Hi, I have a 100+ year old multi-wythe brick cavity wall house where one wall has developed a sizable crack (~1/4"). The crack first appeared when we were saving to replace the retaining wall in the front of our house. The retaining wall was leaning and had no drainage, and needed to be replaced. We had that replaced, and subsequently the backfill has settled and the crack opened up more. It settled during a hard rain.
The crack is a diagonal crack originating at a window corner and going between the bricks. I postulate that the foundation has settled because of the new backfill settling. My hope is that the settling is done, and the crack won't open more. Here's the question: do I just have the crack tuck pointed or do I have to get something else done to shore up the foundation itself? Thanks for the help.

If there is no lateral displacement, meaning the brick is cracked but still in the same plane, then there is no pressing structural issue. The next question is: Is the crack leaking any water? If so, it needsto be fixed, and unfortunately, the place to do that is on the outside of the wall, not the inside. It will need to be excavated, repaired and waterproofed, and backfilled this time with suitable material such as pea gravel or crushed stone.

If it isn't leaking, and it isn't displaced, you can repair the mortar joints if you wish, but be sure to use exactly the right mortar for a 100-year-old wall. It matters. Your masonry yard can probably advise you about what to use.

There is no out-of-the-wall motion. There is no leaking, as far as I can see, there is no spalling or effluence. Neither is there any moisture.

I will continue to monitor the crack for movement and moisture. Thanks for your help.