Laminated veneer lumber (LVL) is an engineered wood product that uses multiple layers of thin wood assembled with adhesives. It is typically used for headers, beams, rimboard, and edge-forming material. LVL offers several advantages over typical milled lumber: Made in a factory under controlled specifications, it is stronger, straighter, and more uniform. Due to its composite nature, it is much less likely than conventional lumber to warp, twist, bow, or shrink. LVL is a type of structural composite lumber, comparable to glued laminated timber (glulam) but with a higher allowable stress. History Structural composite lumber products, including LVL, are a relatively recent innovation. They are the result of new technology and economic pressure to make use of new species and smaller trees that cannot be used to make solid sawn lumber. While plywood became widespread by the early 20th century, the invention of LVL was not until the 1980s after the invention of oriented strand board. The American Wood Council's National Design Specification for Wood Construction is generally updated on a 3- to 5-year cycle. The 1991 release is the first release which mentions LVL. LVL is mentioned as a subcategory of structural glued laminated timber. The first explorations into engineered lumber happened during World War II in the United States. In 1942, an increased demand for wood caused a sudden timber shortage. The war industry utilized a panel material developed by the Homasote Company of Trenton, New Jersey, made of wood pulp and ground newspaper, to be used in place of siding and sheathing for buildings. The invention of laminated veneer lumber as known today can be attributed to Arthur Troutner. While glue laminated wood veneers were in use since the middle of the 19th century on a small scale for furniture and pianos, Troutner was the first to develop a laminated veneer lumber of a scale large enough to be used in construction. In 1971 "Micro=Lam LVL" was introduced. "Micro=Lam LVL" consisted of laminated veneer lumber billets wide, thick, and long. Troutner proved the structural capabilities of his Micro=Lam product by building a house in Hagerman, Idaho, using beams made of Micro=Lam. Most corporations considered Troutner's invention to be a niche product and it was not until the mid-1980s when logging became an environmental concern and corporations moved toward engineered lumber that LVL became widespread in use. Qualities Laminated veneer lumber is similar in appearance to plywood, although