Quantity of Cement, Sand & Water required for Plastering

Quantity of Cement, Sand & Water required for Plastering:-

Plastering refers to protecting a wall or ceiling by laying a plaster (Cement plaster). Plastering is done to remove surface imperfections caused by brickwork and to keep the surface smooth for painting.

There are many different types of plastering materials out of them, cement plaster is extensively used. Some other types of plastering materials include lime plaster, clay plaster, etc.

How to select the right plastering material for your house?

In any type of plastering two major factors are considered they are Surface Protection and the cost of material. If the quality of plastering is increased and taken higher, then the cost is affected. If price is considered and Quality of plaster are taken lesser importance then the surface protection is compromised.

  1. Plastering material should be cheap and economical.
  2. It should be durable enough to sustain any climatic changes in the entire life span of structure.
  3. Plastering material should have excellent workability which can be applied during any weather conditions.

Let us calculate the quantity raw materials (Cement, Sand & water) required for cement plaster. Though the same process is applicable for any other types of plastering materials.

Calculating the quantities of Cement & Sand required for plastering:

General points to be remembered in Plastering work calculation

  • The ratios mentioned in plastering are volumetric ratios of Cement & Sand (Ex. Cement:Sand = 1:5, 1 part of cement and 5 parts of sand in a mortar).
  • The overall thickness of plastering should be minimum 20mm including two coats.
  • Cement has a dry density volume of 1440Kg/m3
  • Each bag of cement weighs = 50 Kgs or 110 lbs
  • The Volume of each cement bag = 50Kgs/1440 = 0.0348 m3.
  • The dry density of sand = 1600Kgs/m3
  • The plastering is done in two layers (two coats): The first coat of plastering is laid with the thickness of minimum 12mm (usually ranges between 12-15mm) and this coat is called as a Rough coat or Primary coat.
  • The second coat should be laid with the thickness of 8mm and this is called as a Finish coat or Secondary coat of plastering.

Total Plastering = First coat + Second Coat

Different ratios of Cement mortar used for plastering are tabulated below:

Mix RatioAreas of usage
1:6 & 1:5This ratio is usually used for Internal plastering of bricks
1:4Used for Ceiling and external walls
1:3As its a rich mortar mix and it is used where external walls are prone to severe climatic conditions.
It is also used for repair works.

Steps involved in calculation of plastering quantities:

  1. Find the total area of wall to be plastered in Sqm (m2).
  2. Consider the ratio and thickness of plastering
  3. Calculate the Total Volume of Plastering
  4. Find out the Volume of Cement and Sand individually for both the coats
  5. Calculate the total volume of cement & Sand required for plastering

Now coming to the calculation part,

We are considering the below values for calculation purpose:

  1. Wall width and height is 10m and 10m.
  2. Ratio of First coat of plastering (Cement:Sand = 1:5) with the thickness of 12mm.
  3. the ratio of secondary coat of plastering (Cement:Sand = 1:3) with the thickness of 8mm.

Step 1: Calculate the Area of Plastering

Area = width x height = 10 x 10 = 100m2

Step 2: Find the Volume of Plastering 

Volume of First Coat = Area of Plastering x Thickness of Plastering

= 100m2 x 12mm (Convert mm to m)

= 100×0.012 = 1.2m3

Hence, Volume of First Coat of Plastering = 1.2m3

The volume of Second Coat = Area of Plastering x Thickness of Plastering

= 100m2 x 8mm (Convert mm to m)

= 100×0.008 = 0.8m3

Therefore Volume of  Second coat of plastering = 0.8m3

Step 3: Finding the individual quantities of Cement and Sand.

First coat ratio = 1:5 (1 part of Cement and 5 parts of Sand)

Total parts = 1+5 = 6

Quantity of Cement required for First coat =

(Total Volume of first coat plastering  x No. of Parts of cement) ÷ Total Parts

= 1.2 x 1/6  = 0.2m3

Quantity of Sand required for First coat =

(Total Volume of first coat plastering x No. of parts of sand) ÷ Total Parts

= 0.8 x 5/ 6 = 1.0m3

Similarly for Second coat,

Second coat ratio = 1:3 (1 part of cement and 3 parts of sand)

Total parts = 1+3 =4

Quantity of Cement required for Second coat

= (Total Volume of second coat plastering  x No. of Parts of cement) ÷ Total Parts

= 0.8 x 1/4 = 0.2m3

Quantity of Sand required for Second coat

= (Total Volume of second coat plastering x No. of parts of sand)÷ Total Parts

= 0.8 x 3/4 = 0.6m3

 

 

Step 4: Finding the quantity of water required for plastering:

Amount of water to be added in mix depends upon the moisture content present in cement, sand & atmosphere.

Quantity of water = 20% of total dry material (Cement+Sand)
= 20% of (574+2560) = 0.2 x 3134 = 627 litres.

 

Final Result:

As mentioned above volume of 1 bag of cement (50kgs) = 0.0348m3
For 0.4m3 = 0.4 x 50 / 0.0348 = 574Kgs = 11.4bags

Similarly,  for Sand 1m3 = 1600Kgs.
1.6 m3 = 1.6 x 1600 = 2560Kgs = 2.5tonnes

Quantity of Water required = 627litres. 

How many bags of cement are required for 1 square meter of plastering?

If the above mentioned  values are considered for this then (Rough estimate)

From above, 100m2= 574 Kgs of cement
1m2 = 574/100 = 5.7Kgs

Summary:

Quantity of Cement, Sand & Water required for Plastering. For 100m2 of Wall, if first & second coat of cement mortar ratio 1:5 & 1:3 laid then

The Quantity of cement required = 574Kgs
Calculated Quantity of Sand (Fine aggregate) required = 2560Kgs
Quantity of Water required = 627 litres.

Online Plastering Calculator:

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Quantity of Cement, Sand, Aggregate and water required for different grades of concrete

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