But things have not quite worked out that way. Water inevitably seeped in, whether through the porous mortar joints between every brick or from behind, and became trapped, prevented by the glaze from quickly evaporating. Then, with the freeze-and-thaw cycles of the New York winter, the water would expand, putting pressure on the glaze, causing cracks and overall deterioration.
“This was actually a ploy to make the buildings quote-unquote more waterproof, and it’s backfired big time,” said Jon Colatrella, the survey team leader at Rand Engineering and Architecture. “Once that moisture gets trapped in between those two materials, essentially, it freezes over time and it just starts to spall and pop and crack that front face right off.”
New York: The Broken Promises of Postwar White Brick Buildings
In an attempt to offer a cleaner and more modern aesthetic, a number of buildings constructed New York during the 50s and 60s used glazed white brick facades. Forensic architect Howard Zimmerman, in an article for the New York Times, claims that the idea came from “the Woodstock era and the Age of Aquarius,” and was intended to create self-cleaning buildings – the glazed coating on the bricks were to repel water.
via nytimes.com