Brick sizes

A brick count is the wall area divided by the face of one brick plus the joint you will actually lay. Drop the joint and the count goes up, because you have pretended the units touch. Use a 10 mm joint on a US modular brick and the count is close to the 3/8 inch joint, and still not the same joint. This page puts the bare face and the 10 mm face side by side, and it marks the one US row that this site’s calculator does not treat as 10 mm. The wall, the waste, and the mortar stay on the calculators.

India, from IS 1077

IS 1077:1992, clause 6.1.1, says the standard modular size of common building bricks shall be 190 × 90 × 90 mm and 190 × 90 × 40 mm. Clause 6.1.2 says the non-modular sizes 230 × 110 × 70 mm and 230 × 110 × 30 mm may also be used. The foreword ties the preferred size to a 100 mm module. The standard’s text that was read does not itself say “use a 10 mm joint.” The 10 mm joint is how this site’s calculator turns a 190 mm brick into a 200 mm face module: 190 + 10 = 200, and 90 + 10 = 100. One leaf of the 90 mm brick is 90 mm thick. There is no joint through that thickness, so it is not a 100 mm wall.

With no joint, 190 × 90 mm is 58.48 per square metre and 5.43 per square foot. With the 10 mm joint the module is 200 × 100 mm: 50.00 per square metre and 4.65 per square foot. Those with-joint figures are the India modular row on the brick calculator.

The non-modular face the calculator uses is 230 × 70 mm, the height from the 230 × 110 × 70 unit. Bare, that face is 62.11 per square metre and 5.77 per square foot. Plus 10 mm it is 240 × 80 mm, 52.08 per square metre and 4.84 per square foot. The 40 mm and 30 mm heights are in the standard. They are thinner units, and they are not the rows the calculator menu is using.

The traditional 9 × 4.5 × 3 inch brick

Pakistan and India both still sell a brick the calculator calls 9 × 4.5 × 3 inches, which is 228.6 × 114.3 × 76.2 mm. A Pakistan national brick-size PDF was not opened, so this page does not attribute that size to a Pakistan standard. It is the size the Pakistan brick calculator and the India traditional row both use. The face that sets the count is 9 inches by 3 inches. The 4.5 inches is the thickness of one leaf.

Bare, 228.6 × 76.2 mm is 57.41 per square metre and 5.33 per square foot. With a 10 mm joint, 238.6 × 86.2 mm is 48.62 per square metre and 4.52 per square foot. A 4.5-inch wall is one leaf, so a 10 by 10 foot wall on the Pakistan page is 451.70 bricks, 4.52 per square foot, and the order with 5 percent waste is 475. A 9-inch wall is two leaves plus one 10 mm collar joint: 228.6 + 10 + 228.6 = 238.6 mm, which is 9.39 inches, not a solid 9 inch block. The same 10 by 10 feet is 903.40 bricks, 9.03 per square foot, and the order is 949. Cement on that 9-inch wall at 1:6 is 3 bags of 50 kg, and sand is 18.51 CFT. The per-square-foot column in the table below is one leaf. Double it, and add nothing for a second face joint, when the wall is two leaves.

Square feet in that table are the per-square-metre count times 0.09290304, then two decimals. The with-joint India, traditional, and UK figures are the calculator’s single-leaf table. The bare-face column is the same face with the joint set to zero.

United Kingdom

The UK line is 215 × 102.5 × 65 mm. A current British Standard was not opened, so this is the menu size, not a quotation from BS EN 771. Bare, the 215 × 65 mm face is 71.56 per square metre and 6.65 per square foot. With a 10 mm joint it is 225 × 75 mm: 59.26 and 5.51. One leaf is 102.5 mm thick.

United States

Brick Industry Association Technical Note 10, Table 1, specifies a modular brick as 3-5/8 × 2-1/4 × 7-5/8 inches (92 × 57 × 194 mm) with a 3/8 inch (9.5 mm) joint. The nominal size is 4 × 2-2/3 × 8 inches. Table 4 estimates 675 per 100 square feet, 6.75 per square foot, from that nominal 8 by 2-2/3 inch face.

This site’s calculator adds the 3/8 inch joint to the specified face: 7.625 + 0.375 = 8, and 2.25 + 0.375 = 2.625, which is 2-5/8 rather than 2-2/3. That face is 6.86 per square foot and 73.81 per square metre, the US row in the calculator. Use 6.86 for an order from this site. Use 6.75 when you are copying Table 4. A 10 mm joint on the same specified face is 73.12 per square metre and 6.79 per square foot, because 3/8 inch is 9.5 mm, not 10 mm. The calculator will not produce the 10 mm figure while the US joint stays at 0.375 inch. With no joint the specified face is 90.35 per square metre and 8.39 per square foot.

A wall, not a square foot

The worked wall is 10 m by 3 m, one leaf, 10 mm joint: 1,500.00 bricks, and 1,575 with 5 percent waste. The leaf is 2.70 m³ at 90 mm, which is 555.56 bricks per cubic metre. The 500-per-cubic-metre shortcut assumes a joint through the thickness, so it overstates the mortar for this wall. At 1:6 the joints are 0.12 tonnes of cement, 3 bags of 50 kg, and 0.49 m³ of sand.

A room is four walls minus the openings, on the room calculator. The default 12 by 10 foot room, 10 feet high, with a 3 by 7 door and a 4 by 4 window, in 9-inch traditional brickwork, is 3,640.72 bricks, order 3,823, 11 bags, and 74.59 CFT of sand. Openings come off the area first. Pick the brick, the joint, and the leaves, then use the calculator for that wall. Mortar taken as a percent of wall volume, which this joint method does not use, is the mortar calculator.

Sources

• IS 1077:1992, Common Burnt Clay Building Bricks. Clause 6.1.1 modular sizes 190 × 90 × 90 mm and 190 × 90 × 40 mm, and clause 6.1.2 non-modular sizes 230 × 110 × 70 mm and 230 × 110 × 30 mm.
• Brick Industry Association, Technical Note 10, Dimensioning and Estimating Brick Masonry. Table 1 modular specified size and 3/8 inch joint, and Table 4’s 675 bricks per 100 square feet.
• The 10 mm counts, the bare-face counts, and the US 6.86 figure are this site’s brick calculator and the face arithmetic above. The UK 215 × 102.5 × 65 mm size and the 9 × 4.5 × 3 inch size are the sizes those calculators use. A current British Standard and a Pakistan national size standard were not opened.

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