Heathrow and Gatwick airports have confirmed they’ve found the sort of porous concrete that has forced schools to close buildings and move students into temporary accommodation.

Heathrow found RAAC in Terminal 3 last year, but says it has carried out some work while it works out a permanent solution.

“Industry has been aware and acting on the remedial steps that should be taken in buildings that contain this material,” it said in a statement to the FT.

“Passenger and colleague safety will always be our first priority. We will continue to update stakeholders across the sector as our plans for permanent solutions progress.”

Gatwick has also detected RAAC, which has an expected lifespan of only 30 years, after which it is liable to crumble. It was widely used in public buildings from the 1950s to the 1990s.

Gatwick said: “We have a register of locations containing RAAC on the airport campus, which are closely monitored through a regular comprehensive structural inspection regime.”

It said a recent inspection, in June this year, ‘did not present any concerns’.

Gatwick said it will continue to monitor the material on a regular basis.

Checks are also being carried out at Manchester Airport, according to the FT.