blocks
Ronan Point: ‘Grenfell Tower also had construction defects’
By Rhiannon Long,
Published in the Newham Recorder 18 May 2018
By Dr Ali Abbas, senior lecturer in structural engineering at the University of East London.
Dr Ali Abbas is a senior lecturer and expert in structural engineering at the University of East London. He explains the structural defects behind Ronan Point, and gives his view on why, 50 years on, the lessons learned are more important than ever.
Politicians and developers are under immense pressure to deliver affordable housing to address enduring shortages in London. However, this must be funded properly, as the use of cheap construction materials and techniques can end up costing lives.
Ronan Point was a tragedy resulting in deaths and injuries. It was also an eye opener for the construction industry and building regulators. It served as a stark warning for the dangers of design and construction methods which do not adequately safeguard against progressive collapse, which is like a domino effect.
The fall of one tile starts a chain of events leading to the collapse of all tiles, one by one. The iconic photograph of the doomed tower eerily resembles collapsing dominos.The floors (i.e. the domino tiles) in Ronan Point were supported by ready-made walls taking the weight. A gas explosion on the eighteenth floor caused the wall to blow out, meaning the four floors above were left unsupported, leading to them crashing down on the floors below.
There were also construction defects in the joints between ready-made walls and floors. These joints can be particularly challenging in ready-made building components, which are usually used to speed up construction and drive down costs.
The tragedy has led to changes in building regulations to ensure structural robustness requirements, achieved by tying the building together with steel cables, which safeguard against disproportionate collapse.
They also effectively ensure a building’s ability to withstand accidental events like fire and explosions without being disproportionately damaged.The Ronan Point tragedy increased awareness of the importance of adequate design to sustain horizontal pressure on structures, such as a gas explosion or other natural causes such as strong winds.
Recently, another tragedy struck at Grenfell Tower, west London. Construction defects on the façade and gaps led to the fire spreading. As with Ronan Point, cheap and poorly constructed materials were the main cause of tragedy and death. Engineers, regulators and engineering students continue to learn from failure and must keep looking at ways to prevent them happening.
How Was This Allowed To Happen?
The article below from Private Eye 1968, gives a glimpse into the what was going on behind the scenes in Government and industry, following the Ronan Point collapse
Further reading on Large Panel systems
2002 BRE Report: Non-Traditional Housing in the UK
Also visit our Archive page for historical LPS material
2012 Handbook for the Structural Assessment of Large Panel Systems (LPS) Dwelling Blocks for Accidental Loading
1986 BRE Information Paper: Weatherproof Joints in Large Panel Systems.
1986 BRE Report: Overcladding External Walls of Large Panel System Dwellings
1962 Government report which began the launch of industrialised building and LPS.