Concrete form plywood panels are manufactured in conformance with the requirements of the U.S. Department of Commerce Voluntary Product Standard PS 1, Structural Plywood. PS 1 establishes minimum requirements for the principle types and grades of construction and industrial plywood including wood species, veneer grading, glue bond, panel construction and workmanship, dimensions and tolerances, marking, moisture content, quality control and certification.
Concrete form meets the requirements for an "Exterior" bond classification and is manufactured with "B" face and back veneers and "C" or better inner plies. Bond classification is related to the moisture resistance of the glue bond under intended end-use conditions and does not relate to the physical (erosion, ultraviolet, etc) or biological (mold, fungal decay, insect, etc) resistance of the panel.
Class 1 concrete form plywood is designed to provide superior performance in the most demanding applications. A Class 1 panel, as defined in PS 1, is a panel with a Group 1 species in the face veneers, Group 1 or Group 2 species in the crossbands and Group 1, 2, 3, or 4 species in the center plies. A Group number is used to classify species covered by PS 1. Numbers range from 1 to 5. Strength and stiffness properties of species in Group 1 are typically highest, while the strength and stiffness properties of species in Group 5 are the lowest.