What is WIJMA?
The Wood I-Joist Manufacturers Association (WIJMA) is a non-profit organization representing major producers engaged in the manufacture of prefabricated wood I-joists and structural composite lumber (SCL). The purpose of WIJMA is to provide technical assistance and information to the residential and commercial construction industries and to engage in activities that enhance and increase the use of prefabricated wood I-joists and structural composite lumber in the construction industry. WIJMA membership is open to and comprised of technical representatives of prefabricated wood I-joist and SCL producers.
Meetings are generally held twice a year in conjunction with the ASTM-D07 meetings. To address specific issues, WIJMA forms tasks groups made up of representatives of producer and associate members.
Producer Members
Any business entity engaged in the manufacture of prefabricated wood I-joists or structural composite lumber is eligible to become a member of the association. WIJMA is not staffed. Rather, technical representatives of each producer member periodically meet to discuss and address engineering principles, quality control practices, codes, standards, and industry activities. WIJMA’s membership is currently made up of the following producers.
Each producer member pays annual dues and carries equal voting status.
For more information about our producer members and their respective product lines, please click on the links below. See also our Contact page.
- Ainsworth
- Anthony-Eacom
- Boise Cascade
- Georgia-Pacific Corporation
- International Beams
- Louisiana-Pacific Corporation
- Nordic Engineered Wood
- Pacific Woodtech Corporation
- Pinkwood Ltd.
- Barrette Structural
- RedBuilt
- Roseburg Forest Products
- Stark Truss Company, Inc.
- iLevel, by Weyerhaeuser
To become a member, contact Heather Strong at (208) 364-1334 or email hstrong@redbuilt.com.
Officers
WIJMA’s executive board is made up of a President, a Vice President, and a Secretary/Treasurer. Each officer serves a two-year term and is a representative of one of the producer members.
| Office | Officer | Affiliation |
| President | Guy Anderson | Boise Cascade, LLC |
| Vice President | Ben Midgette | Louisiana-Pacific Corp. |
| Secretary/Treasurer | Heather Strong | RedBuilt, LLC |
Associate Members
Any entity engaged in a business or service allied with the prefabricated wood I-joist industry or supportive of it may be an associate member. There are approximately 25 organizations that are currently listed as associate members. At the present time, associate membership is free.
Prefabricated Wood I-Joists
Prefabricated wood I-joists are used throughout the world and are well accepted by the construction industry. Prefabricated wood I-joists are high-strength, cost-effective, and versatile building elements for floor, roof and wall framing in residential and commercial construction. Product lines are manufactured in many sizes, using a number of component materials to obtain a wide variety of engineering design properties.
Prefabricated wood I-joists are specialized products, manufactured with specially designed equipment. Expertise in adhesives, wood products, manufacturing, and quality assurance are necessary ingredients for the fabrication of high-quality prefabricated wood I-joists. Prefabricated wood I-joists utilize the geometry of the “I” cross-section and high-strength components to maximize the strength and stiffness of the wood fiber. Flanges are manufactured from sawn lumber or structural composite lumber, while webs typically consist of plywood or oriented strand board.
The design of prefabricated wood I-joist is efficient at utilizing wood fiber in an optimum manner. The flanges (the top and bottom of the assembled member) are designed to resist bending forces and provide stiffness to the product. The web section is designed to withstand the shear forces in the joist. Adhesive applied in the rout of each flange produces a durable exterior structural joint.
The efficiencies obtained through the use of an “I” cross-section require additional considerations beyond that of solid rectangular sections. The non-rectangular cross-section for prefabricated wood I-joists requires special consideration for end and interior reaction capacity, shear capacity, deflection, connector compatibility, vertical load transfer at points of bearings, web holes, and floor and roof performance.
The unique manufacturing techniques and the variety of materials utilized, result in design values that are typically proprietary to each manufacturer. Prefabricated wood I-joists are tested and qualified under ASTM Standard D-5055 and are recognized in evaluation reports issued by one or more of the model building code evaluation service organizations.
While the growth of engineered wood products (EWP) has been significant during the past 25 years, it is targeted for an even greater growth rate in the coming decade. As the industry matures and grows, technical information of assistance to new manufacturers, builders, designers, and code officials will become even more critical. WIJMA has formed a unique group of technical individuals who work together on common issues that impact their own business as well as the industry. The Association’s proactive membership in industry activities, construction practices, and manufacturing issues has led to numerous projects and activities aimed at enhancing and increasing the use of EWP in the residential and commercial construction industry.