Repair cracked mortar on an exterior brick wall with this easy to follow ‘how to’ guide. Clear away any loose mortar from the damaged area using a cold chisel. Place the point of the chisel at the line where the brick meets the mortar, angled toward the center of the joint between the bricks. Hit the head of the chisel sharply with the hammer to chisel away the mortar within the joint to a depth of about 1 inch, or to the depth of the crack if the crack runs deeper than 1 inch.
Mix the replacement mortar in a bucket using an electric drill with a paddle drill bit attachment. Add water to the mortar mix until you create a mortar with the consistency of pudding. Add a small amount of liquid latex binder to the mix to aid the new mortar's adhesion. Use the binder manufacturer's instructions to determine mixing ratios within your mortar mix.
Wait about 15 minutes for the mortar to begin to set. Run a joint strike tool over the joints to remove excess mortar, to pack the surface tightly and to create clean-looking joints between the bricks.