Red bricks is also called clay soil brick.. Red bricks are not uniform in shape because it is made by hand red bricks is brown in colour.. Compressive strength of red bricks is 35kg/cm2 . Water absorption is more in red bricks 20 %or more. Weight of red brick is 3.2 kg..

Fly ash bricks made by mixing cement slag and flyash uniform in shape cemented colour compressive strength is more than red 75 weight of flyash bricks is 2.6 thermal conductivity is more than red bricks