Final answer:
Repointing or tuckpointing is a common repair method for deteriorated mortar joints.
Step-by-step explanation:
When mortar joints deteriorate, one common repair method is called repointing or tuckpointing. This involves removing the deteriorated mortar and replacing it with fresh mortar. To do this, the old mortar is carefully chiseled out, leaving a clean and sound cavity. Then, new mortar is mixed and applied to fill the gap, matching the color and texture of the existing mortar.