Caerphilly county borough council say that parts of Cwmcarn High School will be able to be reopened to students from Friday.
In a statement the council said the "newest part of the school is available for use and is separate from the rest of the school buildings."
The school was closed to students on Friday after an investigation found asbestos particles in the air.
– Caerphilly county borough council statement
The council took the difficult decision to close the school in light of the findings of a structural report and we are not prepared to fully re-open the site until further investigations have taken place to determine the extent of the problem and the work needed to address the situation. A range of options are being investigated for the other age groups and further updates will be posted on the council and school websites.