By Casey Malmquist, SmartLam
While the construction market continues to support growth of the green building market, with Dodge Data & Analytics reporting the global green building sector will continue to double every 3 years.
This growth also drives continued innovation in green building technologies. One new product in the U.S. called Cross Laminated Timber (CLT) and has proven to be a green alternative to traditional “industrial age” building materials.
This engineered wood building system is made from several layers of dimensional lumber, stacked crosswise and bonded together, providing dimensional stability, strength and rigidity.
Typical structural building components like masonry, concrete, and steel make similar claims but have large carbon footprints. CLT stands out on a number of features, including:
With proper design and maintenance, wood structures can provide long and useful service lives equivalent to other building materials.
Strength and Stability
Cross lamination provides for superior dimensional stability and offers significant shear strength performance at a very unique weight to strength ratio compared to other common structural materials.
Researchers have conducted extensive seismic testing on CLT and found they perform exceptionally well with no residual deformation, particularly in multi-story applications.
CLT panels can be manufactured using CNC equipment to precise tolerances, the tighter-fitting panel joints results in better energy efficiency for the structure. The solid panels also mean nearly zero air infiltration into the building envelope.
A thick cross-section provides valuable and superior fire resistance for a CLT panel.
Moisture Management & Vapor Diffusion
Ideally manufactured at 12% moisture content, wood’s ability to absorb and emit moisture can naturally stabilize an indoor environment. CLT buildings ‘breathe’, minimizing the risk for mold growth and maximizing the comfort of its occupants.
Healthy Indoor Environment
CLT building materials do not introduce any toxins into the indoor environment.
CLT panels are manufactured for specific end-use applications, which results in little to no job site waste.
Wood is the only major building material that grows naturally and is renewable. CLT buildings are easily altered and remodelled, and are also fully recyclable once they reach the end of their useful life.
The versatility of CLT is featured throughout the renovated Star Mill in American Fork, Utah. Reimagined as a mixed-use building, this former flourmill site retains much of its character while embracing the newest building technologies that literally build a bridge to its economic future. CLT panels from SmartLam were used in the flooring structure for the 2nd and 3rd floors of the building. The contractor was so impressed with the ease of installation and visual beauty of CLT, they decided to include CLT flooring systems on the landings of the spiral staircase inside one of the old grain elevators and on the floating deck that spans the main building.
The benefits of CLT also extend to project budgets and timelines. In a multilevel building under construction in Whitefish, MT, the builder specified a CLT elevator shaft. If the construction team was using poured concrete for the shaft, they would have had to budget for a process involving 8-12 people, several inspections, added equipment to form and cure the shafts – and then a month to allow for the shafts to cure in place. The CLT shaft was preassembled in a warehouse and assembled on site with just 3 people and a crane operator. The costs is 70% to 75% of the traditional method.
CLT is proving that sustainable remodelling solutions are stronger, more durable, and more affordable than many presume. A brighter, greener, future is well within reach.