• How they are made?

Fly ash bricks are made from the mixture of fly ash, cement, sand, lime, and gypsum. Industries using coal as a fuel emits unwanted ash and smoke from which fly ash is produced. This fly ash is then used as a raw material for manufacture of bricks.

Red bricks are made by mixture of clay, sand, lime, iron oxide and magnesia. Sand from locally available natural soil is used for production of bricks.

• Strength

Strength of red bricks can vary significantly but it is generally around 70 - 75 kg/cm2. Fly ash bricks have more consistency in their strength and they also have a similar compressive strength of 100 - 110 kg/cm2.

• Quality Consistency

In the case of red bricks, the consistency in quality is not very high. In case of fly ash bricks, the quality is consistent if bought from a good vendor.

• Thermal Insulation

When compared to red bricks, fly ash bricks absorb less heat which causes less heating of structures. Their thermal insulation is 25% - 30% higher than that of red bricks. Thermal conductivity of Red Bricks is 0.6 – 1.0 W/m K while Fly Ash Bricks have a thermal conductivity of 0.3 – 0.4 W/m K.

• Appearance/Wall Finish

Red bricks have an uneven appearance with one side smooth and one side rough, requiring a layer of finishing to give out a smooth surface. On the other hand fly ash bricks have a smooth, even surface on both sides. Hence, they require less plastering for building work.

• Environment Friendly

Manufacturing of red bricks requires extraction and exploitation of the topsoil which may or may not be replaced. Fly ash bricks, on the other hand, utilize a waste material for manufacturing and prove more environmentally friendly. The utilization of fly ash bricks results in conservation of natural resources as well as protection of environment.

• Termite Resistance

Red bricks are made of clay and are more susceptible to termites. In the case of fly ash bricks, they are made of inorganic material and are resistant to termite infestation.