Facade Inspection Uncovers Hidden Issues, Resulting in Cost-Effective Solution

Some facade issues are trickier to accurately diagnose than others, especially those that aren’t visible to the naked eye. Spending a little extra money to probe deeper — and getting a second opinion — can really pay off.

John Galetta, Principal, Superstructures Engineers + Architects, 
as told to Habitat

Ties that bind. Lincoln Towers, a 30-story, 484-unit co-op at 160 West End Ave., recently had a facade inspection. It’s a cavity wall building where the exterior is a 4-inch layer of brick, an airspace behind it that allows water to run down to the bottom, and a backup construction layer of masonry. After doing probes and opening up a few sections of the building, the engineer found that the wall ties, the thin metal straps that span the cavity and fasten the brick to the masonry to keep the veneer wall from falling off, were present in most of the locations where they were needed, but they were spaced sporadically and farther apart than the 16-inch interval that is required by code. The engineer determined that the brick ties were deficient to the point where the entire building needed to be re-pinned with new ties, which would be a huge $2 million project. Along with other masonry work that was required, including repairing spalling and cracked concrete on the edges of the balconies, the total restoration cost would be $4 million.

Inside job. We were in the middle of a project next door at 170 West End Ave, which was a $600,000 facade restoration. It shares a common wall with 160 West End Ave. and is completely identical. If you look at it from the street, it looks like one enormous building, but it’s actually two separate ones. Because of the cost difference, the board at 160 West End Ave. hired us to do another investigation. My first impression was that re-pinning the entire building was a bit of a broad-brush solution. We performed our own independent probes by dropping scaffolds so we could get our hands on the building, and we did borescope surveys, where we drilled holes through the facade and inserted a camera inside the cavity to check the condition and spacing of the ties. We also used a pulse dive, which is like a metal detector, along the representative scaffold drops and extrapolated the findings so we could map out where all the ties were and made little chalk circles where we found them. 

Reinforcements, not replacements. We were able to identify some patterns. Particular areas, like under the windows, comprehensively did not have ties. Because they’re fairly thin, you rely on the redundancy of these ties to work together to do their job. In other areas, though, the ties were predominantly adequate and in good shape. Also, the facade did not show any of the conditions, like bulging and cracking, that you would find if there was a lack of wall ties. So our solution was to supplement the number of ties by installing more of them at the locations where they didn’t exist. In other words, by acknowledging the overall good condition of the building, we came up with a more realistic scope of work. The original engineer estimated installing about 70,000 ties at a cost of $2 million, but we reduced that to 7,500 ties at a cost of about $200,000.

The takeaway. Engineers are different and they’ll have different opinions. It makes sense to spend a little extra money during the investigation phase to get a better picture of the condition of your building and create a good road map for the contractor to follow. That’s especially important when conditions and potential problems are not visible and you can’t just rely on a visual examination. Doing more on the front end makes a big difference and, as in this case, can save you a very great deal of money on the back end.