Long-awaited structural report on Ledbury towers confirms gas explosion would have caused collapse

Owen Sheppard (31 August, 2017) Housing

Report confirmed that tower block walls and ceilings would have collapsed in the event of a gas explosion, since they were built 50 years ago

17832The Ledbury Estate, off Old Kent Road

A structural assessment of the Ledbury Estate towers has confirmed they have been vulnerable to collapse from a gas explosion since they were built, nearly 50 years ago.

A report published today, produced by structural surveyors Arup, has outlined the investigations carried out to date on two of the four fourteen-storey blocks.

It confirms that strengthening works – which should have been given to all UK tower blocks following the Ronan Point tower block collapse of 1968 – never happened at the Ledbury.

It also confirms the Ledbury towers were never fit to carry gas pipes. Southwark Council has also confirmed to the News that since gas supplies were switched off on August 11, their plan is for the blocks to become fully electric and for all gas provision to be permanently removed.

Surveyors inspected the concrete-fitted construction between walls, floors and ceilings in two empty flats (in Skenfrith house and Bromyard house), between July and August.

Suspicions about the structural safety of the blocks were first raised with the council and residents by independent surveyors Arnold Tarling and Tony Bird. And it was later realised that records of the towers’ design – dating back to 1968-70 when the blocks were built by the Greater London Council – had been lost. So there was no record of whether the strengthening works happened.

Outlining their findings, Arup’s report said: “No reinforcement was detected in the internal loadbearing walls or the internal leaf of the external loadbearing walls… As such the walls would fail under a 34kPa and also a 17kPa blast load (blast pressures for piped and bottled gas)…

“The loss of walls would undermine the support to the floor slabs immediately above and investigations of the connection between the floor slabs and wall above show that the connection is incapable of supporting the weight of the floor in tension.”

However the report states that Arup will carry out further tests on many more flats, before it can be determined what should happen next, and whether it would be “feasible” to carry out strengthening works.

A Southwark Council spokeswoman told the News that these further tests could be completed, and a further report produced, by November 20.

Today’s report suggests: “If it is considered feasible to strengthen the building then conceptual structural remedial designs will be produced for high level costing enabling Southwark Council to assess in conjunction with the other works.”

Cllr Stephanie Cryan, deputy council leader and cabinet member for housing

Stephanie Cryan, deputy leader and cabinet member for housing, said: “This report expands on what we already knew and have communicated to residents – that the blocks should not have had a gas heating and hot water system installed in the 1960s without adequate strengthening work.

Of course, as soon as we found this out on August 11, we turned off the gas, so the risk has been removed, and we are continuing our investigations.

“The wider question remains why the blocks may not have been sufficiently strengthened when they were built in the late 1960s before the council took ownership in the 1980s, and whether other blocks elsewhere in the country are affected.

“With that in mind we met with [Department of Communities and Local Government] DCLG this week, and have also now shared the Arup report with them. At a public meeting last week I apologised to our residents for the distress and inconvenience these issues have caused, and the council continues to offer every support we can while we resolve the issues on the Ledbury.”

Images provided by Ledbury Estate residents, who complained that cracks in their walls were a serious fire risk

Arup were first brought into assess the blocks at the end of June, after one resident raised concerns with the London Fire Brigade about cracks in the walls of Lebdury Estate flats. Although it was acknowledged early on that the cracked walls had long undermined the compartmentation fire-safety features of the flats, Arup’s report also reaffirms that the cracks did not pose a structural threat to the buildings.