Understanding Nominal and Standard Bricks in Brick Work Calculation
In the world of construction, one of the most fundamental calculations is the brick work calculation. This calculation ensures that the right amount of materials is available for the construction project while keeping costs in check. A key element in brick work calculation is distinguishing between nominal bricks and standard bricks. Understanding the difference between these two types of bricks is crucial because their dimensions either include or exclude mortar thickness, which significantly impacts the brick work calculation.
1. Nominal Bricks (with Mortar)
Nominal bricks are measured, including the thickness of the mortar layer. In brick work calculation, this inclusion is important because it affects the overall volume occupied by each brick in the structure. This is a common approach in masonry work where the mortar thickness is part of the overall measurement.
- Dimensions (including mortar):
- Length = 200 mm (0.2 m)
- Width = 100 mm (0.1 m)
- Height = 100 mm (0.1 m)
- Volume of a nominal brick in brick work calculation:
Volume = Length × Width × Height
Volume = 0.2 m × 0.1 m × 0.1 m = 0.002 m³ per brick.
The volume of each brick, including the mortar joint, is used to calculate how many bricks are needed per cubic meter of brickwork.
2. Standard Bricks (without Mortar)
In contrast, standard bricks are measured without the mortar thickness. This means that the mortar volume needs to be accounted for separately when doing the brick work calculation. The exclusion of mortar makes standard bricks smaller in size, and the final brick work calculation should adjust for the space that mortar will fill between the bricks.
- Dimensions (excluding mortar):
- Length = 190 mm (0.19 m)
- Width = 90 mm (0.09 m)
- Height = 90 mm (0.09 m)
- Volume of a standard brick in brick work calculation:
Volume = Length × Width × Height
Volume = 0.19 m × 0.09 m × 0.09 m = 0.001539 m³ per brick.
3. Brick Work Calculation for 1 m³ of Brick Work
The purpose of brick work calculation is to determine how many bricks are required to fill a cubic meter of space. Different brick types require different calculations based on whether the mortar is included or not.
1. For Nominal Bricks (including mortar)
When using nominal bricks, the mortar volume is already factored into the dimensions of the brick. This eliminates the need to adjust the calculation for mortar volume, making the process simpler.
- Step 1: Calculate the number of bricks per cubic meter in brick work calculation:
Number of bricks = 1 m³ ÷ Volume of 1 brick
Number of bricks = 1 ÷ 0.002 = 500 bricks (approximately). - Step 2: Add wastage allowance in brick work calculation:
Brick wastage due to breakage or size mismatch is typically 10%. This is an important factor to consider in brick work calculation to ensure that enough bricks are ordered for the project.
Wastage = 500 × 10% = 50 bricks.
Total number of bricks = 500 + 50 = 550 bricks.
Conclusion:
For nominal bricks, approximately 550 bricks per cubic meter are required, including wastage.
2. For Standard Bricks (excluding mortar)
When using standard bricks, the mortar volume is not included in the dimensions of the brick. Since mortar typically occupies about 30% of the total volume in brick masonry, this must be accounted for separately in brick work calculation.
- Step 1: Adjust brick volume for mortar in brick work calculation:
The volume of mortar in 1 m³ = 1 × 30% = 0.3 m³.
The volume of bricks in 1 m³ = 1 × 70% = 0.7 m³. - Step 2: Calculate the number of bricks per cubic meter in brick work calculation:
Number of bricks = Volume of bricks ÷ Volume of 1 standard brick
Number of bricks = 0.7 m³ ÷ 0.001539 m³ = 455.65 bricks (approximately). - Step 3: Add wastage allowance in brick work calculation:
Wastage = 1022 × 10% = 102 bricks.
Total number of bricks = 1022 + 102 = 1124 bricks.
Conclusion:
For standard bricks, approximately 1022 bricks per cubic meter are needed in brick work calculation, including wastage and adjustments for mortar.
4. Key Points to Remember in Brick Work Calculation
The process of brick work calculation can be influenced by a number of factors that can vary depending on the type of construction and regional practices. To ensure that the calculation is as accurate as possible, consider the following key points:
- Mortar Thickness Matters in Brick Work Calculation:
The inclusion or exclusion of mortar thickness can dramatically change the results of a brick work calculation. Nominal bricks already account for the mortar layer, while standard bricks do not, requiring a separate calculation for mortar. - Thumb Rule for Quick Estimation in Brick Work Calculation:
When you need a quick estimate, use the following guidelines:- Nominal bricks: 500–550 bricks/m³
- Standard bricks: 900–1100 bricks/m³
- Material Wastage in Brick Work Calculation:
Wastage is an essential factor in brick work calculation. It’s common to factor in a 5–10% wastage allowance to account for breakage, cutting, or mismatched sizes. This prevents delays in the construction process due to material shortages. - Factors Affecting Brick Count in Brick Work Calculation:
- Mortar joint thickness: Typically 10 mm for standard construction.
- Wall type: Single-layer walls require fewer bricks than double-layer walls.
- Regional practices: Brick sizes and construction techniques can vary by region, which could affect your brick work calculation.
5. Importance of Accurate Brick Work Calculation
Accurate brick work calculation ensures that the construction process is efficient and cost-effective. Here are a few reasons why it’s crucial:
- Optimal Material Usage: Proper calculations prevent the wastage of materials and ensure that the right number of bricks are ordered, preventing over-ordering or under-ordering.
- Reduced Costs: By reducing wastage and ensuring that materials are available as needed, brick work calculation helps lower overall construction costs.
- Efficient Project Planning: Accurate brick work calculation helps in creating realistic timelines and budgets for the project, reducing the risk of delays and cost overruns.
Quality Control in Brick Work Calculation: Always verify the quality and dimensions of the bricks before purchasing. Deviations from standard sizes can impact the accuracy of brick work calculation and the overall quality of the construction.
6. Conclusion
Accurate brick work calculation is essential for effective project management and cost control in construction. By following the steps outlined for both nominal bricks and standard bricks, you can ensure that you order the correct number of bricks for your project while accounting for the appropriate amount of mortar.
For nominal bricks, approximately 550 bricks per cubic meter are required, including wastage. For standard bricks, around 1022 bricks per cubic meter are needed, after adjusting for mortar and wastage.
By applying these principles, you can confidently estimate the number of bricks needed for your construction projects, minimizing waste, reducing costs, and ensuring timely completion. For more advanced brick work calculation, refer to standards such as IS 1077 for bricks and IS 2212 for brick masonry, which provide further guidelines for precise calculations.