A misleading statement in that this is only partially true. The movement was not caused by foundation or roof problems. In fact, it was not really a problem at all if the owner had only known the real cause. In north Texas, our summers can be punishing. When outdoor temperatures reach the high nineties, brick walls get very hot and they expand. They not only expand vertically and horizontally, they expand in all directions. This expansion can push the last few bricks closest to the end of the wall. When the temperatures drop, they contract, leaving the few bricks on the end in place. This causes the vertical hairline separation that this home owner saw. Likewise it was not necessary to patch this separated joint with anything, least of all mortar. Adding mortar merely causes further pushing of the column of bricks and makes things worse. Another situation made worse by a well meaning home owner or their repair contractor. To make matters worse, the location of the rain gutter downspout is likely no coincidence.