Yes, specific types of engineered plywood panels are considered mass timber.
While the term "plywood" covers a wide range of products, from thin sheets used in furniture to structural panels, certain advanced forms designed for heavy construction applications fall under the mass timber category. As highlighted by the reference:
"Mass plywood panels (MPP), a brand-new mass-timber product created by Freres Lumber in Lyons, Ore., are used throughout the AWP and as the roof for the PFSC."
This statement explicitly classifies Mass Plywood Panels (MPP) as a type of mass timber, demonstrating that not all plywood, but specific, high-performance engineered varieties, belong to this classification.
What is Mass Timber?
Mass timber refers to a category of engineered wood products used in structural building applications. These materials are typically made by laminating, fastening, or gluing together smaller pieces of lumber to create large, strong components like panels, beams, and columns. They offer a sustainable alternative to traditional building materials like concrete and steel, often possessing comparable or superior strength-to-weight ratios.
Mass Plywood Panels (MPP) as Mass Timber
Mass Plywood Panels (MPP) are a prime example of how engineered plywood can be categorized as mass timber. Unlike standard plywood, which may use fewer layers of thinner veneer, MPP is manufactured from a high number of thin, continuous Douglas Fir veneers. These veneers are laid up and pressed into thick, large-format panels, often exceeding the size of typical building components.
This construction process results in panels with exceptional strength, stiffness, and dimensional stability, making them suitable for use as structural elements in buildings, such as walls, floors, and roofs. The reference confirms their use as structural components:
- Used throughout the AWP (presumably walls, floors)
- Used as the roof for the PFSC
Their use in these significant structural applications aligns perfectly with the definition and purpose of mass timber products.
Other Types of Mass Timber
MPP is just one innovation in the growing field of mass timber. Other common types include:
- Cross-Laminated Timber (CLT): Layers of solid lumber are glued together with alternating layers oriented perpendicularly.
- Glue-Laminated Timber (Glulam): Layers of dimensional lumber are glued together with grain running parallel. Used for beams and columns.
- Nail-Laminated Timber (NLT): Dimension lumber planks are stacked on edge and fastened with nails.
- Dowel-Laminated Timber (DLT): Similar to NLT, but uses hardwood dowels instead of nails for fastening.
| Mass Timber Type | Primary Composition | Typical Application | Connection Method |
|---|---|---|---|
| Mass Plywood Panels (MPP) | Multiple thin wood veneers | Walls, floors, roofs | Glued |
| Cross-Laminated Timber (CLT) | Layers of solid lumber | Walls, floors, roofs | Glued |
| Glue-Laminated Timber (Glulam) | Layers of dimensional lumber | Beams, columns, curved members | Glued |
| Nail-Laminated Timber (NLT) | Dimensional lumber planks | Floors, roofs | Nailed |
| Dowel-Laminated Timber (DLT) | Dimensional lumber planks | Floors, roofs | Dowels (Hardwood) |
Why Mass Plywood is Part of the Mass Timber Movement
The inclusion of products like MPP within the mass timber definition highlights the evolution of engineered wood. These advanced plywood panels offer benefits associated with mass timber, such as:
- Structural Strength: Capable of supporting significant loads over large spans.
- Sustainability: Made from renewable resources, often with less embodied carbon than concrete or steel.
- Speed of Construction: Large panels can be prefabricated and assembled quickly on-site.
- Aesthetics: Offers the natural beauty of wood as an exposed finish.
Therefore, while not all plywood is mass timber, specifically engineered panels like MPP are correctly classified as such due to their structural properties, scale, and application in construction.
