ROSS High School’s dining hall is set to be closed until after the October break following the discovery of a potentially dangerous form of concrete.

A letter was sent to parents and carers on Tuesday highlighting that, although Reinforced Autoclaved Aerated Concrete (RAAC) had been found in the secondary school's dining hall, it was safe to use.

Now, a follow up letter has been sent out by Nicola McDowell, East Lothian Council’s head of education.

She said: “Survey work established that RAAC is present in the dining hall at Ross High School.

“As stated in the recent letter, the RAAC which is present at Ross High is being closely monitored to establish whether any work might be required.

“Further assessment work has taken place since my letter of Tuesday.

“While it remains the case that the RAAC is in a better condition than buildings elsewhere, we have been advised that work will be required to improve the bearing of the RAAC panels.

READ MORE: Ross High School dining hall 'safe to use' following RAAC discovery

“This involves the installation of supplemental steel supports where required.

“Although a full report on this is awaited, we believe that it is best to take decisive action and arrange for this to be done as soon as possible.

“Therefore, as a temporary and precautionary measure, the dining hall is being taken out of immediate use and arrangements are being made for work to proceed.

“It is anticipated that this can be completed ahead of school resuming after the October half term break and so our expectation is that the dining hall will then re-open.”

RAAC is a lightweight form of precast concrete and was frequently used in public sector buildings across the country from the mid-1960s to at least the mid-1980s.

READ MORE: Prestonpans: high school partially closed but exams still to go ahead

Already, the material has been identified at the Brunton theatre in Musselburgh and Preston Lodge High School in Prestonpans.

To ensure public safety, much of The Brunton has been closed since March while 23 classrooms have been closed at the Prestonpans secondary school.

Mrs McDowell said “temporary arrangements” would be in place from Monday at the Tranent secondary school, with pupils to be provided with “an adjusted school lunch menu from the social space”.

She said: “Mr Reynolds will be providing further details about this to students on Monday.

“We appreciate this will cause inconvenience but believe that, as this new information has come to light, it is important to take decisive action.

“Everyone’s health and safety is our top priority and I would like to re-assure you that no other area of the building at Ross High is affected and we will provide further updates in relation to the dining hall in due course.”