Gypsum board ceiling, need to use long self-tapping nail?
According to the thickness of gypsum board and several layers of gypsum board to determine.
Monolithic gypsum board (9.5mm or 12mm) with 25mm anti-rust self-tapping screws can be; double gypsum board with 35mm anti-rust self-tapping screws can; other circumstances according to the scene to set.