CLT, or cross laminated timber panels are structural panels of 3, 5,7 or more layers glued (at 90 degrees) and pressed together. Their ability to resist high compressive forces makes them cost-effective compared to steel and brick constructions. CLT systems are becoming more popular in the world as they meet complex design and sustainability goals.
Common Applications of CLT Panels
CLT panels provide strength and stability in mid and high-rise buildings. They can be used for residential, commercial or office buildings of up to 8 levels.
Common application of CLT panels include floors, walls, and roofing. They can be also used in balconies, stairs, and even for elevator shafts.
Floors
CLT panels are suited for floor systems as they provide aesthetics and on-site assembly that simplifies the construction process. These panels are shipped to the site and installed in short periods.
Walls
CLT wall panels are a cost-effective solution to pre-cast concrete systems. They are lighter and easier to assemble. Also, when applied together with the CLT floor system, they provide better efficiency and flexibility for different types of building designs. Being a load-bearing element, CLT panels can be used as the structural system for the entire project.
Roofs
CLT roofs can be easily installed on-site, and they can efficiently span up to 12 meters. CLT panels are 5 times lighter than concrete and steel, allowing to create much greater open spaces.
Platform Fame Construction with CLT Panels
The platform frame construction consists of load bearing walls that function as the platform for the next level of construction. Once the walls are braced, the floor panels are positioned onto them and fixed.
Design Considerations of CLT Panels
Acoustic Properties
CLT panels contribute to the overall sound isolation of the completed building. The airtight construction can help reduce sound transmission. This way, the panels require less insulation than other common materials.
Fire Resistance
Researchers confirm that CLT panels provide excellent fire resistance. Due to its nature during a fire, a charred layer forms on the surface of the CLT that creates a barrier. This reduces the entry of oxygen and heat from outside and delays the spread of fire.
Thermal Insulation
Being a solid wood panel, CLT provides a good performance as a thermal insulator. However, the key measures of CLT’s thermal performance relies on the U-Value (coefficient of heat transfer) and R-Value (insulating ability). These characteristics are dependent on the thickness of the panels.
As the panels get thicker, the U-Value decreases and requires less insulating material. As for the R-Value, a common CLT panel (of about 15-20 cm thickness) has about 10 times better insulating value than of concrete and masonry of same thickness.
Airtightness
A good airtightness is achieved through a well-matched contact of surfaces. CLT construction is known for being able to achieve high degrees of airtightness.
Moisture Protection
Cross laminated timber panels are also known as vapor permeable and vapor retardant construction materials. The vapor diffusion resistance value is between μ = 40-80, depending on the moisture content. For this reason, it is much more effective on internal moisture management.