Burnt Clay Perforated Bricks: 
Perforated Bricks contain cylindrical holes throughout their thickness, have high compressive strength, less water absorption and good thermal insulation. These bricks are light in weight, require less quantity of clay and drying and burning of these bricks is easy and economical. 
Statement (II) is correct. The direction of perforations can be vertical or horizontal. The area of perforations should not exceed 30 to 45% of the area of face. These bricks are used in building walls and partitions in multistoried building construction as they reduce the dead load and cost of construction substantially. 
Statement (I) is correct. IS 2222: 1991 specifies the different properties of burnt clay perforated bricks. From the above explanation it is evident that statement (II) is the correct explanation of statement (I).