How to calculate refractory brick and castable quantity

Before asking for a quotation, it helps to have a rough idea of quantities. The method below gives a good estimate for planning and budgeting; final quantities should always come from the lining drawing.

Step 1: Work out the lining volume

Multiply the area to be lined by the lining thickness, keeping every dimension in metres. For a flat wall, the area is length times height. For a cylindrical shell, use the mean circumference of the lining: π multiplied by the average of the lining's outer and inner diameters, then multiply by the length.

Step 2: Convert volume to bricks

A standard 230 x 115 x 75 mm brick has a volume of about 0.00198 m³, which works out to roughly 504 bricks per cubic metre without joints. With thin joints of about 2 mm, use around 480 bricks per cubic metre. For other sizes, divide 1 m³ by the volume of one brick including its joints.

Step 3: Add wastage

Add about 5 to 10% for cutting, breakage and shapes. Linings with arches, openings and many cut bricks need the higher figure.

Worked example

A wall 3 m long and 3 m high, lined 230 mm thick. Volume = 3 x 3 x 0.23 = 2.07 m³. Bricks = 2.07 x 480, about 994. Adding 7% wastage gives roughly 1,065 bricks.

For castables

Multiply the lining volume by the castable's bulk density from its data sheet, then add about 5 to 10% for losses. For example, 2 m³ of a castable with a bulk density of 2.3 t/m³ needs about 4.6 tonnes, or roughly 5 tonnes with allowance.

For mortar

Mortar quantity depends on brick size and joint thickness. The data sheet gives a consumption figure, usually per thousand bricks or per square metre of lining.

Get it checked

Shapes, expansion joints, anchors and multiple layers make real linings more complex than a simple calculation. Send us your drawing and we will work out exact quantities along with the quotation.