content: Making giant beams (the size you could make from these Douglas Firs and not from other trees) is usually not feasible. The tree has too many imperfections, they bend and/or warp when you dry it, have to many knots, etc. Beams taller than about 12 inches are usually some form of engineered wood, most commonly Glued Laminated Timber. They are usually stronger specially in flexure (although they may resist more shear too, depending on the grade) and, more importantly, they are much less variable in their properties and stable in their dimensions. tl;dr plywood is a good material for several uses, big wooden shapes are usually constructed from smaller pieces to reduce variabilities and improve properties.