MOVABLE CEILING

PURPOSE:To enable the using zone of the facilities of a large space to be enlarged according to various use purposes by permitting a ceiling membrane with enclosed gas lighter than air in specific gravity, to float inside a large frame structure, to be engaged with each other, and by composing a secondary ceiling. CONSTITUTION:In the internal space of an opening or closing type dome roof or the other large frame structure, a plurality of the ceiling membranes 1 of membrane material composed in the shapes of bags which are connected to each other in the plane direction, are formed, and in the ceiling membranes 1, helium gas or the like is enclosed, and buoyancy is imparted. After that, the ceiling membranes 1 are regulated on a required level, and are permitted to float to be engaged with the arbitrary position of ground 4 in the large frame structure. After the application of the membranes 1 is completed, gas in ceiling membrane bodies 5 is removed from and the membranes 1 are received. As a result, the setting work of the ceiling membranes 1 is easily quickened, and the using zone of large space facilities is enlarged, and a secondary ceiling movable according to various use purposes can be easily set.