AC265 - Composite Wood Products
ICC-ES Acceptance Criteria for Composite Wood Products
Last updated: September 21, 2025
Overview
Composite wood products are engineered wood materials made by combining wood pieces (like fibers, chips, or veneers) with adhesives or resins to form a new, solid material. Examples include plywood (thin wood veneer layers glued together), oriented strand board (OSB, wood strands pressed with resin), particleboard and fiberboard (wood particles or fibers bonded into sheets), and even wood-plastic composite decking that mixes wood fibers with plastic.
These products make efficient use of wood resources and can be designed for specific strengths or uses. They are widely used in construction and furniture because they are uniform, stable, and can be made to resist issues like warping or moisture better than some solid wood, as long as they meet the necessary quality standards. See related guidelines for wood structural panels (AC266) for sheathing applications.
Purpose
This acceptance criteria provides a basis for evaluating composite wood products that may not be directly covered by existing codes. It establishes testing protocols, structural performance requirements, and quality standards needed for code approval of these engineered wood materials.
Benefits of Compliance
- Nationwide acceptance by building officials for engineered wood products
- Streamlined approval process for composite wood materials
- Third-party verification of structural performance and quality
- Enhanced marketability for plywood, OSB, and other composite products
Resources
Frequently Asked Questions
What types of products fall under AC265?
AC265 covers engineered composite wood products including plywood, oriented strand board (OSB), particleboard, fiberboard, and wood-plastic composites. These are materials made by combining wood pieces with adhesives or resins to form solid panels or boards.
How does AC265 differ from AC266?
AC265 covers general composite wood products used in various applications, while AC266 focuses specifically on wood structural panels (plywood and OSB) used for wall, roof, and floor sheathing. AC266 has additional structural performance requirements for shear wall and diaphragm applications.
Do I need an ESR for composite wood products?
If the product is not covered by an existing product standard recognized in the building code, then an ICC-ES Evaluation Service Report (ESR) based on AC265 can demonstrate code compliance and gain acceptance from building officials.
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