Laminated Veneer Lumber (LVL)

Laminated veneer lumber (LVL) has several layers of wood veneers and adhesive. First used during World War II to make airplane propellers, it’s been used since the mid-1970's to build beams and headers for buildings where high strength, stability and reliability are required.

To make LVL, dried and graded veneers are coated with waterproof adhesive, assembled in a pattern and formed into billets by curing in a heating press. Afterwards, the billets are cut into stock for headers and beams, flanges for wood I-joists or for other uses. Veneer thickness varies from 0.10" (2.5mm) to 3/16" (4.8mm).  Common species used to make LVL are Douglas fir larch, Southern yellow pine and poplar.

Manufacturers grade the veneers with advanced ultrasonic grading technology or visual grading. Depending on use, ultrasonically graded veneers are strategically located in the LVL for maximum strength.

Finished or architectural grade LVL is available at additional cost.  Common wood finishing techniques can be used to accent the grain and protect the surface.

LVL can easily be cut to length at the job site. The fastening and connection details and requirements are similar to those of solid sawn lumber. However, all special cutting, notching or drilling should be done in accordance with manufacturer recommendations.

Sizes

LVL is available in lengths up to 80 ft. (24.4m), but more common lengths are 48ft. (14.6m) and shorter. LVL is manufactured in thicknesses ranging from 3/4" (19mm) to 2-1/2" (64mm).

The most common thickness used in construction is 1-3/4" (45mm), from which wider beams can be easily constructed by nailing the plies together on site.

Quality Control

The manufacture of LVL requires an in-house quality assurance program — which includes regular, independent, audits by a certification organization are a required part of the manufacturers' quality-assurance program.

LVL products are tested and approved by the major code and product evaluation agencies in the U.S. and Canada. All manufactured LVL products, which have been tested and approved in this way, should bear the seal of the certification agency, manufacturer, date of manufacture, grade and reference to any applicable code or evaluation agency approval numbers.

LVL is a proprietary product having engineering properties that are dependent on the materials used in manufacturing. As a result, it does not meet a common standard of production. Therefore, designers and installers should follow the use and installation guidelines of the individual manufacturers.

Tips

General guidelines for LVL:

• LVL products are available from most major lumber dealers in Canada and the U.S.
  
• Manufacturers' catalogues and evaluation reports are the primary sources of information for design, typical installation details and performance characteristics.
  
• Typical considerations for product specification should include: product availability, product sizes available (i.e. widths, depths & lengths), availability of connectors, engineering and technical support provided by the manufacturer, product quality, product warranty, product acceptance and code approval and installed cost effectiveness.
  
• " LVL should be protected from the weather during job site storage and after installation. Wrapping the product for shipment to the job site is important for protection from moisture. End and edge sealing of the product will also enhance its resistance to moisture penetration.

For more information on LVL, visit:

The APA-The Engineered Wood Association