Fallen Arches by Wm. Ward Bucher Masonry walls are most likely to fail around the top of window and door openings. This may be because of beam failure, but it probably is a case of arch failure. Arches as first used by the Romans rarely failed, because they were semicircular. But as square windows and doors became fashionable, there were more and more arch problems. The flatter an arch is, the more likely the top of the arch fall downward. Typically, they will jam in the opening after moving 1/4 inch or so. If the abutments continue to spread, however, the bricks may fall out. Jack arches are particularly susceptible to this kind of failure. In a jack arch, the bottom
