supply of material.- providing & fixing of armstrong soft fibre acoustical suspended ceiling system with optra ( bevelled tegular ) edge tiles with armstrong 15mm exposed grid.the tiles should have humidity resistance ( rh ) of 95%, nrc 0.9 - 1.0, light reflectance =85%, colour white, fire performance uk class 0 / class 1 ( bs 476 pt - 6 &7 ) in module size of 600 x 600 x 20mm , suitable for green building application, with recycled content of 66% gw & 74% rw. the tile shall be laid on armstrong silhouette profile grid system with 15mm white flanges incorporating a 6mm central reveal in white / black colour and with a web height of 38 mm and a load carrying capacity of minimum 15.68 kgs / m2 with a minimum pull out strength of 100 kgs. silhouette, main runners & cross tees to have mitred ends & “birdsmouth” notches to provide mitred cruciform junctions. the t sections have a galvanizing of 90 grams per m2 and need to be installed with suspension system of armstrong make.the tile & grid system used together should carry a 10 year warranty. including t&p scaffolding as per site required for proper completion of work.