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 similar in appearance to plywood without crossbands, and is typically rated by the manufacturer for elastic modulus and allowable bending stress. Common elastic moduli are 1,800,000 psi (12,000 MPa); 1,900,000 psi (13,000 MPa); and 2,000,000 psi (14,000 MPa); and common allowable bending stress values are 2,800 psi (19 MPa); and 3,000 psi (21 MPa).
A comparable material is parallel strand lumber (PSL), which is used in the same applications. Rather than being manufactured from full, parallel veneers, Parallel strand uses veneers with more defects in a more random-looking pattern. Laminated strand lumber (LSL) is another similar type that uses smaller veneers, and so is similar to oriented strand board (OSB) in appearance. Laminated veneer, parallel strand, and laminated strand all belong to the general category of structural composite lumber.
^Allen, Edward and Joseph Iano. Fundamentals of Building Construction: Fourth Edition. Hoboken: John Wiley & Sons, 2004. pg. 91