Why Are Mortar Joints Tooled

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.

What causes mortar joints to crack?

Cracking can result from a variety of problems: differential settlement of foundations, drying shrinkage, expansion and contraction due to ambient thermal and moisture variations, improper support over openings, the effects of freeze-thaw cycles, the corrosion of iron and steel wall reinforcement, differential movement …