The main cinema in Bradford's National Science and Media Museum will remain closed for "at least six months” because of structural safety concerns.
The presence of reinforced aerated autoclaved concrete (RAAC) was discovered in the museum's main auditorium, Pictureville, in September, with a subsequent survey leading to its closure the following month.
RAAC was used extensively in the construction of public buildings between the 1950s and the 1970s. It is described as “much weaker” than traditional concrete by the Standing Committee on Structural Safety, with a lifespan of about 30 years.
A spokesperson for the museum said: "Since 20 October, scoping work on remedial options has been ongoing, and both remedial and permanent fixes are being investigated.
"[We are] working with partners to explore off-site programming options".
The museum has two further cinemas, both already closed for refurbishment, financed by a National Lottery grant.