Ping Problem

The Curveball
I’m working on a hundred-year-old structure in downtown Manhattan, solid masonry construction, and I was called in by the managing agent to do some facade repairs. There was a concerning crack on the corner of the building, but nothing that looked out of the ordinary. We put together a standard facade-repair project, drew up the drawings, filed it and got the project going.
In the middle of the project, we found some more concerning issues. The upper two floors of this three-story building were covered in stucco and an Exterior Insulation and Finish System, called EIFS, and we started to remove that and saw that in fact the damage extended beyond the cracks. I called in the managing agent, and we looked at it together. I started hitting the facade with a hammer, which is just a standard way to explore the condition of brick masonry. Instead of the hammer pinging back against a hard, firm surface, the entire wall started vibrating. That wall is holding up the building. It should be very firm and sound, and this one was vibrating up and down an entire floor, which was quite dangerous. You’ve got an entire wall that’s compromised.

The Adjustment
This is actually the only time I've ever done this. We had all of the residents of the building leave that day. The managing agent did an exceptional job of finding them places to stay and working with them. We didn't let them dally at all; they had to leave right away. I notified the Department of Buildings right away, and we had to come up with a new game plan.
The building was in danger of collapsing if we tried to perform the repairs without doing some major shoring. We called in another structural engineering firm, Blue Sky Design, to design some shoring. They're a good engineering firm that we've worked with in the past. They designed some needle shoring, which will actually be steel beams that penetrate through that brick wall and connect to separate steel columns on the inside and the outside. They're working with us to design new supporting foundation systems in certain places, and we’re designing an entire new wall. The longest wall, which the wooden floor framing bears on, is going to be completely reconstructed top to bottom. That's three stories of new wall. So that 100-year-old brick is going to come out, and we're going to replace it with a concrete masonry block.
A challenge that I found an interesting part of this was that we're going to have a patchwork of brick. We're not going to be able to leave this building with exposed brick on all facades because it would look like a patchwork quilt when we're all done. We're actually going to put some EIFS back over top of it to give it a brownstone aesthetic.
The Payoff
An important part of an engineer's job is managing a board's expectations. I try to emphasize at the beginning of projects that there are these potential unknowns going into it. While we are just going to plan for the minimum repairs that are needed, you have to manage those expectations and temper them, understanding that once we get onto a building's facade, there are many things that we could find that we would not otherwise see from the ground or just a single scaffold inspection.
 People on boards have personalities, and there are financial ramifications to these curveballs, which we understand. So managing expectations is part of our job, as much as the math and science of construction. At the end of this project, this old building should look quite nice.