The process of repairing missing mortar between bricks is a fairly simple one. The first step is to remove any existing damaged or missing mortar from the area. This can be done with a chisel, mallet, and/or a masonry saw. Once the existing mortar is removed, the area should be cleaned out and any debris removed. Next, a bonding agent is applied to the area to ensure proper adhesion of the new mortar. This also helps to prevent future water damage. The next step is to mix and apply the new mortar. Mortar should be mixed to the manufacturer’s instructions and should be applied in layers of no more than ½ inch thick. Once the mortar is dry, it should be pointed using a trowel and a pointing tool. This process involves pressing the mortar into the joint and smoothing it out. Finally, the area should be sealed with a water-resistant sealant to protect it from further damage and to help keep the mortar in place.