Shape and size : The bricks should have uniform size and plane, rectangular surfaces with parallel sides and sharp straight edges.
Color : The brick should have a uniform deep red or cherry colour as indicative of uniformity in chemical composition and thoroughness in the burning of the brick
Texture and compactness : The surfaces should not be too smooth to cause slipping of mortar. The brick should have precompact and uniform texture. A fractured surface should not show fissures, holes grits or lumps of lime.
Hardness and soundness : The brick should be so hard that when scratched by a finger nail no impression is made. When two bricks are struck together, a metallic sound should be produced.
Water absorption : should not exceed 20 per cent of its dry weight when kept immersed in water for 24 hours.
Crushing Strenght : should not be less than 10 N/mm2.
Brick earth : should be free from stones, kankars, organic matter, saltpetre, etc.