The Chronicle has conducted an experiment to see how easily cladding removed from three Chester tower blocks went up in flames when introduced to a heat source.
Sanctuary Housing took the decision to take down cladding from the ground floors of Rowlands Heights, Thackeray Towers and Haygarth Heights in Newtown after tests ‘raised some questions about its suitability’.
The Chronicle took discarded samples from a skip then held the pieces of insulation over a blue flame from a camping stove.
This very unscientific test appeared to show the pink foam material was highly combustible once the fire took hold, giving off thick, black, acrid smoke. A sample of polystyrene melted but did not catch light.
It should be pointed out that when in situ the insulating material was encapsulated by a fire resistant brick facade and considered 'low risk', according to Sanctuary.
Sanctuary decided to remove the cladding after test holes were drilled at all nine of its Chester's high rise blocks in the wake of the Grenfell tragedy which has claimed at least 80 lives so far. The exercise was carried out by Cheshire West and Chester Council ’s building control surveyors in conjunction with Sanctuary’s development team.
A spokesperson for the housing association said: “The purpose of the inspections was to confirm that the cladding system and the external insulation used in the construction was non-combustible and therefore safe.”
It continued: “A series of trial holes in the exterior of the building revealed that, although in the majority of the towers tested the cladding was considered safe and compliant, a different insulated cladding system had been used at ground floor level behind the brick façade of Rowlands Heights, Thackeray Towers and Haygarth Heights.
“The technical specification for this different system of cladding insulation raised some questions about its suitability. However, the insulation was completely encapsulated within fire resistant materials and was separated from the rest of the building by the provision of a physical fire proof barrier positioned directly above it.
“In the light of the Grenfell tragedy, with the council we jointly sought advice from Local Authority Building Control (LABC), which is a national body. This advice has been carefully considered and, with the residents’ safety paramount, a decision was taken that the insulation product would be removed immediately and replaced with the same fire resistant insulation used in the upper storeys.”
In addition, Sanctuary has fitted sprinklers in Rowlands Heights and plans are underway to roll out sprinklers to its remaining high rise blocks in Chester and beyond.
Three council-owned blocks in Ellesmere Port do not incorporate cladding and are fitted with sprinklers unless tenants declined – but they will again be approached with the offer to have sprinklers installed.