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re: porches in seismic areas

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Forgive my ignorance in seismic design, but regarding porch additions in seismic country many of you report struggling to make them work. Seismic force is directly proportional to the weight of the roof, so a wood framed roof really weighs that much to generate lateral forces that cannot be handled by knee braced posts? You guys want to avoid steel columns, such as HSS posts cantilevered up, but I have used these on residential projects and they are not ALL that expensive. Also, if sticking with wood, is there something against code to embed a wood post in a flagpole like footing, deep enough to resist the overturning and designed to cantilever up to the roof level?
Just curious, also we do a fair amount of small residential stuff and we have to take care of the lateral wind load using similar methods.
Finally, maybe not as "open" of a feel architecturally, but cantilevered reinforced masonry piers if they aren't very tall have excellent resistance to shear, though adding weight in seismic country counts against you...
Andrew Kester, P.E.
Principal/Project Manager
ADK Structural Engineering, PLLC
1510 E. Colonial Ave., Suite 301
Orlando, FL 32803