Updated February 3rd, 2019
Mortar is a mixture of cement, sand, and water. More specifically it is called cement mortar.
Cement mortar is used in almost all types of masonry work in civil construction. Such as brickwork, plasterwork, tiles work etc.
Although there is dry ready mix mortar available in the market, we often prepare mortar manually in our construction projects.
The main ingredients of mortar are cement and sand.
In a building project, when we want to start any types of masonry work, we need to stack cement and sand in the project.
For stacking cement and sand in the project, we often need to calculate the required quantity of cement and sand for the masonry work. So, let’s see how we can calculate the quantity of cement and sand in the mortar.
How to Calculate The Quantity of Cement And Sand in Mortar
The quantity of sand and cement in mortar can be calculated in two ways. One is by weight and another is by volume.
The easy way to calculate the quantity of cement and sand in mortar is by volume and we often use this method. So, I’ll explain how to calculate cement and sand quantity in the mortar by volume.
First of all, you need to know the required quantity of mortar for your masonry work. Then you need to know the proportion of the cement and sand in the mortar.
Let’s assume out required mortar quantity is 100 cubic feet and the ratio of cement and sand in the mortar is 1:4.
When we say the cement-sand ratio is 1:4, we mean that the mortar contains one part of cement and four parts of sand.
But when we get or buy cement and sand, we get those in dry condition. After adding water in the cement-sand mix, the volume of sand is reduced.
So, when we calculate the quantity of cement and sand in the mortar, we need to consider the reduced volume of the sand.
Considering all these things lets calculate the quantity of cement and sand in the mortar.
Get The Required Quantity of Mortar
Getting the quantity of mortar for plaster work is easy. You just need to get the plastering area and the thickness of plaster. Then multiply the area with thickness. The result is the quantity of mortar for the plasterwork.
Get calculating mortar quantity for masonry wall is a little bit tricky. I’ve talked about this in the post “How to Calculate Materials for Brick Masonry Wall”.
However, for our calculating purpose let’s assume we need 100 cubic feet mortar.
Get The Dry Volume of Mortar
As we get the sand and cement in the dry condition we need to get the mortar quantity in the dry state. But when we calculate mortar for any masonry work, we get the wet quantity of mortar. So, we need to convert the wet quantity into dry quantity.
To get the dry quantity of mortar, we multiply the wet quantity of mortar with 1.27. That means,
The dry quantity of mortar = wet quantity of mortar x 1.27
So, the dry quantity of 100 cubic feet of wet mortar is,
= 100 x 1.27
= 127 cubic feet.
Get The Cement And Sand Quantity in The Mortar
Now it’s time to calculate the quantity of cement and sand in the mortar. For this, we need to know the proportion of cement and sand in the mortar.
Different proportion of cement and sand is used in mortar for different types of masonry work. For our calculating purpose, let’s assume we’ll use 1:4.
That means, we’ll mix one part of cement with four parts of sand to prepare our mortar. The total part of ingredients is,
Calculating The Quantity of Cement
So, the quantity of cement is,
= 127 ÷ 5 × 1
= 25.40 cubic feet
But cement is sold in bags. So, we need to convert the volume of cement into bags. The volume of a 50-kilo bag of cement is 1.25 cubic feet.
So, the bag of cement is,
=25.40 ÷ 1.25
Say, 21 bags.
Calculating The Sand Quantity
The quantity of sand is,
=127 ÷ 5 × 4
=101.60 cubic feet.
Say, 102 cubic feet
Wet mortar volume = 100 Cubic feet
Cement-Sand ratio = 1:4
The Quantity of cement = 21 bags
The quantity of Sand = 102 cubic feet.