“Fixing Frank:” Restoration of Fallingwater and Guggenheim Museum
Frank Lloyd Wright's Fallingwater. Photo courtesy of Robert Silman Associates
Solomon R. Guggenheim Museum photo by Wank Adams Slavin Associates LLP
Conservancy President Peg Breen, Robert Silman, founder of Robert Silman Associates, and Andrea Goldwyn, Conservancy Director of Public Policy
Computer imaging of Fallingwater used during restoration analysis. Image courtesy of Robert Silman Associates
Post-tensioned cables used in Fallingwater restoration. Photo courtesy of Robert Silman Associates
Computer image of Guggenheim Museum used during restoration analysis. Image courtesy of Robert Silman Associates
Architects, contractors, and preservationists filled the Conservancy’s conference room to capacity on Jan. 26 to hear noted engineer Robert Silman recap the painstaking analysis and planning process that went into the successful restoration of these two world-famous Frank Lloyd Wright buildings. Silman dubbed the presentation: “Fixing Frank.” This fascinating look at how seemingly unsolvable building problems are overcome through modern engineering techniques was presented so as to be informative and understandable to non-engineers and engineers alike.
Silman’s talk was another in our series of Professional Circle Breakfasts.
Although both buildings are acknowledged as masterpieces of 20th-century design, they were both threatened by serious structural problems. Robert Silman Associates spent several years documenting these structures, analyzing their flaws, and recommending as well as overseeing treatments.
Silman, who is the founder and principle of engineering firm Robert Silman Associates, PC, and a leader in preservation education and policy, understood the responsibility he took on when he was called in to restore what the American Institute of Architects voted “the best all-time work of American architecture.”
“I didn’t want the name Silman to be known as the firm that turned Fallingwater into ‘babbling brook,’” he said.
Deflection in Fallingwater’s projecting terrace appeared right after its construction in 1936. By the time Silman and Associates were charged with repairing the building in 1994, the downward deflection had grown from 1 ¾ to 7 ½ inches. The firm determined after a lengthy monitoring process that an error in design caused a lack of steel reinforcing, which led to the near-failure.
“Really good engineers at the time made a really basic mistake,” he said.
The Silman firm investigated reinforcement options including permanent shoring, supplemental steel framing, bonded steel plating and fiber reinforced laminating before settling on post-tensioned cables set within the interior voids of the concrete cantilever.
“Eight years of work was over in 20 seconds as the new cables were put in high tension by powerful hydraulic engines. Everything came out exactly as predicted,” Silman said.
The second half of the lecture featured Silman’s detailed discussion of exterior restoration at the Solomon R. Guggenheim Museum. Finished in1959 — just prior to the architect’s death — the building is characterized by poured-in-place concrete ramps and walls, and facades finished with Gunite ( a concrete mixture applied by spraying).
After a thorough structural evaluation involving archival research, structural monitoring, laser scans, and crack and tie rod documentation, the firm determined that the Guggenheim suffered from errors in construction.
Among the problems Silman Associates identified were discontinuous horizontal reinforcing bars within the concrete. This fault was remedied through the installation of thin carbon fiber reinforcements on the interior surface of the exterior walls; inadequate dowels were repaired with apron slab brackets. Once the strategy was determined, exterior repairs took one year to complete.
The next Professional Circle event will take place Tuesday, Feb. 2 and will feature an exclusive tour of the Donald Judd House and Studio at 101 Spring Street, which is considered to be the birthplace of “permanent installation” and part of the SoHo Historic Cast-Iron District. Contact Amy Sullivan at 212.995.5260 or to reserve a space.
