How to Build a Concrete Block Wall
Step 5: Apply Mortar to Footing
Mortar for a concrete block wall should be workable while firm enough to support the weight of the blocks. Before applying mortar mix to the concrete footing, dampen the surface of the concrete slab with water.
Place a 1” wide bed of mortar on the footing, then use the tip of the trowel to create a furrow in the center of the mortar to distribute it evenly.