Thumb rule - How many bricks are in 1 cum?– LCETED -lceted LCETED INSTITUTE FOR CIVIL ENGINEERS

Feb 8, 2022

Thumb rule - How to calculate the number of Bricks per Cubic meter (Cum) – LCETED

In this article, we explained about thumb rule calculation for brickwork and bricks needed for Cubic meter – cum, before we are going to calculation we have to know the size of the brick to proceed further

SIZE OF THE BRICK

Generally, four standard-sized bricks are used in India.

Which are,

Modular Brick / Metric Bricks – 190 x 90 x 90 mm or 7.48” x 3.54” x 3.54” These are machine-made bricks

Non-Modular Bricks – 230 mm x 110 mm x 70 mm or 9″ x 4.33″ x 2.75″

Conventional Bricks – 230 x 110 x 110 mm or 9″ x 4.33″ x 4.33″

English Size Bricks – 230 x 115 x 75 mm or 9″ x 4.5″ x 3″. (It is usually used in India.)

There are other dimensions depending on the country. The brick weight must not exceed 3 kg.

In this calculation, we will use the English Bricks size

Let’s start,

Thumb Rule for Brick Calculation Per Cubic meter

(OR)

How to calculate the number of Bricks per Cubic meter (cum)

4″ brick wall or single layer or half brick

Size → 230mmx110mmx75 mm (0.230×0.110×0.075 m)

Thickness of mortar = 10 to15mm (0.01m)

By adding the thickness of the mortar

Length of Bricks in meter (L) = 230mm + 10mm = 240mm - 0.240m

Width of Bricks in meter (W) = 110mm + 10mm = 120mm - 0.110m

Thickness of Bricks in meter (T) =75 mm + 10mm = 85mm - 0.085m

Size of the brick with mortar → 240mmx120mmx85 mm (0.240×0.120×0.085) mm

No. of bricks in 1 cubic meter (cum) = Volume of brickwork/ Volume of one brick with mortar.

Volume of brickwork = (Length x Width x depth) of the wall = 1 x 1 x1 = 1cum (to have find per cum)

Volume of a brick = Length of brick x Width of brick x depth of brick

Area of each Brick in Cum= L x W x H = 0.240×0.120×0.085 = 0.002448cum

Therefore,

No. of bricks in 1 Cum = 1/0.002448= 408.496 – 410nos

Considering the wastage percentage as 10% of bricks we will add 10% nos with the total

No. of bricks in 1cum = 410 + 10% = 451nos/cum

Then,

No. of bricks with wastage per cubic meter = 451nos/cum

Thus, thumb rule formula:

How many bricks are in 1cum?

No. of bricks in wall per Cubic meter = (Area in Cum × 451).

How to Use This Thumb Rule?

Let’s explain

Given data:

Size of the 9” brick wall = 3x3m

The thickness of the wall = 9” – 230mm (breadth)

Area of the brick wall = 3 x 3 x 0.230 = 2.07 sqm

No. of bricks in wall per Cum= (Area in cum × 451).

Therefore,

No. of bricks in wall per Cum = 2.07 x 451 = 933.57nos

If you find