Rainscreen Systems Utilizing Laminated Engineered Bamboo

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Sponsored by Lamboo Technologies, LLC
By Jessica Jarrard

Rapidly Renewable Resource

Bamboo is one of the most rapidly renewable resources on the planet. It is best harvested when it reaches its maturity in four to five years after initial planting. When it is harvested, the stem is left in the soil to sprout a new shoot and restart the growing process. This is a significant advantage over timber and exotic hardwood production, as they will need to have the entire tree removed and then the ground is reworked to replant another tree. Bamboo also thrives in depleted soil, which means it can be grown in areas where forests have been clear cut or burned. It is also one of the few plants that not only grows easily but can also return nutrients to the soil and reduce soil erosion. Bamboo also grows in areas where other softwoods or hardwoods would have difficulty in growing due to over saturation and unfavorable soil conditions.

Essentially bamboo is a giant grass, comprised of a hollow, tapering culm (stalk) of longitudinally oriented fibers divided by nodes. From the interior to the exterior, the bamboo fibers increase in density. These fibers are essential to creating structural-grade engineered bamboo.

Engineered for Durability

While bamboo is already dense and durable on its own, technological advancements have helped make bamboo an even more reliable rainscreen product. Behind the scenes, manufacturers are discovering ways to boost the performance of engineered bamboo to achieve greater sustainability as well as improved durability, uniformity, and strength. One manufacturing method produces strand-woven or parallel-strand bamboo, made from crushed fiber bundles soaked in resin and treated under pressure to create solid, dense slabs. A second method, known as laminated bamboo, also maintains the longitudinal fibers as the parallel-strand process does, but it also takes advantage of the natural culm matrix. The bamboo stalks are cut and planed, and then processed as desired prior to the lamination and compression in board form. This process typically utilizes less adhesive and tends to provide higher strength-to-weight values.

This means that architects and end users can rely on structural engineered bamboo for longer spans, larger loads, and more extreme conditions. Facilitating these advancements are manufacturing enhancements to make stronger and more durable glulam beams and common dimensional components, as well as hybrid structural solutions and complete systems.

In addition, today’s manufacturers of laminated engineered bamboo panels offer consulting, shop drawings, detailed structural system analysis, engineering, custom three-part specifications, fabrication, and installation advice as needed for their projects. This ensures that designers and architects can specify the right product for the right job.

The strength and efficiency of laminated engineered bamboo, along with the positive carbon footprint of rapidly renewable bamboo, make it a suitable choice for high-performance buildings. The products are also engineered for a high degree of uniformity and consistency, ensuring tolerances within those required for building enclosures and structures.

One of the many benefits is that the engineered bamboo materials have tested to be more stable in climate and temperature changes than engineered woods. Laminated engineered bamboo materials present better mechanical properties over typical natural wood materials, which means they are ideal for window and door products and assemblies. Laminated engineered bamboo functions similarly to hardwoods; however, it has a much better dimensional stability and as a building product can be more sustainably sourced.

Green Building Construction

Not only does the natural product grow quickly, but it is also biodegradable and limits the amount of waste going into the landfill, especially when compared to other building materials such as plastic, aluminum, and stainless steel. Because they are sustainable, strong, and durable, engineered bamboo panels, as well as laminated veneer bamboo materials, are increasingly used for building exteriors and as exposed, load-bearing members. For sustainable buildings and LEED-certified projects, engineered bamboo panels are used for facades, cladding, curtain walls, structural glazing, as well as a range of window and door solutions.

A rainscreen system utilizing laminated engineered bamboo offers more LEED credits than those that use exotic hardwoods and local natural products like cedar and pine. With increased use of engineered bamboo, building projects may qualify for several credits toward LEED v.4 certification, including:

  • EAc2: Optimize Energy Performance
  • MRc3: Sourcing of Raw Materials
  • MRc4: Material Ingredients
  • EQc2: Low-Emitting Materials
  • Inc1: Innovation

Thermal Protection

In addition to providing protection against unwanted air and water intrusion, bamboo is also naturally nonconductive and therefore helps reduce thermal transfer. The conductivity of the bamboo is related to its density. Since engineered bamboo is at a higher density than many equivalent timber products, bamboo can help a building use less energy because thermal energy is not as easily transferred through the engineered bamboo panels. Along with bamboo’s resistance to thermal conductivity, this makes engineered laminated bamboo a material of choice with rainscreen systems. By creating a gap between the exterior wall and the bamboo in a rainscreen system, this helps keep the air temperature behind the rainscreen cooler, which provides overall cost savings in cooling buildings during the summer time heat. This further adds to bamboo’s list of environmental qualities, as energy use and costs will be lower in buildings with laminated engineered bamboo panels.

Considerations Before Installing Laminated Engineered Bamboo Rainscreens

After determining that engineered bamboo panels or laminated bamboo rainscreens are right for your application, it is time to begin the installation process. Another major benefit of engineered bamboo panels and laminated bamboo dimensional components is that they are available in various sizes and lengths to accommodate project requirements. For panels, typical-size panels are 4 feet wide x 8 feet long and available in 12-inch and 34-inch thicknesses. For dimensional components, they are available in lengths up to 20 feet and as wide as 12 inches. Single panels can cover large swatches of the building without needing to be cut.

Some bamboo rainscreen systems also utilize an attachment system that is easy to install and reduces extended installation times and cost, unlike other systems that utilize facade applications. Installing exterior laminated engineered bamboo rainscreens is so easy that occupants can remain inside while panels are being installed.

This section will provide a high-level overview of installation best practices for laminated bamboo rainscreens, including storage guidelines, do’s and don’ts, guidance for the type of fasteners to use, care and maintenance, and an overview of the installation steps.

 

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Originally published in February 2020

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