How To calculate The Cement, Sand Quantity For Plastering

Mortar ratio = 1:6 where 1 is cement and 6 part is sand.

Plaster thickness = 12 mm = 0.012 m

Cement density = 1440 kg/m3

1 m3 = 35.3147 ft3

Suggested Plaster Thickness

12 mm for internal walls or brick wall plain surface

15 mm for 4” or 9” brick wall rough surface 20 mm for two plaster layers normally utilized for external walls

Mortar Wet volume = 1 x 1 x 0.012 = 0.012 m3

Mortar Dry volume = 0.012 x 1.30 = 0.0156 m3

 Mortar Dry volume (sand + cement) = 30 – 35 % greater than wet volume = wet volume x 1.30

Concrete Dry volume (aggregate + sand + cement) = wet volume x 1.54

As we know that mortar ratio = 1:6, from which 1 + 6 = 7 = sum of ratio

Amount of cement in plaster = 1/7 x 0.0156 x 1440 = 3.21 kg

Also in bags = 3.21/50 = 0.064 bag = approximately 1 bag

Amount of sand in plaster = 6/7 x 0.0156 = 0.0133 m3

Sand quantity in cubic feet = 0.0133 x 35.3147 = 0.47 ft3