How do you know when to repoint? Can a wall ever be too far gone to bother with repointing?
Repointing generally is performed for one of three reasons. In older, multiwythe masonry walls, repointing is performed to prevent interior water leakage. Because such walls lack an effective second line of defense such as a drainage cavity, flashing system, or grouted collar joint, they must limit water penetration through the exterior wythe. Water that penetrates the system usually is absorbed or stopped by the multiple wythes of masonry. When water penetration becomes excessive, interior leakage occurs. A second reason to perform repointing is to prevent freeze/thaw deterioration or excessive efflorescence in masonry walls. A third reason for repointing is aesthetic. Repointing can change the color or appearance of masonry walls or improve the appearance of badly weathered joints. Sometimes repointing is not practical. For example, in some chimneys the joints are so badly deteriorated that whole bricks fall from the wall. In these cases it often is more economical to rebuild the chimney.