What is Frog in Bricks?
The depression provided in the face of a brick during its manufacturing is called frog in bricks. T he mortar is filled in the frog while laying the bricks in masonry work to help in bonding and acting as a shear key against horizontal loads.
- Depth of frog in a brick 10 to 20 mm
- Frog should be upward.
The important purpose of frog in a brick:
- Frogs also created an extra recess for the mortar, resulting in a stronger bond between bricks ( form keyed joint between brick and mortar)
- To reduce the weight of the bricks, so that the bricks can be laid with convenience.
- The frog indentation also provides a very suitable location to stamp the makers name into every brick produced.
- It also reduced the drying and firing time of the bricks.
Frog should be upward, why?
Bricks containing frogs should be laid with the frog up so that the frog is completely filled with mortar. If the brick is laid with the frog on the bottom, the frog may not get completely filled with mortar. This would make the brick wall only face-shell bedded, which produces less wall strength than full mortar bedding.