How to find out the quantity of cement and sand in plastering work

In this construction video tutorial you will learn some useful tips which will help you to calculate the quantity of cement and sand in a plastering work.

The proportion of mortar is taken as 1:6 i.e. one part cement and six part sand.

The density of plaster is taken as 12 mm i.e. 0.012 m

The density of plaster is generally recommended as follow :-

12 mm – Toward plan surface of brick wall or for interior walls.
15 mm – Toward rough surface of 9” or 4” brick wall.
20 mm – Toward two layer of plaster normally applied for exterior walls.
Density of cement = 1440 kg/m³

1 m3 is equivalent to 35.3147 ft³
The density of the wall is 1 m x 1 m and the thickness of plaster is 12 mm.
Volume of mortar will be determined as 1 x 1 x .012 = 0.012 m³ (wet volume)

To covert wet volume to dry volume, the following formula is used :-

0.012 x 1.30 = 0.0156 m³
In dry volume, the mortar is made of cement and sand and it is 30 to 35% more than wet volume

i.e. 1.30 x wet volume
Now, dry volume for concrete is formed with cement, sand and aggregate i.e. 1.54 x wet volume
We already know that dry volume of mortar = 0.0156 m³
Mortar ratio = 1:6 = 1+6 = 7
Density of cement = 1440 kg/m³

The quantity of cement = 1/7 x 0.0156 x 1440 = 3.21 kg
In bags = 3.21/50 = 0.064 bags = 1 bag. (as one cement bag = 50 kg)

The quantity of sand will be determined as follow :-
6/7 x 0.0156 = 0.0133 m³
To covert to cubic feet = 0.0133 x 35.3147 = 0.47 ft³ (as 1 m³ = 35.3147 ft³)

To get online demonstration, watch the following video tutorial.

Video Source TECH@7K