Laminated Veneer Lumber

Summary

Laminated veneer lumber is made by bonding many thin wood layers with adhesives, stronger and more uniform than conventional lumber and much less likely to warp or shrink. It is specified by modulus of elasticity (commonly 12 to 14 GPa) for headers, beams, and rim board, and is not suited to exterior load-bearing use.

Cols

Image

Laminated Veneer Lumber.jpg

LVL: laminated veneer lumber
Micro=Lam: the first commercial LVL (1971)
Rim board / header: common LVL applications
NDS: American Wood Council National Design Specification, first to mention LVL in 1991
Tension lamination: LVL used to strengthen glulam beams

History and demand

Invention

1971: Arthur Troutner introduced Micro=Lam LVL (billets 4 ft wide, 3-1/2 in. thick, 80 ft long) and proved it by building a house in Hagerman, Idaho

First uses in construction

Mid-1980s: LVL became widespread as environmental concerns about logging pushed builders toward engineered lumber
1991: first mentioned in the NDS

Sourcing

North American manufacturers produced more than 1.2 million m³ in 2012 at 18 facilities; output rose more than 14 percent in 2013; many mills are co-located with I-joist plants

Composition and production

Product forms

Up to 4 ft wide and 80 ft long, often cut to match I-joist depths

Properties

Mechanical

Modulus of elasticity: commonly 12, 13, and 14 GPa (about 1.7 to 2.0 million psi)
Allowable bending stress: commonly 19 to 21 MPa (2,800 to 3,000 psi)

Standards

Material specifications

ASTM D5456: structural composite lumber
AWC NDS: design specification, updated every 3 to 5 years

Uses in buildings

Building elements

LVL and PSL: headers, beams, and columns
Wood-Framed Floors, Wood-Framed Walls: rim board, headers, and tall studs
Wood I-Joists: flange material
Flush Wood Doors, Stile and Rail Wood Doors: structural composite lumber cores and engineered stiles

Pros and cons

Pros

Factory-controlled and uniform
Warps and shrinks much less than sawn lumber
Can serve as a tension lamination in glulam

Cons

Not well suited to outdoor load-bearing use because adhesives block the chemical treatments used on outdoor lumber

Manufacturing and cost

Main manufacturers and suppliers

Trade association: APA – The Engineered Wood Association.

Sources

Wikipedia: Laminated veneer lumber, https://en.wikipedia.org/wiki/Laminated_veneer_lumber
UpCodes: 2024 IBC Chapter 23 wood, https://up.codes/viewer/department-of-defense/ibc-2024/chapter/23/wood
Wikimedia Commons: Biegesperrholz 2009.jpg, photo by Elke Wetzig (elya) (CC BY-SA 3.0), https://commons.wikimedia.org/wiki/File:Biegesperrholz_2009.jpg