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Workers will strip tiles from two curved facades and exposed steel will be painted white until a permanent solution is found.

With tiles falling off its shell-like facades, remedial work started recently to safeguard the eight-year-old Queen Sofia Palace of Arts opera house in Valencia, Spain.

Crews are stripping loose tiles from the two 4,000-sq-meter curved facades and painting the exposed steel white until a permanent solution is found for the centerpiece of Valencia's City of Arts and Science.

The opera house's facades are formed by steel frames covered with metal plate, onto which some 20,000 irregularly shaped, glazed tiles, known locally as trencadís, are attached. Rising over 70 m, the roughly 40,000-sq-m opera house opened in October 2005.

Native architect Santiago Calatrava and the opera house's builders will bear the estimated $4.1 million in remedial costs, says Máximo Buch, the regional government economy minister.

"The mosaic facade … was installed by a construction consortium following extensive, external independent testing regarding the viability and the security of the finish," says a spokesman for Calatrava. The consortium in-cluded Madrid-based contractors Dragados S.A. and Acciona S.A.

The spokesman also confirms that the fix will be done at no cost to the client. "The causes of the failings are still uncertain, and Santiago Calatrava GmbH and the construction consortium have agreed to assist their client CAC S.A. to implement the immediate temporary repairs to ensure the safety of visitors and to minimize disruption to the opera house and also to have a permanent solution in place by Dec. 31," he said.

Engineers at the local Institute of Construction Technology (Aidico) have yet to complete their investigations on behalf of the regional government. However, the inability of the rigid tiling to accommodate movement of the more flexible supporting steel is a possible cause, says an Aidico representative. The south-facing facade is the most exposed to thermal changes and the most affected by the failures. This supports the theory about the likely cause, he adds.