APA - The Engineered Wood Association

Engineered Wood Products for Superior Performance

Engineered wood products are a high-performance, consistent, reliable and environmentally responsible choice for everything from construction to materials handling applications to home projects.

Click on any product in the menu at left or listed below to learn more about that engineered wood product and access links to the APA members who manufacture it.

Glued Laminated Timber (Glulam)

Glued Laminated Timber (Glulam)

An engineered stress-rated product created by bonding together individual pieces of lumber. Can be shaped into forms ranging from straight beams to complex curved members. Used for headers, floor girders, ridge beams and purlins, arches, domes, exposed applications including bridges and utility structures, and much more.
More about glulam.
APA Performance Rated I-joists (PRI)


APA Performance Rated I-joists (PRI) are "I"-shaped structural members comprised of top and bottom flanges, that resist common bending stresses, bordering a web, that provides outstanding shear performance. Used extensively in residential and light commercial construction for both floor and roof framing.
More about I-joists.

Oriented Strand Board (OSB)

Oriented Strand Board (OSB)

Structural wood panels manufactured from rectangular-shaped strands of wood that are oriented length-wise, arranged in perpendicular layers, laid up into mats, and bonded together. Commonly used for sheathing, I-joist web material, upholstered furniture, and many other construction and industrial applications.
More about OSB.



The original structural wood panel. Manufactured from thin sheets of veneers that are cross-laminated for strength, stiffness and dimensional stability. Appearance grades range from smooth, natural surfaces suitable for finish work and underlayment to more economical grades used for wall sheathing, subfloors and siding.
More about plywood.

APA Performance Rated Rim Board

Rim Board

APA Performance Rated Rim Board® works in concert with wood I-joists to deliver a complete framing solution. Rim boards fill the space between the sill plate and the bottom wall plate, or between the top and bottom plate in multi-floor construction, and are an integral structural component that transfers both lateral and vertical forces.
More about rim board.

APA Performance Rated Siding


APA Performance Rated siding lends strength and beauty to residential and light commercial buildings. A single layer of rack-resistant panel siding delivers an attractive exterior appearance while eliminating the labor and materials cost of installing separate structural sheathing or diagonal wall bracing.
More about siding.

APA Specialty Products

Specialty Products

A host of specialty engineered wood products are tailored to meet unique needs in building construction (such as radiant barrier sheathing with reflective surfaces that minimize radiant heat gains) and industrial applications (including furniture frames, pallets, crates, signs, truck and RV bodies, and more).
More about specialty products.

Structural Composite Lumber (SCL)

Structural Composite Lumber

Created by bonding layers of dried and graded wood veneers, strands or flakes with waterproof adhesive into blocks. Solid, highly predictable and uniform, SCL products are sawn to consistent sizes and are virtually free from warping and splitting. Commonly used in headers, beams, rafters, studs, joists, columns and I-joist flange material.
More about SCL.

Related Publications

For your convenience, key APA publications which contain detailed information about the topic that you have selected will be displayed in the right column. You may also wish to browse the Publications section of this website to locate additional publications of interest.

Product Manufacturers

If you are interested in learning more about engineered wood product manufacturers, in the right column of each product page you will find a complete list of APA and APA EWS members who manufacture that product. Click the manufacturer name to learn more.

Member Mills

APA members are comprised of well-known industry leaders, whose mills produce the majority of the structural wood panel products manufactured in North America, plus a host of other products, including glulam, wood I-joists, Rim Board and laminated veneer lumber.

Search Member Mills.


The APA Product Support Help Desk

Contact the APA Help Desk for answers to your questions about engineered wood products and systems. Call (253) 620-7400 or contact us.


Free CAD details from APA at APACAD.org

Visit APACAD.org for more than 250 free CAD details for wood-frame construction.

Publications Index

APA Publications Index, Form B300

Download the free APA Publications Index for a comprehensive list of APA publications.