Yes, this is a requirement for the new cycle, the ninth cycle. Now, instead of a visual inspection, we’re required to do probes and report on the condition of the wall ties or the absence of ties.ĭo you do the probes during the five-year FISP inspections? Prove to us that it’s not.” So you were guilty until proven innocent, and I say that in a loving way because they were right. The DOB basically said, “We believe cavity-wall construction is in failure. In the last Facade Inspection and Safety Program cycle, the eighth cycle, the Department of Buildings raised the bar on all architects and engineers. How do you discover if there’s a problem? And there have been examples where bricks have fallen off buildings, either as a result of deteriorated wall ties, an insufficient number of wall ties, or just aging.
As you can imagine, if the wall ties are rusting and deteriorated, all of a sudden the bricks can fall off and out. Also, the early building codes required a tie every four feet on center, but later codes required a tie every two feet on center. Meanwhile, the brick on the outside has become more porous, and the galvanized aluminum ties have rusted over time. The problem is that the earlier generation cavity-wall buildings are now 70 years old, and the weak link in the system is not the backup block wall, because that’s on the inboard side, resting comfortably without being subject to wind, rain or any of the elements. They were built from the late ’50s to the 2000s, and they’re all over town. And the brick veneer is tied back to the cement-block with galvanized aluminum wall ties, which keep the brick skin from peeling away and also keep it parallel to the backup wall. Basically, there’s a cement-block wall on the inside, a two-inch air gap, then a brick veneer on the outside. In the 1950s, engineers and architects wanted to come up with a lighter, quicker method of building, so they developed the cavity-wall system.
So in the old prewar days, buildings were built solid mass, three, four, five layers of brick. The Department of Buildings (DOB) is concerned about the safety of buildings built with cavity-wall construction.
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