Fly ash bricks (Sand Lime Bricks) are Bricks made of Fly ash, Sand, Lime & Cement. It is smooth and uniform in size. It has very low water absorption. More durable as strength increases with passage of time. It is lighter in weight than clay bricks. It also saves morter around 25%. The manufacturing method saves energy, reduces carbon emission, mercury pollution, and costs 20% less than traditional clay brick manufacturing. There are various sizes of bricks.