A boys' school in Highgate has been confirmed as having collapse-risk concrete in one of its blocks.

Islington Council said today (September 12) that it is supporting St Aloysius’ College in Hornsey Lane after the discovery of reinforced autoclaved aerated concrete (Raac).

Raac, lighter and less durable than traditional concrete, was used until the mid-1990s but the Health and Safety Executive said it is now beyond its lifespan and may collapse with little or no notice.

Last week the Department for Education (DfE) published a list of schools with the collapse-prone concrete – but no schools in Islington were identified.

But in a letter to parents on Friday (September 8) the school said that recent testing had identified Raac in “the roof of one of…[its] blocks”.

It added: “Having taken specialist advice, we have relocated classrooms from the top two floors of this block to elsewhere in the building while further testing and remediation works are decided and implemented.”

The school then claimed that despite the presence of the concrete, it was “business as usual”.

Islington Council has said that it is working with the leadership team at St Aloysius' College and the DfE “to ensure remedial work is carried out safely and to give reassurance to parents”.

It added that the school is following all guidance, and there is currently no disruption to teaching.

St Aloysius’ College has been contacted for more information about Raac at its site.

On the topic of Raac, a spokesperson for Islington Council said: “We are taking a proactive approach to ensure safety and currently, across our estate, and the presence of Raac has been confirmed in one school building at St Aloysius' College.

“In schools, expert surveyors continue to check any areas of concern as a precaution, and we are reviewing all the information we hold on our other buildings, including more than 36,000 homes we are responsible for, to identify and prioritise any need for reinspection.”

They added: “This is an evolving situation; we are vigilant to changes in government advice and are working closely with all our partners across the borough to protect the safety of our residents and staff.”

Islington Council also said that there is currently no evidence of Raac in its housing stock, but that it will monitor this closely by undertaking a review of its stock and data.

It added that its external surveyors will look for the presence of Raac in all the properties they survey going forward, and are prioritising inspections of buildings constructed when Raac was in use.