Oriented strand board

By 1963, when Armin Elmendorf filed his patent for oriented strand board, the invention was less breakthrough than convergence. Three decades of engineered wood experimentation, wartime scarcity innovation, and adhesive chemistry had created a narrow corridor through which OSB could emerge.

The foundation was particle board, born from wartime desperation. In 1941, Torfit Werke AG in Bremen, Germany began producing pressed wood from sawdust and resin to compensate for timber shortages. The insight was radical: wood didn't need to be solid logs to become structural material. Waste chips bonded under heat and pressure could reconstitute into panels.

Waferboard emerged as the next iteration. In 1963, MacMillan Bloedel opened the first viable waferboard facility in Hudson Bay, Saskatchewan. Larger than particle board chips but randomly oriented, waferboard had acceptable strength but fell short on stiffness—floors bounced, roofs sagged. The problem was entropy: random orientation meant unpredictable performance.

Elmendorf's patent solved this. By aligning wood strands in perpendicular layers—external layers parallel to strength axis, internal layers perpendicular—OSB mimicked plywood's cross-laminated structure without requiring continuous veneers. Plywood had demonstrated directional strength since the 1860s; Elmendorf asked what if we oriented chips instead of peeling logs.

Yet OSB languished commercially for two decades. What changed was economics: old-growth timber became scarce, the spread between OSB and plywood prices widened. By 2000, OSB production exceeded plywood. The cascade was structural: OSB made affordable housing possible by using fast-growing aspen and southern pine, reducing material costs by $700 per typical home. Today OSB commands 66% of North America's structural panel market.