Cantilevers

One of the hallmark features of Falling Water is its cantilevered reinforced-concrete decks, which fly with apparent weightlessness over the rushing water.

After Wright completed the drawings, the client–meaning the guy who not only paid the bills but also planned to live in the house–took the drawings to a professor of engineering at, I believe, Carnegie Mellon. The professor studied the drawings and warned that the decks would fall down. Fortunately, Frank Lloyd Wright managed to convince the client otherwise, and the house was built as designed.

In particular, the deck off the living room was the one in question (the lower deck in the first picture). Here are some views of it.

Years later, structural analysis revealed that the decks were in fact deflecting, with the far ends having sagged about eight inches. Post-tensioning was added to stabilize the structure. The deck has come up a little and is no longer sinking.

A graduate student later analyzed one of the upper decks and revealed that it, too, was beginning to deflect. His calculations were confirmed on site, and that deck too has now been stabilized.

Looks like Falling Water is here for the long run. Thank heavens!