Cement Plastering: Calculating Cement and Sand for Plastering and Brickwork

Introduction of Cement Plastering:

Cement plastering is the process in which the cement mortar is applied to the surface of the wall to protect it from the penetration of water and other aggressive environmental conditions.

In this article, we will see how to calculate the amount of cement & sand required for plastering and how to calculate the cement sand quantity for brickwork.

The cement mortar ratio which is generally used for the plastering depends upon the type of plastering work. There are various types of cement mortar ratio are used for different types of cement plaster design.

The plastering ratio which is recommended for the plastering of the plane surface, the rough surface of the brick wall, and the rough surface of the concrete walls and ceilings are 1:6, 1:4 and 1:5, and 1:3 are used respectively.

How Many Cement Bags Per Square Metre for Plastering?

Step 1: Volume of Plaster.

Here we will calculate the cement consumption in plaster for a 1 square metre area.

Let us take the plastering thickness for the surface of the brickwork is 12mm in a ratio 1:6(cement : sand). First upon we have to calculate the volume of the cement mortar which is required for the plastering work of one square metre area.

Volume of Plaster = L x B x t

Here,

L = Length of the plastering surface= 1 m

B=  breadth of the plastering surface= 1 m

t = thickness of the plaster= 12 mm = 0.012 m

Volume of Plaster= 1 x 1 x 0.012

  Wet volume of Plaster = 0.012 m³

Step 2: Dry Volume of Plaster.

Here we have to calculate the dry volume of the plaster in order to find the consumption of the cement for the plaster.

Dry Volume of Plaster = 1.33. x wet volume of the plaster

Dry Volume of Plaster = 1.33 x 0.012

Dry Volume of Plaster = 0.01596 m³

Note: The Dry volume of the plaster is calculated and used in the formula because the quantity of the cement we are calculating is in the dry state.

Step 3: Volume of Cement in M³.

The Cement calculation formula for plastering are as follows.

Volume of Cement = ( Ratio of cement/Sum of the ratio of cement and sand ) x Dry Volume of Plaster

Volume of Cement = (1 / 7) x 0.01596

Volume of Cement = 0.0028 m³

Step 4: Volume of Cement in Bags.

Hence, the number of cement bags calculated are as follows.

Number of Bags = Volume of Cement/Volume of One Bag of Cement

Number of Bags = ( 0.0028/ 0.0347)

Number of Bags = 0.08 bag

We know that,

The volume of one bag of cement is 0.0347 m³

Step 5: Volume of Cement in Kg.

Calculating the cement consumption for the plastering work in kg.

Volume of Cement in Kg. = Density of Cement x Volume of Cement 

Volume of Cement in Kg. = 1440 x 0.0028

Volume of Cement in Kg. = Density of Cement x Volume of Cement 

Volume of Cement in Kg. = 4.032 Kg 

We know that,

1. The density of cement is 1440 kg per m³
2. There are 0.08 cement bag is required for the plastering work of one square metre.

How to Calculate the Cement Sand Quantity for Plastering?

The method of calculating the quantity of cement and sand which is required for the plastering work is as follows.

How to Calculate Plastering Quantity?

First upon calculating the total area where plaster has to be applied. Then calculate the wet volume of that area where plaster is to be applied.

Wet volume of plaster = Area of Plaster x Plastering Thickness

We have to calculate the dry volumes of the plaster. The formula to calculate the Dry volume of the plaster are as follows.

Dry volume of plaster = 1.33 x Wet volume of Plaster

To calculate the quantity of cement.

Cement = (Ratio of Cement Sum of Ratio of Cement and Sand) x Dry Volume of Plaster

Here we will get the quantity of cement in m³ and we can calculate the consumption of cement for plastering work by dividing the total cement quantity by the volume of one cement bag. After that, we have to calculate the quantity of sand required for the plastering work.

Sand quantity = (Ratio of Cement Sum of Ratio of Cement and Sand) X Dry Volume of Plaster

Here we will get the quantity of sand required for the plastering work.

How Much Cement in 1 Cubic Metre Brickwork?

Here we will calculate how much sand and cement for brickwork.

1. The size of the modular brick is 190 x 90 x 90 mm.
2. Mortar Thickness is 10mm.
3. Assume required brickwork volume is 1 cubic metre (m³).

How to Calculate Quantity of Cement Mortar in Brickwork and Plaster?

1. The brickwork consists of bricks and cement mortar.
2. So firstly we have to find the volume of bricks with mortar thickness and the volume of bricks alone.

Volume of Bricks with Mortar.

Size of Brick without mortar = 190 x 90 x 90 mm

Volume of 1 brick with mortar = 200 x 100 x 100 mm

(by taking 10 mm mortar thickness on all sides)

So that the number of bricks required for 1 cubic metre is as follows.

Bricks Qty = Calucrtion Area/ Volume of 1 Brick with Mortar.

Bricks Qty. = 1/0.002

Bricks Qty. = 500 nos

Here,

1. Volume of 1 brick with mortar = 0.2 x 0.1 x 0.1 m
2. Volume of 1 brick with mortar = 0.002 Cu.m. (m³)
3. The Volume of brick with mortar = 0.002 Cu.m. (m³)

There are total 500 number of bricks are required for the construction of the one cubic metre brickwork.

Volume of Bricks Without Mortar.

1. Volume of 1 brick without mortar in mm = 190 x 90 x 90 mm
2. Volume of bricks without mortar in m= 0.19 X 0.09 X0.09.
3. Volume of 1 brick without mortar in cubic metre   =  0.001539 Cu.m. (m³)
4. Volume of 500 bricks without mortar in cubic metre = 500 X 0.001539 Cu.m. (m³)
5. Volume of bricks without mortar for 1 cubic metre= 0.7695 Cu.m. (m³)

How to Calculate Cement Consumption in Brickwork?

After that, we have to calculate the amount of cement mortar required for brickwork

1. Required Amount of Cement Mortar = 1 m³ – Volume of Bricks without Mortar
2. Required Amount of Cement Mortar = 1 – 0.7695
3. Required Amount of Cement mortar  = 0.2305 Cu.m.  (m³) (Wet Condition)

The volume is in a wet state so that we need 0.2305 cement mortar in mixed condition (after adding water). In order to calculate the dry volume, we have to multiply 33 % as bulkage of sand.

1. Dry Volume of a Mortarr = Required Amount of Cement mortar x [(100 + 300) %]
2. Dry Volume of a Mortar = 0.2305 m³ x 1.33
3. Dry Volume of a Mortar = 0.306565 m³

We know the cement mortar ratio for brickwork is 1:6 (where the 1 part is of Cement and the 6 Part Sand).

The sum of this cement sand Ratio is = 1+6 = 7.

1. Required Amount Cement Quantity in Brickwork = Dry Volume of a Mortar x Cement Sand Ratio x Density of Cement 
2. Required Amount Cement Quantity in Brickwork = 0.306565 x 1/7 x 1440 kg
3. Required Amount Cement Quantity in Brickwork = 63 Kg
4. Required Amount Cement Quantity in Brickwork = 63 kg/ 50 kg ( Cement Bag Weight)
5. Required Amount Cement Quantity in Brickwork = 1.26 bags
6. Required Amount of Sand = Dry Volume of a Mortar x Sand Cement Ratio
7. Required Amount of Sand = 0.306565 x 6/7
8. Required Amount of Sand = 0.26277 Cubic metre (m³)

So for the construction of 1 cum of brickwork, we need

1. 500 Numbers of brick.
2. 63 kg of cement.
3. 263 m³ of sand.

Frequently Asked Questions (FAQ) on Cement Plastering

What is cement plastering?

Cement plastering is the process of applying cement mortar to wall surfaces to protect them from water penetration and other environmental conditions.

How do you calculate the amount of cement and sand required for plastering?

To calculate the amount of cement and sand required for plastering, you need to:

1. Determine the plastering area.
2. Calculate the wet volume of plaster using the formula: Volume of Plaster = Length x Breadth x Thickness.
3. Convert the wet volume to dry volume by multiplying by 1.33.
4. Calculate the volume of cement and sand using their respective ratios.

What is the recommended cement mortar ratio for plastering?

The recommended cement mortar ratios for different types of plastering are:

1. Plane surface: 1:6 (cement: sand)
2. Rough surface of brick walls: 1:4
3. Rough surface of concrete walls and ceilings: 1:5 and 1:3

How many cement bags are required per square metre for plastering?

To determine the number of cement bags needed per square metre:

1. Calculate the wet and dry volumes of plaster.
2. Use the formula: Volume of Cement = (Ratio of cement / Sum of the ratio of cement and sand) x Dry Volume of Plaster.
3. Convert the volume of cement to the number of cement bags using the volume of one bag of cement (0.0347 m³).

How do you calculate the quantity of cement and sand for brickwork?

To calculate the quantity of cement and sand for brickwork:

1. Determine the volume of brickwork and the size of the bricks.
2. Calculate the volume of bricks with and without mortar.
3. Calculate the amount of cement mortar required by subtracting the volume of bricks without mortar from the total volume of brickwork.
4. Convert the wet volume of mortar to dry volume by multiplying by 1.33.
5. Use the cement mortar ratio (1:6) to determine the quantities of cement and sand.

What is the size of a standard modular brick?

The size of a standard modular brick is 190 x 90 x 90 mm.

How much cement is required for 1 cubic metre of brickwork?

For 1 cubic metre of brickwork, you need:

1. 500 bricks
2. 63 kg of cement (approximately 1.26 bags)
3. 0.263 m³ of sand

What is the density of cement?

The density of cement is 1440 kg/m³.

How do you convert the volume of cement to kilograms?

To convert the volume of cement to kilograms, use the formula: Volume of Cement in Kg = Density of Cement x Volume of Cement.

Why is the dry volume of plaster greater than the wet volume?

The dry volume of plaster is greater than the wet volume because it accounts for the additional space occupied by air and the bulkage of sand. The dry volume is typically 1.33 times the wet volume.