Two homes after the magnitude-6.0 earthquake in Napa, Calif., in 2014. The one that is not retrofitted was too structurally damaged to be immediately habitable (left) while the retrofitted home next door was structurally sound (right). Credit: California Earthquake Authority3 seismic strengthening elements from standard plan: anchors, shear panels, and angle bracket/ties Old anchors: 1/2 inch, not centered, small washer. New anchor: 5/8 inch, centered, 3X3 bearing plate, 5″ plus deep into foundationStrengthening hardware for ‘bolt only’ installations: anchor plate to secure mudsill to foundation, and angle bracket to secure rim joist (floor) to mudsillCredit: Earthquake Bracing Incorporated
