GYPSUM FALSE CEILING –
The gypsum false ceiling consists of gypsum boards which are fixed over a support system of GI framework. Gypsum, which is hydrated calcium silicate, is available in boards of 9mm, 12.5mm and 15mm thicknesses. The boards are available in sizes of 1200mm x 2400mm.
The different parts of the supporting system are –
· GI suspenders, which are fixed onto the slab above by means of a soffit cleat.
· The suspenders are then fixed onto the Primary channel, which is at 1200mm centre to centre in either direction.
· Below the primary channels are the secondary channels or the ceiling section, which is screwed onto the primary channel. The ceiling sections are spaced at 457mm centre to centre in either direction.
· Perimeter channels are to be fixed onto the walls
· The gypsum boards are screwed onto these ceiling sections with self taping screws.
· The joints of the gypsum boards are finished with a special paper tape over which jointing compound is applied (3 coats of increasing widths of 150mm,300mm and 450mm), to prevent the formation of cracks.
· These joints are finally sanded well and the board is painted over using normal emulsion paint.
India gypsum, Saint Gobain etc.
MOISTURE RESISTANT BOARDS –
Moisture resistant boards or MR boards are available for application in areas where there is possibility of moisture content, as normal gypsum boards will deteriorate.
THINGS TO CONSIDER –
· The edges of the boards are to be treated carefully, especially at the junction of horizontal and vertical boards. Special corner beads are available for such applications, to ensure a good finish.
· The jointing between the boards are to be done as specified, to ensure a smooth finish, and also to avoid formation of cracks.