Masonry wall
This picture shows a parapet masonry wall on a 50-year old building.
No control joint was provided in the brick veneer.
Thermal and moisture movements resulted in the whole upper portion of wall shifted left, and the stepping crack was formed.
Also, note the left corner.
Balustrade posts are piled into steel sleeves embedded in the masonry wall.
Sleeves' tops were sealed and re-sealed as sealant deteriorated, but rainwater penetrated
under coping stones and caused corrosion of steel sleeves.
Rust can expand up to 10 times.
Expanding rust pushed out brick veneer, which eventually fell thirteen flights down.
See the close-up photo below.
I am always surprised by the demonstrated overreliance on a field applied sealant as the only protection against water penetration . In my inspections seal failures account to approximately 95% of all observed facade deficiencies, making the failure almost a sure fact. In this case it resulted in a safety incident.
