Aesthetically speaking, mortar joint tooling produces the joint profile in brick walls. ... Proper tooling increases resistance to water penetration along the wall. The “jointer” tool compresses the mortar against the unit, helping seal any separation cracks that might form at the interface.

When should mortar joints be tooled?

Ridges form as the wet mortar sticks to the tool. Joints are not properly compacted if tooled when they are too stiff. These joints must be aggressively worked and often have a darker appearance in the completed wall. Joints should be tooled when they are just stiff enough to support a thumbprint for best compaction.

Why are the joints in a concrete block wall tooled?

Mortar joints play a significant role in masonry walls as they primarily hold unreinforced masonry walls together and transfer structural/thermal loads. Different forms of mortar joints—concave, flush, raked, beaded, struck, and weathered—can be employed in the construction of masonry walls.