Engineered Lumber by John Russo Over the past three decades, engineered wood products have made solid, although slow, progress in construction applications. The most common example is plywood. The use of one-inch boards for roof, floor, or wall sheathing would seem archaic today. Plywood itself is now being replaced in some cases by the relatively new particleboards. More sophisticated wood products are being developed at a faster rate than ever before. Each is developed for individual reasons but, in general, the following factors have played a role: 1. To improve the yield from logs. Dimension-lumber production creates large amounts of waste (as much as 50 percent), especially from small logs. The composite and particle products use this waste. 2. The need for specific engineered
