Los Angeles sits on some of the most seismically active terrain in the continental United States. Every building here must meet stringent earthquake safety standards. So a common question we hear is: can reclaimed timber be used for structural applications in seismic zones?
The short answer is yes — with proper engineering. Reclaimed timber that has been properly graded and tested can meet or exceed the structural requirements for seismic construction in California.
The key is individual assessment. Unlike new lumber that comes with standardized grade stamps from certified mills, reclaimed timber must be evaluated on a piece-by-piece basis. This typically involves visual grading by a certified lumber grader and, for critical applications, non-destructive testing.
Non-destructive testing methods include stress-wave timing (measuring how fast sound travels through the wood, which correlates with stiffness and strength), resistance drilling (measuring density variations through the cross-section), and ultrasound imaging (detecting hidden defects like decay or voids).
Old-growth reclaimed timber often tests remarkably well. The dense, tight grain of old-growth species like Douglas fir and white oak produces wood that is significantly stronger than modern plantation-grown equivalents. We regularly see reclaimed Douglas fir that grades higher than new Select Structural.
The engineering community is increasingly comfortable with reclaimed timber. Several engineering firms in Los Angeles now routinely specify it for retrofit and new construction applications, provided it comes from a reputable supplier with documented grading procedures.
For homeowners considering reclaimed timber for structural applications, the process is straightforward: work with a licensed structural engineer who is familiar with timber construction, source your material from a supplier who provides species identification and grade certification, and ensure your building permit reflects the use of reclaimed material.