When it comes to masonry issues, the question on when they should be addressed and if it is urgent is often asked. The answer is; the sooner the better. Failing masonry could be anything from loose flagstones coming off of your cement porch, mortar or joints in between bricks failing and requiring tuckpointing to cracking and loose parging (a protective cement layer smoothed over your foundation).
The reason you want to address these issues rather rapidly is simple. The issue is either fixed or gets worse. What I mean by that is that all masonry issues are simply water maintenance issues. Cold frosty winters, salt and other elements take their toll on a home. If this is allowed to re-occur over and over again with out repair- more and more water tends to make its way into cracks and behind bricks causing further deterioration. The issue can become so bad that your bricks start to spall (the face of the brick is seen to practically fall off). The only solution to this being to cut out and replace the bricks and repoint the joints. If you own a home that is much older (100+ years) it will likely be quite difficult to find a good match- so it is always best to get to the problem before this occurs.