Many large theatres have been forced to close in recent days after discovering the failing concrete

National Theatre, NT Future, SE1 by Haworth Tompkins

Source: Philip Vile

The National Theatre on London’s South Bank

The National Theatre has appointed engineers to carry out structural surveys of the South Bank venue after discovering reinforced autoclaved aerated concrete in some backstage areas.

Denys Lasdun’s grade II*-listed building was completed in 1976 at a time when the lightweight concrete was used widely across the UK in a range of building types with flat roofs.

The theatre said early investigations suggest the material is safe and does not require immediate remedial works.

It comes after a string of large theatres were closed and forced to cancel performances due to the presence of RAAC, including the grade II-listed St David’s Hall in Cardiff and the Orchard theatre in Dartford.

Other shuttered venues include Carlisle’s Sands Events Centre, Northampton’s Royal & Derngate, the Brunton Theatre in Musselburgh, the Forum Theatre in Stockport and the YMCA theatre in Scarborough.

A spokesperson for the National Theatre said the building is made predominantly from traditional reinforced and post tensioned concrete.

“There are a small number of select backstage areas where RAAC is present,” the theatre said, adding: “Our Structural Engineers are in the process of surveying these areas, initial indications are that they are safe and do not currently require remedial works. 

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“We have always and will continue to take the safety of our staff and audiences very seriously.”

The Ambassadors Theatre Group, which operates 10 venues in the West End and 27 others across the UK, is also “closely monitoring” its sites, according to reports.

Last week the Department for Education told more than 100 schools to close buildings where RAAC has been identified until mitigations, such as structural supports, are in place.

Other government departments are also surveying their estates, including the Ministry of Defence and the Ministry of Justice, which urgently expanded investigations of the court system last month after discovering RAAC in a building completed in the 1990s.

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