Before completing the ceiling
During transportation: It should bear the load of their weight.
During the execution of the roof: The dead weight of the roof (weight of blocks, joists and in-situ concrete) along with the weight of people and equipment during concreting must be able to withstand the temporary supports such as piles well. Withstand.
After the full running of the ceiling
After collecting the temporary supports and reaching the resistance of the slab concrete on the joists, the joists will bear the force as a part of the bending of the roof.