2017821 calculation of cement, sand quantity for plastering how much cement, sand and water is required for 12mm thick plastering plastering is done on the . 2017615 we will calculate cement and sand for 100 m 2 plastering area in 1:6 ratio and thickness of 12 mm. 100 m 2 x 0.012m 1.2 m 3. (this is wet volume of cement.