Structural flaws in two North London tower blocks should have been caught soon after the Ronan Point disaster in 1968, a leading structural engineer has said.
Two tower blocks on the Broadwater Farm estate in Tottenham could be demolished after structural engineers uncovered serious flaws, meaning the towers could collapse in a gas explosion – as happened at Ronan Point.
The six-storey Tangmere and 18-storey Northolt towers were built in the early 1970s, a few years after the Ronan Point disaster which saw a gas explosion cause a panel to break, causing a progressive collapse on one side.
Now questions are being raised as to why it has taken so long for the faults to be noted.
Concrete Centre head of structural engineering Jenny Burridge said: “I’m suprised they didn’t pick up on the flaws while they were being built.”
She added: ”Our current equivalent of Ronan Point is Grenfell, and you know what’s happening – any cladding going on is currently being looked at.
“I don’t know why it didn’t happen 50 years ago, why they weren’t as worried about that particular thing – making sure that the ties worked – than we are with cladding [after Grenfell].”
A Haringey Council meeting next Tuesday will decide the fate of the two towers, which are likely to be knocked down because the cost of structurally stabilising the buildings is too high.
Structural tests carried out after the Grenfell Tower fire last year uncovered serious structural flaws at 11 of the 12 towers at Broadwater Estate.
Tangmere failed both a 34 kN/m² and a 17 kN/m² structural test, meaning there is a risk of progressive collapse from an explosion caused by piped gas, or a vehicle strike or bottled gas explosion.
As Tangmere has a piped gas supply, residents will be evacuated. Northolt also failed the 17 kN/m² structural test but is not connected to a main gas supply and so residents will not immediately be rehoused.
Although only two towers are being considered for demolition, 11 out of the 12 towers at Broadwater Farm failed the 34 kN/m² test, which is a requirement in the current building regulations.
Like what you’ve read? To receive New Civil Engineer’s daily and weekly newsletters click here.