Stone Veneer Wall Failure: A Small Earthquake Reveals a Large Problem

November 29, 2009
Publication: Forensic Engineering 2009: Pathology of the Built Environment - Proceedings of the Fifth Congress on Forensic Engineering, Nov 11-14, 2009, ASCE p 33-42

During a recent northern California earthquake of magnitude 4.4, a newly-built hilltop home experienced no structural damage, but some unexpected nonstructural damage. The golden sandstone veneer covering the top portion of an exterior wall dislodged and fell to the ground. The owner hired a consulting engineer to investigate why the damage occurred and how to repair the wall. Given the extent of the stone veneer throughout the house - cladding both exterior and interior walls; in the bedrooms, living room, and kitchen - it became important for the engineer to also determine the extent of the problem throughout the house. The cause of the failure was the contractor's omission of steel wires and dovetail anchors, and the poor bond between the stone and mortar. Repair recommendations consisted of providing supplemental out-of-plane anchorage for the stone veneer.