Is the brick more susceptible to weather damage or does the mortar fail in most cases? The weak link in brick construction may well be the mortar that holds everything together. That being the case, are most waterproofing attempts aimed at bricks or mortar? Does mortar have to be "touched up" from time to time to preserve the integrity of a brick structure?
Of course, it might be that the bricks themselves are more touchy about weather than mortar is.