One of the most well known by architect Frank Lloyd Wright is undergoing a one-of-a-kind overhaul by a Hanover company. Piece by piece, Structural Group is making repairs to Wright's Fallingwater; a three-story home built incorporating Bear Creek. Without the structural repairs, Fallingwater would end up in the very steam it was designed to embody.

Wright designed and built Fallingwater in northeast Pennsylvania for a private family in 1939. The family later handed the architectural feat over to the Western Pennsylvania Conservancy in 1963. It's design, which perches the house over Bear Creek and includes part of the stream running through the house, has drawn thousands of visitors to the site in the years since.

But that very design also threatened to send the building's terraces into the stream when structural stress started weakening some of the walls and supports. Two of the building's balconies, which hang out over the stream, had started sagging - enough that the tilt was visible to the naked eye, according to James Loper, a structural engineer with VSL, the Structural Group subsidiary handling the renovations.

To preserve the building and prevent it from falling forward even more, Structural Group is in the midst of a three-month process that will reinforce the existing walls and floors without altering the building's look.

"Imagine a diving board in a swimming pool, and that board is made to hang out over the water, to cantilever out and that board has some stiffness to it," Loper said. Over time, the design has proved to not have enough structural support. "So the diving board is no longer stiff enough and it started deflecting down over time. Currently it tilts down 6 or 7 inches over a 15-foot drop, which is very significant."

The Conservancy was tracking the sagging and had installed monitoring devices to track the drooping. "It looked like if we didn't correct the problem the house would end up in the water," Loper said. In the fall, the RFP went out, and by November, Structural Group had won the contract.

Now a team of engineers is installing the cables and support and shoring up concrete cracks to refurbish the house.

Structural Group will run a series of cables between the two levels that make up each floor of Fallingwater, stretching 7-strand cables capable of holding 170 tons each in a grid pattern, called external post-tensioning. Those cables, once attached to concrete blocks, will shore up each level of the house. While the cables won't bring the floors up to their original heights, they will stop the terraces from sagging downward any further.

Structural Group will also patch cracks in the concrete caused by the shifting terraces, injecting epoxy into the cracks. The cracks range in size from hairline fractures to larger cracks. Structural Group will also install carbon rods for added support in the terrace walls.

It's an in-depth process, and because of Fallingwater's historical significance, engineers have to work delicately. "We have to do a lot of hand drilling and cutting with smaller pieces of equipment than what we might normally do," Loper said. Once the project is complete, visitors to Fallingwater won't be able to see the repairs.

Engineers found a surprise when they originally pulled up the stone slab floors to begin the post-tensioning process, Loper said. Part of the structure was deteriorating more than the conservancy and engineers originally thought; therefore, they will be installing more post-tensioning, filling in concrete cracks and replacing some of the floors concrete beams.

The project slated to wrap up sometime this month.

Structural Group is a $132 million revenue company with 1,000 employees and offices in 20 cities across the nation. Founded in 1976, they company and its seven business units have completed more than 40,000 projects, including work on several historical and governmental buildings in Washington, D.C. Still, Loper said the Fallingwater contract is the first contract with such a historical background.