Depth of flat slab: Considering the flat slab as a continuous slab over a span not exceeding 10 m L d = 26 26 L d Depth considering along: Taking effective depth of 25mm Overall depth D = 260 +25 = 285 mm 125 mm (minimum slab thickness as per IS: 456) It is safe to provide depth of 285 mm. g) Estimation of load acting on the slab: Dead load acting on the slab = 0.285 x 25 = 6.25 2 / KN m = 1 d w Floor finishes etc.
load on slab = 1.45 2 / KN m = 2 d w Live load on slab = 7.75 2 / KN m = l w Total dead load = 1 d w + 2 d w =7.7 2 / KN m = d w 10 Longer span Shorter span L =6.6 m , L =5.6 m 1 2 L 6600 d =253.8 mm 26 26 Say 260 mm L =5.6 m , L =6.6 m 1 2 L 5600 d =215.3 mm 26 26 Say 220 mm