How to Calculate the Pointing of Cement and Sand in Masonry Construction

Accurate calculations are essential in any construction project to ensure that the right amount of materials is procured, minimizing waste and staying within project budgets. This guide will walk you through the steps to calculate the quantity of cement and sand needed for a 1MCU (Masonry Construction Unit) built. Additionally, we will explain the concept of pointing in masonry and how to calculate the amount of mortar needed for a 1m2 of brickwork.

Calculating the Quantity of Cement and Sand

To calculate the quantity of cement and sand required for a 1MCU masonry built, follow these steps:

Step 1: Determine the Mix Ratio

The mix ratio is usually specified in the construction plans or can be obtained from the project specifications. For a common mix ratio for masonry mortar, a 1:6 ratio is often used, which means one part of cement is mixed with six parts of sand.

Step 2: Calculate the Total Volume

Measure the total volume of the masonry built in cubic meters. Ensure accurate measurements to avoid errors in the calculation.

Step 3: Calculate the Cement Quantity

To determine the amount of cement needed, multiply the total volume of the masonry built by the proportion of cement in the mix ratio. For example, if the mix ratio is 1:6, the cement quantity would be 1/7 of the total volume. This means if your total volume is 7 cubic meters, you would need 1 cubic meter of cement.

Step 4: Calculate the Sand Quantity

Calculate the sand quantity by multiplying the total volume of the masonry built by the proportion of sand in the mix ratio. For a 1:6 ratio, the sand quantity would be 6/7 of the total volume. Using the same example, if your total volume is 7 cubic meters, you would need 6 cubic meters of sand.

Important Considerations

Remember that these calculations are based on the assumption that the mix ratio and proportions remain constant throughout the entire masonry project. It is essential to double-check the mix ratio and consult the project specifications to ensure accurate calculations. Additionally, take into account any wastage or additional requirements specified by the project.

Understanding Pointing in Masonry

“Pointing” is the process of finishing the mortar joints in masonry to provide a neat and professional appearance. The quantity of mortar required for pointing is specified as the amount needed for square meters of masonry surface, not on the cubic meter of masonry.

Calculation for Mortar Quantity for 1m2 Brickwork

To calculate the quantity of mortar needed for 1m2 of brickwork, follow these steps:

Step 1: Determine the Number of Bricks

There are typically 60 bricks per square meter. Each brick is laid with an approximate 10mm joint, which requires a certain amount of mortar.

Step 2: Calculate the Volume of Mortar

Approximately 0.022 cubic meters of wet sand and cement mix is required to lay the bricks with 10mm joints. This is equivalent to approximately 60kg of mortar.

Step 3: Calculate the Sand and Cement Ratio

Using a 4:1 sand to cement mix, the distribution would be as follows:

45kg of sand (which is 4/5 of 60kg) 15kg of cement (which is 1/5 of 60kg)

By following these steps, you can accurately calculate the amount of cement and sand needed for your masonry project, ensuring efficient use of materials and a professional finish.