More than 100 schools in England have been told to fully or partially close because they are fitted with a concrete that could suddenly collapse.

Reinforced autoclaved aerated concrete (Raac) is a lightweight building material used from the 1950s up to the mid-1990s, but is now assessed to be at risk of collapse.

On Thursday, the Department for Education said it had contacted 104 more schools after 52 of the 156 educational settings containing the concrete took protective steps so far this year.

The Government has not yet published a list of the schools that are affected.

Though not confirmed, it is estimated that some 24 schools in England have been told to close entirely because of the presence of Raac, the PA news agency understands.

Here, PA lists some of the schools affected.

– Clacton County High School, Essex

In a letter to parents on Friday, executive headteacher Neil Gallagher confirmed his is one of the schools affected by Raac.

On Monday, the school will be closed for all students. It will only be open for Year 7 pupils on Tuesday, with all other children having online lessons. From Wednesday to Friday, the school will be open for Year 7 and Year 11 only, with other cohorts learning online.

– Hadleigh High School, Suffolk

In a letter to parents on Friday, Penrose Learning Trust chief executive Sarah Skinner and Hadleigh High School headteacher Nicola Shingleton confirmed the Ipswich school was affected and “will need to consider delaying reopening or partial closure until the issue has been resolved”.

“We were only made aware of the requirement to close areas where Raac is present at 3pm yesterday and as such are in the process of emergency planning,” they added.

“We will update you either later today or Monday as to whether we need to delay reopening and/or move to partial opening.”

Ms Skinner told BBC News on Saturday: “In one school I have 10 rooms and a staff room that I can’t use.

“My second school, 16 rooms, the gymnasium and some toilets (out of use), and in my third school 12 rooms (shut). So you can see it’s quite considerable.”

– Kingsdown School in Southend, Essex

Louise Robinson, headteacher of Kingsdown School, called parents of students, who are aged between three and 14, on Thursday to tell them the news that the school will be closed next week due to the aerated concrete.

– East Tilbury Primary School, Thurrock, Essex

Some parts of the school will be closed, with Year 1 pupils moved to share a block with Reception and Year 2 pupils relocated to the sports hall.

– Buckhurst Hill Community Primary School, Essex

The school is closed until September 11 while alternative teaching arrangements are organised.

– Thameside Primary school, Essex

Expects its reopening to students to be delayed until September 11. Parts of the school have been closed, with a significant number of teaching spaces impacted.

– East Bergholt High School, Colchester, Essex

The school is deciding whether to delay reopening or partially close.

– Thurstable school and sixth form, Essex

No students in school on Wednesday, with online learning from home in place. Year 7 is expected to be in school on Thursday, with Year 7, 11, 12 and 13 on-site on Friday, with remote learning for other years.

– The Billericay School, Essex

A number of classrooms will be unavailable while remedial works take place, temporarily reducing the school’s on-site teaching capacity, it has said.

– The Appleton School, Essex

The BBC has reported that the school’s Tower, North and South blocks are being vacated, while Years 8, 9 and 10 are set for online learning from home from Wednesday to Friday.

– Woodville Primary School, Chelmsford, Essex

The school is closed until September 11, the BBC has reported.

– Farlingaye High School, Woodbridge, Suffolk

Some classrooms are set to be out of action and it might need to delay reopening.

– Claydon High School, Suffolk

The school in Ipswich is considering delaying reopening or partial closure until the on-site Raac issue has been resolved.

– Mayflower Primary School, Leicester

Mayflower Primary School is one of three schools in Leicester that have been told they have buildings affected by Raac that need to be taken out of use, Leicester City Council has said.

The school found out it was impacted before the summer holidays, the council said.

– Parks Primary School, Leicester

A “large proportion” of Parks Primary School in Leicester was forced to close in June after a survey revealed Raac was used in its construction.

Headteacher Caroline Evans told Channel 4 News: “In June, we were told we had Raac across the whole of our school and it was in a critical condition, which meant that we had to close a large proportion of our school, leaving only open the reception class and two Year 1 classes and two Year 2 classes.”

Ms Evans was photographed with other staff members in a temporary staff room erected in a school corridor on Friday.

– Willowbrook Mead Primary Academy, Leicester

Another affected school, the Willowbrook Mead Primary Academy on the outskirts of Leicester, has said it will be closed on Monday September 4.

– Aston Manor Academy, Birmingham

The academy has announced a delayed start to the academic year, with students now not expected on the school site until at least September 11.

– Aylesford School, Warwick

The primary school is not affected but a significant area of the rest of the school will be closed while works continue. Only Year 7s will be taught onsite on Monday, with Year 12s returning from Wednesday.

– Wood Green Academy, Wednesbury, West Midlands

Some classrooms will be closed until October.

– St Bede’s Catholic School and Byron Sixth Form College, Peterlee, County Durham

On Friday, the school’s headteacher Frances Cessford wrote to parents to confirm that a “DfE-commissioned survey recently identified that Raac panels were used in the construction” of parts of the school.

She added: “We will therefore be taking part of the school building out of use while we put safety measures in place.

“We are currently working to finalise alternative arrangements and are looking to make provision for all pupils.”

– St James Catholic Primary School, Hebburn, South Tyneside

On Saturday, headteacher Francesca Heslop told parents “the school building is out of use while we put safety measures in place” and that it would “unfortunately” also need to be closed on Tuesday.

– St Teresa’s Catholic Primary School and Carmel College, Darlington

On Friday, Darlington Borough Council said St Teresa’s Catholic Primary School and Carmel College, both members of the Bishop Hogarth Catholic Education Trust, also faced some disruption.

It said St Teresa’s has contacted parents to advise that the Trust has taken the decision to close the primary school for the safety of the children, initially until Monday September 11.

Carmel College has also told parents that the kitchen and library at the college will be temporarily vacated until further investigations have taken place, the council added.

It added: “The college will remain open but there will be some disruption to classrooms and only a limited break and lunch menu. Pupils from Year 7-11 are also asked to take a packed lunch for the first week.”

– Abbey Lane Primary School, Sheffield

Work started in July to replace a roof over the school kitchen after it was identified as containing Raac, Labour MP for Sheffield Heeley Louise Haigh said.

The school is due to reopen on Tuesday and a temporary kitchen has been installed.

– Cleeve Park School, Sidcup

The BBC has reported that four classrooms, some admin offices and the gym will be closed.

– Cockermouth School, Cumbria

Will open on Tuesday instead of Monday after Raac concrete was found in four corridors, the library and the sports hall.

– Donnington Wood Infants School, Telford, Shropshire

Telford and Wrekin Council has said additional safety measures, including extra temporary ceilings, have been installed at the school after Raac was found. It is set to remain open.

– Eldwick Primary School, Bingley, West Yorkshire

Bradford Council has said that access to areas of the school where Raac is present is prohibited.

– St Thomas More Catholic Comprehensive, Eltham, London

Set to open as planned from Tuesday but the hall, gym, canteen, drama studio and boys’ and girls’ toilets are affected by Raac.

The school plans to open mobile toilet blocks and is hiring a marquee as a space for the students to eat and prepare food.

Other affected schools include Cranbourne College in Basingstoke; Crossflatts Primary School in Bingley, near Bradford; Scalby School in Scarborough; St Leonard’s Catholic School in Durham; Winter Gardens Academy in Essex; and Corpus Christi Catholic School in Brixton, London.