Cross-laminated timber (CLT) has moved from a niche engineered product to a structural system that developers and public agencies specify on schools, offices, and mid-rise housing. That shift depends on manufacturing capacity, and the United States is adding it quickly, with large new production facilities under construction in several states. A typical plant represents a major investment in buildings, processing lines, and workforce training, and its output feeds a construction market that barely existed two decades ago.
For contractors and estimators, the growth of mass timber means new opportunities and new logistics to learn. Understanding how a CLT plant operates, what the material can and cannot do, and how the supply chain is organized is practical knowledge, not background trivia. The construction of the plant itself is a large industrial project, and the crews bringing it online work with the same construction tools and equipment used on any major build.
What Is Cross-Laminated Timber?
Cross-laminated timber is an engineered wood panel made by gluing layers of dimension lumber so that the grain of each layer runs perpendicular to the layer below it. Manufacturers typically build panels from three to nine layers, always an odd number so the panel stays balanced. The crossed grain gives the panel strength in two directions, letting it carry floor and wall loads the way a concrete slab or a steel frame does.
How CLT Panels Are Made
Production starts with kiln-dried lumber, usually spruce, fir, pine, or larch. Boards are graded for structural performance, defects are cut out, and short pieces are finger-jointed into full-length boards. The boards are then face-glued into layers, stacked at right angles, coated with structural adhesive, and pressed under high pressure until the glue cures. Finished panels are machined with CNC routers that cut door and window openings, service penetrations, and connection details before shipment.
CLT panels span roughly 15 to 30 feet in floor applications depending on thickness and loading, and walls rise several stories using panels with engineered openings. Builders pair CLT with glulam beams and columns for longer spans, a combination that produces open floor plans with fewer columns than conventional framing.
Mass Timber Versus Concrete and Steel
The case for CLT rests on measurable differences. A CLT panel weighs roughly a fifth of a reinforced concrete slab of similar capacity, which lightens foundations and lets cranes place larger assemblies. The material also stores carbon: each cubic meter of panel keeps roughly a tonne of carbon dioxide out of the atmosphere for the life of the building. In a fire, thick panels char on the outside while the structural core stays intact for the rated period, which is why CLT buildings meet the same fire-resistance requirements as concrete or steel buildings.
| Property | CLT | Reinforced Concrete | Structural Steel |
|---|---|---|---|
| Relative weight | Light and panelized | Heavy, cast in place | Medium, framed |
| Carbon footprint | Stores carbon | High process emissions | High process emissions |
| Erection speed | Fast, prefabricated | Slow, formwork and curing | Moderate, field connections |
| Fire behavior | Predictable char layer | Possible spalling | Needs fireproofing |
Projects that use CLT still move through the standard phases of design, permitting, and construction. Owners who have managed one structural system can adapt to another, because the discipline of scoping, scheduling, and closeout matches what the construction project life cycle describes for any building.
Designing a Mass Timber Manufacturing Facility
A modern CLT plant is an industrial building in its own right. The facility now rising in Millersburg, Oregon, spans 190,000 square feet and is being built as a full-mass-timber structure, with the building frame made from glue-laminated timber produced at nearby mills. It is designed to produce 7 to 9 million square feet of panel per year and is scheduled for completion by the end of 2026, which will make it one of the largest CLT production sites in the United States.
The project is supported in part by a Wood Innovations Grant from the USDA Forest Service, which funds design work on full-mass-timber buildings. Specifying the plant itself as a mass timber structure lets the design team demonstrate the product the facility will make, a deliberate choice that turns the construction site into a working advertisement for the material.
Facility Size and Layout
Plant layouts follow the production flow in a straight line where the site allows: lumber intake and storage at one end, processing in the middle, and finished panel storage and shipping at the other. The production floor needs high clearances for overhead cranes, wide aisles for forklifts and panel movers, and enough slab area for the press line, the longest piece of equipment in the building.
Key design requirements for a CLT production floor:
- Clear ceiling heights for cranes and tall panel stacking
- A slab engineered for press loads and forklift traffic
- Dedicated zones for lumber storage, layup, pressing, and CNC work
- Dock and rail access sized for panel transport
Production Line Equipment
The processing line is where the investment concentrates. A complete CLT line includes an automated feeding system that moves lumber into the process, high-speed cross-cut saws that trim defects and cut boards to length, and a finger-jointing system that welds short pieces into full-length lamellas.
Automated Feeding and Cross-Cut Saws
Automation matters because throughput is measured in boards per minute, not boards per hour. Feeding systems scan each board, read its grade mark, and route it to the correct station, while cross-cut saws remove knots and splits before boards enter the jointing line. The same scanning data feeds the quality-control records that follow every panel to the job site.
Coordinating the build-out of a plant this size means managing long-lead equipment orders, utility tie-ins, and contractor sequencing, the same challenges that appear on other large industrial construction projects breaking ground around the country. Owners who underestimate procurement lead times find their building finished before their production line arrives.
The CLT Production Process Step by Step
A single panel passes through nine distinct operations between the lumber yard and the loading dock:
- Grade and dry the lumber to the moisture content specified for the product.
- Cut out defects and finger-joint the pieces into continuous boards.
- Face-glue the boards into wide layers called lamellas.
- Stack the lamellas with alternating grain directions.
- Apply structural adhesive to each interface.
- Press the stack under controlled pressure and temperature.
- Let the panel cure until the adhesive reaches full strength.
- CNC-machine the openings, penetrations, and connection details.
- Sand, mark, and package the panel for shipment.
From Lumber to Layup
Quality starts at the sawmill. Structural lumber for CLT is graded and kiln-dried to a narrow moisture range, usually around 12 percent, so panels do not shrink or cup after installation. Finger joints, tested to strict strength standards, let mills use every sound piece of wood, one reason CLT yields so little waste compared with dimension framing.
Pressing, Curing, and Machining
Pressing is where the layers become one element. Hydraulic presses apply even pressure across the full panel face, and the press cycle time sets the plant’s production rate, so manufacturers size their presses to their target output. After curing, CNC routers cut panels to final dimensions and cut openings for doors, windows, and services, which is what makes the panels ready to assemble on site with little cutting.
Most CLT volume goes into commercial and institutional buildings, but the panels work in housing too. Contractors entering the market should study how commercial construction differs from residential construction before bidding mixed-use work.
The Mass Timber Supply Chain
Sourcing Local Timber
A CLT plant is only as reliable as its log supply. The Millersburg facility draws on locally harvested timber, and its building frame comes from glulam produced at other plants in the same region, an arrangement that shortens transport distances and keeps more value in the local economy. Mass timber succeeds where sawmills, dry kilns, and panel plants exist close to one another.
Supply chains in the Pacific Northwest are under pressure, with several mills closing in recent years. New plants are therefore often paired with investments in sawmills and planing mills rather than relying on third-party lumber, because vertical integration gives a panel maker control over grade, moisture content, and delivery timing.
Selecting Structural Materials
Mass timber is not the right answer for every building. Choosing a structural system means weighing cost, spans, fire requirements, and local code acceptance, and the selection, properties, and applications of building materials in modern construction determine which system pencils out.
Jobs, Market Growth, and the Future of Mass Timber
Employment and Rural Economies
A CLT plant is an economic engine for the region around it. The Millersburg facility is expected to create about 100 direct living-wage jobs at full capacity, plus a larger number of indirect jobs in logging, trucking, and support services. Municipalities court these plants because manufacturing wages anchor communities where sawmill closures have cost hundreds of jobs.
Growth Projections and Logistics
Industry figures show mass timber consumption growing from about 11 million board feet across the United States over the past decade toward a projected 3.5 billion board feet within 15 years. Even a fraction of that forecast means more plants, more trailers on the road, and more demand for the heavy haulage and construction logistics services that move oversized panels from factory to foundation.
For contractors, the practical takeaway is that CLT is becoming a standard option with a growing supplier base, and the plants making it are complex facilities in their own right. Every panel that leaves a production line was pressed, machined, and handled by machinery, and the hydraulic power systems that drive heavy construction equipment are the same technology running the presses. Understanding the manufacturing side makes specifiers better buyers and builders better partners.