Are there any specific requirements for the time when the fire sprinklers spray up and down?

Fire sprinklers spray up and down before interior decoration. Content:

Upper spraying: there is no ceiling, and the common parts of slab and beam are exposed, such as underground garage and equipment floor; In the houses put into use, the construction of exposed public parts of ceiling slabs and beams will be suspended in some parts.

Downward spraying: the ceilings of offices, conference halls, lobbies, restaurants and public parts have been completed.

See Code for Design of Automatic Sprinkler System (GB 50084—2005) for the specific requirements of fire sprinkler arrangement.