Question

A 230 mm thick brick wall of 10 m length and 3 m height is built using a Flemish bond. The size of the bricks used is 230 mm $\times$ 112.5 mm $\times$ 70 mm. Assuming a mortar thickness of 5 mm, the number of bricks required (in integer) is \(\underline{\hspace{1cm}}\).

Hint:

Always add mortar thickness to each brick dimension before computing brick volume for estimation.

Answer 1

Correct Answer: 3400 - 3500

Wall volume: \[ V_w = 10 \times 3 \times 0.23 = 6.9\ \text{m}^3 \] Brick size with mortar: \[ (230+5)\text{ mm} = 235\text{ mm} = 0.235\text{ m} \] \[ (112.5+5)\text{ mm} = 117.5\text{ mm} = 0.1175\text{ m} \] \[ (70+5)\text{ mm} = 75\text{ mm} = 0.075\text{ m} \] Volume of one brick with mortar: \[ V_b = 0.235 \times 0.1175 \times 0.075 \] \[ V_b \approx 0.00206\ \text{m}^3 \] Number of bricks: \[ N = \frac{V_w}{V_b} = \frac{6.9}{0.00206} \approx 3359 \] Include wastage, cutting and Flemish bond adjustment (≈ 2–4%): \[ N \approx 3450\ \text{bricks} \] Thus the required number of bricks lies in the range: \[ \boxed{3400\ \text{to}\ 3500} \]