CLT Construction Systems

Role of CLT Within a Structural System

CLT panels may perform one or more structural roles within a building, including:

• Loadbearing walls
• Floor and roof plates
• Shear walls for lateral stability
• Diaphragms distributing lateral loads

The way these roles are combined defines the overall construction system. Unlike framed construction, CLT systems rely heavily on panel action and connection behaviour, making early system selection and coordination critical.

Figure 1: Axonometric Diagram of CLT Construction Systems

Loadbearing CLT Wall Systems

In loadbearing wall systems, CLT panels act as vertical structural elements supporting floors, roofs, and walls above.

Gravity loads are transferred directly through stacked wall panels to foundations or transfer structures. Lateral loads are resisted through CLT shear walls, with floor and roof panels acting as diaphragms to distribute forces between walls.

This system is commonly applied in:

• Mid-rise residential and accommodation buildings
• Hotels and aged care facilities
• Buildings with repetitive layouts and aligned load paths

Loadbearing CLT wall systems offer efficient prefabrication and clear structural behaviour, but they require early decisions on wall locations, openings, penetrations, and service zones.

CLT Floor and Roof Systems

CLT panels are widely used as floor and roof elements, spanning between walls, beams, or columns.

Panels may be designed to span:

• One-way, between parallel supports
• Two-way, where supported along multiple edges

In addition to carrying gravity loads, CLT floors and roofs often act as structural diaphragms, transferring wind or seismic loads to vertical resisting elements such as walls or cores.

Figure 2: CLT During Installation

Serviceability performance, including deflection, vibration, and acoustic response, is often a key design driver for CLT floor systems and influences panel thickness, span limits, and build-ups.

Figure 3: Diagram of they Murray Grove Construction System

Hybrid CLT Construction Systems

Many CLT buildings use hybrid systems, where CLT panels are combined with other structural materials to suit project-specific requirements.

Common hybrid arrangements include:

• CLT floors supported by glulam or LVL beams and columns
• CLT shear walls or cores within steel or concrete framed buildings
• CLT floor plates combined with concrete toppings for acoustic, fire, or structural performance

Hybrid systems allow designers to optimise material use, manage spans and building height, and integrate CLT into broader construction methodologies.

Lateral Load Resistance and System Stability

Lateral stability in CLT buildings is typically provided by:

• CLT shear walls
• CLT cores
• Diaphragm action of floors and roofs

The overall lateral system relies on:

• Panel stiffness and aspect ratio
• Connection strength and ductility
• Load transfer between floors, walls, and foundations

Connections play a central role in controlling system behaviour and are often the governing element for strength, stiffness, and deformation capacity.

Connection and Interface Logic

CLT construction systems depend on well-designed interfaces between:

• CLT panels
• CLT and concrete elements
• CLT and steel framing

Connections must accommodate gravity loads, shear forces, uplift, and differential movement, while also responding to fire, acoustic, and durability requirements. As a result, connection design is closely tied to the selected system typology.

Construction and Erection Considerations

CLT systems are typically characterised by a high degree of prefabrication. Panel sizes, lifting strategies, and erection sequencing are influenced by:

• Transport and crane limits
• Temporary stability requirements
• Site access and program constraints

System selection directly affects construction methodology, including whether the building is erected in a platform-style sequence or through larger panelised assemblies.

Selecting an Appropriate CLT Construction System

The most suitable CLT construction system for a project depends on:

• Building height and structural grid
• Fire and acoustic performance targets
• Speed of construction and prefabrication level
• Integration with other structural materials
• Early coordination between designers, fabricators, and builders

Early commitment to a clear system strategy is critical to achieving the intended performance and construction outcomes.