Upper West Side Condo Replaces Terra Cotta Rainscreen with Aluminum Panels

Rainscreens are like a building’s raincoat, helping structures withstand the elements. But they can break down — catastrophically — over time.

Dangerous development. The board at a 34-story condominium on the Upper West Side first sounded the alarm after a tile from its terra cotta rainscreen fell from one of the upper floors and crashed through a paver on a lower terrace. “It was unclear whether it was a broader problem or a localized one,” says Eric Vonderhyde, who was brought on to inspect the building. 

All of the apartments at the condo have floor-to-ceiling windows, and the rainscreen runs horizontally between the floors and vertically between the windows in a cross-grid pattern. The screen is an exterior sheathing that keeps a lot of water out, but not all of it, and the space between the screen and the facade allows the moisture to dry. “The screen also allows the facade to breathe and can heat up in summer or cool down in winter without impacting the exterior and interior of the building,” he explains. Vonderhyde removed the cracked terra cotta tiles and the building was declared safe, but after conferring with the board decided to do additional inspections and testing to determine whether the problem was a flaw in the tile material or something that occurred during transportation or installation.  

Unsolved mystery. The rainscreen system used at this condo was a state-of-the-art terra cotta system from Germany, but when Vonderhyde researched the system in Europe he found that they were used on low-rise buildings. “They were not subjected to super-cold winters or the facade movement that is normal on a really tall building like this condo,” he says. To get to the root of the problem, Bertolini inspected the entire condo for two years, conducting every kind of freeze-thaw testing imaginable. 

But there was no smoking gun. “Surprisingly, we found no material defects whatsoever, but we continued to find a lot of new hairline cracks — which, given the climate in New York, would definitely lead to more falling tiles,” he says. Vonderhyde also found about ten locations where the tiles were hanging by a thread, which meant drastic action had to be taken, and quickly. “Terra cotta is incredibly heavy, so when it fails it does so catastrophically,” he says. “We informed the board that it wasn’t something we could fix and that the whole building needed to be re-skinned.”

Finding the fix. That posed a unique challenge. “We had a proprietary system that we needed to retrofit with something else,” explains Vonderhyde, who considered both aluminum and glass screens. “There were some really nice glass options, but they were prohibitively expensive, so we ended up going with aluminum,” he says. Bertolini partnered with The Garland Company, which makes roofing and building envelope systems, to come up with the custom panels. The existing rainscreen is divided into sections of 12 or 16 tiles, each 12 inches long about 8 or 10 inches high, and the new aluminum panels are the same size. “Because the rainscreen system was designed to support heavy terra cotta tiles, it has a robust substructure with clips, which we wanted to use, since each component costs money,” he says. “The aluminum panels were an ideal replacement since they weigh far less than terra cotta, so the only load on them would be wind.”

The installation cost is $3 million for the replacement alone, which excludes all of the previous testing and inspections. “It’s quite a price tag,” Vonderhyde says. “But the aluminum panels will pretty much last for the life of the building.”