Mass Ply Panel Certified by APA

Freres Lumber Company is proud to announce that they have received structural certification for their patent-pending product, the Mass Ply Panel, by the APA*- The Engineered Wood Association, under ANSI/APA PRG 320 standards. Freres Lumber is only the third U.S. producer to achieve certification under the standard since its inception, and is the first, and currently only, Mass Timber Panel constructed entirely out of Structural Composite Lumber (SCL) worldwide. SCL encompasses engineered wood products, such as Laminated Veneer Lumber (LVL), covered under ASTM D5456, the standard specification for evaluating SCL.

APA Certified

Mass Ply is an evolutionary leap in many ways—for the construction industry, in the wood products world and in the development mass timber products. By constructing a Mass Timber Panel entirely out of veneer we are not only able to achieve greater minimum design values in equivalent cross sections compared to E2 Cross Laminated Timber (CLT)**, we are also able to design the panels more closely tailored to the end use. We have leveraged our history and experience creating engineered wood products to invent a dramatically different Mass Timber Panel, in terms of product, performance and process.

APA Certified

Mass Ply can make use of small diameter timber to create a large format panel. Our process is uniquely suited to processing the suppressed understory in Douglas Fir stands. Our average block diameter processed to produce our density graded veneers is only 8”, which not only provides the quality engineered veneers we need to make high-performance engineered wood products but provides policy-makers an ideal solution to overstocking in our forests.

APA Certified

We appreciate our partners at the APA who have tested our product from SCL to the Mass Timber Panel. We fully recognize that our testing has only begun as we continue to refine the design values through additional empirical testing. We will also be rolling out additional Mass Ply product configurations as more grades of SCL products (specific veneer layupsindependently verified and certified by the APA) meet approval. We believe that we have benefited from the most rigorous testing ever conducted on a Mass Timber Panel.

APA certified

The news that we have achieved PRG 320 compliance after the culmination of three years of product development, manufacturing design and product implementation is reason to celebrate. We also realize that testing is far from over. In addition to certifying additional products under PRG 320 and ASTM D5456, Freres has already scheduled E84- Flame Spread, and E119- Char Rate, to be completed in September at the Southwest Research Institute. The Tall Wood Design Institute will be completing additional testing in areas such as acoustics, where firm design values are not available.

APA certified

Mass Ply is a uniquely U.S. product, Oregon-developed and manufactured in the Santiam Canyon. Our thanks go to everyone at Freres Lumber who have helped make this happen. We would also like to thank all of our suppliers and contractors who contributed their time and their expertise to our project. This has been a Herculean effort from the beginning. It never would have been possible without our family of contractors, managers and employees who have put their blood, sweat and tears into this project.

The APA Product Report PR-L325 is available at

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* APA is a 501(c)(6) nonprofit trade association that represents U.S. and Canadian manufacturers of structural engineered wood products, including plywood, oriented strand board (OSB), glued-laminated timber (glulam), wood I-joists and structural composite lumber. Its primary functions are product certification and testing, applied research, and market support and development.
**E2 CLT is the most comparable grade of CLT in terms of engineering and species that we must compare Mass Ply to. Engineers and architects should be keying off that field when they are comparing Mass Ply to CLT.


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