How to calculate brick work?

To calculate brickwork accurately, the primary focus is on determining the quantity of bricks needed for your project, alongside essential supplementary materials like mortar and wall ties. This ensures you have enough materials, minimizing waste and additional trips.

How to Calculate Bricks Needed for Brickwork?

Calculating the exact number of bricks required involves measuring the wall area, accounting for openings, and adding a buffer for wastage.

Step-by-Step Calculation for Bricks

Follow these steps to estimate the bricks required for a standard-size brick wall:

1. Measure Your Wall Dimensions

Begin by measuring the total length and height of the wall or walls you intend to build.

• Formula: Total Wall Area (m²) = Wall Length (m) × Wall Height (m)

2. Calculate the Surface Area

Multiply the measured length by the height to find the total surface area.

• Example: For a wall that is 5 meters long and 2 meters high:
  • Total Wall Area = 5 m × 2 m = 10 m²

3. Account for Openings (Windows and Doors)

Unless you are building a solid wall without any interruptions, you'll need to subtract the area of any windows, doors, or other openings from the total wall area.

• Process:

  1. Measure the length and height of each opening.
  2. Calculate the area for each opening: Opening Area (m²) = Opening Length (m) × Opening Height (m)
  3. Sum up the areas of all openings.
  4. Subtract the total opening area from the total wall area to get the net brickwork area.

• Example (Continuing from above): If the 10 m² wall has one window measuring 1 meter wide by 1 meter high:

  • Window Area = 1 m × 1 m = 1 m²
  • Net Brickwork Area = Total Wall Area - Window Area = 10 m² - 1 m² = 9 m²

4. Estimate Initial Bricks Needed Per Square Meter

A general rule of thumb for a standard-size brick wall is to multiply the net surface area you need to cover by 60 bricks per square meter. This accounts for the bricks and the mortar joints.

• Formula: Initial Bricks Needed = Net Brickwork Area (m²) × 60 bricks/m²

• Example: For our 9 m² net brickwork area:

  • Initial Bricks Needed = 9 m² × 60 bricks/m² = 540 bricks

5. Add for Wastage

It's crucial to factor in wastage due to breakages, cuts, or errors during construction. A common allowance is an extra 10% of the total calculated bricks.

• Formula: Total Bricks (including wastage) = Initial Bricks Needed × 1.10 (for 10% wastage)

• Example: For 540 initial bricks:

  • Total Bricks (with wastage) = 540 bricks × 1.10 = 594 bricks
  • Always round up to the nearest whole number or, ideally, to the nearest full pack size offered by suppliers. In this case, you would likely order 600 bricks.

Beyond Bricks: Estimating Other Essential Materials

While bricks are central, brickwork requires other critical components.

Mortar Calculation

Mortar is the binding agent that holds bricks together. Estimating mortar can be complex due to varying joint thicknesses and mix ratios, but a general guide for standard bricks is:

• Rule of Thumb: Approximately 0.25 cubic meters of mortar are needed per 1,000 bricks for a standard 10mm joint.
• For detailed calculations involving cement, sand, and water ratios, consult specific mortar calculation guides or supplier recommendations.

Wall Ties

For cavity walls (two separate brick "leaves" with a gap in between), wall ties are essential to connect the two leaves and provide structural stability.

• Typical Requirement: Around 2.5 to 4.4 wall ties per square meter, depending on building regulations, wall height, and exposure to wind. They are typically spaced at 900mm horizontally and 450mm vertically in a staggered pattern.
• Always refer to local building regulations for precise requirements.

Damp Proof Course (DPC)

A DPC is a waterproof barrier laid at the base of walls to prevent moisture from rising.

• Calculation: Measured in linear meters, equal to the perimeter of the wall foundation.

Practical Considerations for Accurate Estimates

• Brick Size Variations: The "60 bricks per m²" rule applies to standard brick sizes (e.g., 215mm L x 65mm H x 102.5mm W with a 10mm mortar joint). If you're using imperial bricks, larger blocks, or other non-standard sizes, the bricks per square meter will differ significantly. Always check the specific coverage rates for your chosen brick type.
• Bond Patterns: While the overall area calculation remains the same, specific brick bond patterns (e.g., English bond, Flemish bond, stretcher bond) can slightly influence the number of bricks required due to cuts or half-bricks.
• Professional Consultation: For large, complex projects, or if you're unsure, it's always advisable to consult with a qualified builder, architect, or brick supplier. They can provide precise estimates and valuable insights.

Summary of Brickwork Calculation

Here's a quick reference table for calculating bricks for a standard wall: