Enhancing Aesthetics and Performance with Glass Rainscreen Cladding Systems
- Acelab
- Team
Glass rainscreen systems can provide the modern aesthetic and performance levels that allow architects and designers to deliver energy-efficient buildings with expansive walls of glass and light. We’ll explore how design professionals can incorporate rainscreen systems, as well as the design flexibility and performance they offer, to take projects to new levels.
Understanding Glass Rainscreen Cladding Systems
Glass rainscreen systems provide a strong and safe system with design flexibility, thermally efficient insulation, and a weather-resistant facade that stops water from penetrating the interior wall system. It also provides exceptionally attractive, modern and unique exterior façade options.
A glass rainscreen cladding system is composed of exterior glass panels, a gap or cavity between the exterior cladding of a building, a water- resistive barrier (WRB), and insulation. The cavity allows for both water drainage and airflow, which helps to keep the entire wall assembly dry, in order to protect the system from the degradation and mold that often accompanies damp assemblies. Moisture trapped behind cladding or within walls can also lead to poor management of indoor temperatures, which causes greater energy expenditures. With a glass rainscreen cladding system, glass panels serve as the exterior cladding.
Definition and Components of a Glass Rainscreen System
A high-performance glass rainscreen cladding system is an assembled system designed to promote the passive removal of water and water vapor from a building’s exterior. Together, the components of the system help to ensure the integrity and longevity of the building. Three elements come together to provide air and water tightness, exceptional thermal performance, and wind, fire, and blast protection.
The three fundamental components of a glass rainscreen system include an outer layer, an inner layer, and the air space between them.
Outer Layer
The outer layer, or cladding, is the outward-facing element of the system. It protects the building from the elements, such as rain, snow, and sleet, and is the first line of defense for keeping other components of the system dry. While many types of cladding are compatible with a rainscreen system, glass provides an option for sleek, modern and artistic design that is virtually unmatched when compared to other cladding materials. Glass is also a nonporous material that sheds water easily and resists graffiti.
Inner Layer
The inner layer of the system protects the assembly from liquid water, water vapor and moisture buildup, as well as air transfer through the building envelope. Products used in the air space between the cladding and the wall structure are called weather-resistive barriers (WRBs). There are many types of WRBs.
Vapor barriers prevent moisture from transferring through to interior walls. Vapor retarders diminish the transfer of water vapor and prevent air from passing through the assembly to interior walls. Air barriers prevent both air and vapor passage through the building envelope. Different types of structures, and types of insulation used, as well as geographic climates will generally dictate which inner layer is best for a particular project.
Air Space
The air space or cavity between the outer cladding and inner layer is the definitive feature of a rainscreen assembly. The air space enables evaporation and the natural convection process to occur. The rise of hot air and fall of colder air creates natural movement of air within the cavity, to encourage evaporation and help keep the assembly dry.
Types of Glass Used In Rainscreen Cladding
Today, there are a wide variety of glass panels available for rainscreen systems. Glass may be heat strengthened, laminated, or toughened to meet building codes, as well as enameled or coated. Toughened glass is four to five times more durable than standard glass.
Different Design Options and Customization Possibilities
Technological advancements have produced a wide selection of decorative architectural glass options that are ideally suited to rainscreen systems. Colored and patterned glass panels provide options for unique contemporary facades. Direct-to-glass printing provides opportunities for customized exterior designs, and laminated and tempered safety glass options can enhance glass performance features.
Structural Support and Fixing Methods for Glass Panels
For most rainscreens, the support structure is configured from aluminum and stainless steel and is designed to carry the weight of the glass panel system and to resist wind loads.
Most support systems are engineered with adjustable brackets and rails to hold the glass panels, although channel systems are also available. System configurations are available for vertical or horizontal installation methods. A variety of cavity depths are also available from various structural support manufacturers and are designed to meet structural and thermal requirements to meet U.S. building codes.
Advantages of Glass Rainscreen Cladding Systems
Glass rainscreen systems provide advantages that range from visual appeal and high light transmission to reduction of sound transmission and energy efficiency.
Aesthetic Appeal and Architectural Versatility
Beginning with the influences of Mid-Century Modern design, the cultural appetite for sleek architectural elements and high levels of natural light has really gained popularity.
Glass rainscreen cladding systems define the modern facade with clean aesthetics and expansive views, and with their ability to create virtually seamless walls of glass, they afford architects and designers the opportunity to connect the interior building space to the outside world in almost all climates and locations.
Natural Light Transmission and Visual Connection
Glass rainscreen systems help architects and designers produce aesthetically sophisticated designs with broad, sleek facades that bring interior spaces to life with natural light that allows building occupants to connect with outdoor views, all while providing energy-efficient thermal performance.
Thermal and Energy Efficiency Properties
Glass rainscreen systems include thermally efficient insulation that minimizes damaging condensation and reduces heating and cooling expenses. Glass panels for rainscreen assemblies can also be treated with specialty glass coatings, including low-e coatings, to help maintain balanced indoor temperatures while allowing maximum daylight into spaces. Advances in thermal technology and insulating options help keep interiors warm in cold climates and, during summer months, comfortable even when exposed to maximum daylight through full walls of glass.
Weather Resistance and Durability
The “breathing” nature of the rainscreen assembly makes it inherently more weather resistant than many other types of cladding, such as natural stone, brick, wood, and cementitious claddings, all of which can absorb and retain moisture. Porous materials are more susceptible to expanding and contracting, which can result in damaged cladding, especially during freeze-thaw cycles, which results in the need for frequent replacement.
The rainscreen assembly allows components to dry naturally, to avoid the damaging effects of moisture collection. The non-porous nature of glass cladding resists wind, water, and salt spray in coastal climates. The underlying aluminum and stainless steel support system forms a structural link between the supporting wall and the façade which allows the system to absorb wind and transfer dead loads to the supporting wall.
Sound Insulation and Acoustic Benefits
Rainscreen façades provide a greater level of sound insulation than many more traditional cladding systems. Much of the sound resistance results from the non-homogenous structure and diversity of materials in each layer that covers a wide spectrum of sound frequencies. While the amount of transmission decreased depends in part on the configuration of the system and the type of insulation used in the assembly, the air cavity also enhances noise reduction for building occupants.
Construction Applications of Glass Rainscreen Cladding Systems
Glass rainscreen assemblies are one of the most versatile and attractive façade options available in design and construction today. The systems can completely transform the whole building aesthetic with a wide variety of decorative glass options, while also providing ease of installation and maintenance.
Commercial and Office Buildings
Commercial buildings can reach landmark status when designed with glass rainscreen systems. They offer distinctive design advantages with a modern, sleek aesthetic, while also providing enhanced building performance. Building occupants can benefit from improved indoor environmental quality with reduced moisture intrusion and comfortable temperatures. Glass rainscreen systems can provide more light that connects building interiors with nature and improves the work experience for building occupants.
Residential and Mixed-Use Developments
Glass rainscreen systems offer enhanced design options for residential and mixed use environments. Versatile design options help to create a comfortable home ambiance while enhanced noise reduction makes it easy to coexist with more active development areas.
Educational and Healthcare Facilities
Rainscreen construction can deliver design benefits while enhancing occupant satisfaction. Studies show that patients heal faster in quieter environments that include outdoor views. Students learn better in classrooms that are filled with natural light and managed at comfortable temperatures.
Hospitality and Retail Spaces
Designing with rainscreen systems provides the versatility required to reflect the brand and personality of hotels and restaurants, as well as the unique characteristics of modern retailers. The performance features of rainscreen systems can be designed specifically to address the complex requirements of hospitality environments that typically include cooking environments and high-moisture areas.
Cultural and Public Buildings
Glass rainscreen construction can play an important role when designing for high-visibility projects, such as cultural or public buildings. Rainscreen assemblies provide durable performance that can protect and preserve buildings long into the future, by shielding them from the elements to help ensure their structural viability, and extend their productive life.
Considerations for Glass Rainscreen Cladding System Selection
The layers and components of a rainscreen system are all important for optimum performance. The performance of each component must not only be assessed individually, but also as part of the overall system.
Performance Requirements and Building Regulations
Specific requirements must be met for rainscreen construction. Some requirements vary by geographic location and climate zones. Considerations include:
Fire
Smoke
Water
Air
Thermal
Acoustics
For detailed information on specific performance requirements and building regulations, consult the RAiNA Technical Bulletin: Defining Rainscreen Wall Performance.
Structural Considerations and Load-Bearing Capacity
Consideration for structural and load-bearing capacity include:
Static
Dynamic
Cyclical
Wind
Seismic
Gravity
Creep
Deflection
Thermal
Moisture
Impact
Blast
Back-up Structure Movement
For detailed information on structural considerations and load-bearing capacity, consult the RAiNA Technical Bulletin: Defining Rainscreen Wall Performance.
Glass Thickness and Transparency Options
A variety of glass thicknesses are available for rainscreen construction, and some manufacturers will produce custom thicknesses. Thickness must be taken into consideration during the design process to accommodate the impact of weight requirements on the other components of the system, as well as the overall performance of the system. Glass thicknesses vary by manufacturer, but typical sizes include: 0.25 in (6 mm), 0.3125 in (8 mm), and 0.375 in (10 mm).
Glass panels are also available in a wide range of transparency options, including solid or opaque, semi-translucent, or translucent. When full systems are purchased from a single manufacturer, glass thicknesses are limited to accommodate fit with structural components.
Maintenance and Cleaning Requirements
Non-porous glass surfaces are inherently durable. There are no refinishing or resurfacing requirements. The ease of maintenance of non-porous glass surfaces is a significant benefit in contemporary rainscreen applications. There is no better building material to stand up to the punishing effects of water, wind, and time than glass. It also resists stains and graffiti.
Only simple glass cleaning methods are required, so maintenance costs are minimal over the life of the building.
Glass rainscreens in low-rise installations can be spray-hosed.
Depending on the cavity size, it is also possible to clean rainscreen cladding from a catwalk positioned behind the cladding for low and mid-rise installations.
Glass may also be cleaned from inside the building, through windows that open in.
Cost Considerations and Budget Constraints
When compared to other typical façade systems, the rainscreen system offers lower life-cycle costs. The glass rainscreen has features such as minimal maintenance costs, that boost its long-term performance and balance out the initial capital costs of the system when compared to less durable designs.
Installation and Maintenance of Glass Rainscreen Cladding Systems
Installation of glass rainscreen systems can vary greatly in complexity from manufacturer to manufacturer. When all system components are provided by a single manufacturer, a glass rainscreen system can be easy to install, which reduces the need for labor, and saves time and money over other exterior cladding systems.
For complex systems, with components sourced from several manufacturers, or those which require channel installation for glass, a skilled glazier may be required. An experienced commercial glazier can install a channel glass rainscreen system without the need for specialized training.
Pre-Installation Preparation and Considerations
Pre-installation considerations will depend on the type of glass and rainscreen structure specified and will vary from manufacturer to manufacturer. They will also depend on the complexity and customization of the glass rainscreen system being installed.
Manufactures should be consulted regarding pre-installation considerations recommended for their systems, including requirements for maintaining system warranties.
Proper Installation Techniques and Safety Measures
Manufacturer-recommended installation techniques should be followed to ensure that panels are handled properly, including storage of components on the jobsite. Improper installation can result in the voiding of system warranties. All OSHA safety standards should be followed, with specific attention to requirements for installing components on multi-story structures.
Cleaning and Maintenance Guidelines for Glass Panels
Repair and Replacement Options for Damaged Panels
Glass rainscreen panels are relatively easy to replace, if damaged. Most manufacturers offer kits for single-panel replacement that can be ordered to match the original glass cladding. Custom system repairs and replacement may be more complicated, but the overall design of a rainscreen system means that individual panels can be extracted and replaced without needing to remove other system components.
Case Studies: Real-Life Examples
Rainscreen systems are suited equally well for commercial or residential applications and offer design flexibility and opportunities for custom applications that showcase the skill and vision of architects and designers.
3001 Orchard Parkway, San Jose, CA
The rainscreen installation at 3001 Orchard Parkway in San Jose, California created a stunning transformation for an office building retrofit. The project showcases a Bendheim rainscreen system that features approximately 5,000 square feet of laminated safety glass, held by compression glass fittings.
Rainscreen systems are an excellent option for upgrading a building exterior without demolition, or disrupting building occupants.
Davenport House, Louise County, VA
Architect Jeff Davenport chose a glass rainscreen system for his home on Lake Anna in Louisa County, Virginia. The ventilated rainscreen cladding system consists of glass-faced composite panels, thermal insulation, air and moisture barrier, and metal framing. The StoVentec® Glass Rainscreen® system provides a high performance facade with a sleek, elegant look designed to reflect the attractive, surrounding landscape.
Discussing the Benefits and Challenges Faced in Each Case
The two projects featured above demonstrate the versatility of glass rainscreen panels, by showcasing a commercial retrofit and a modern residential application that was the first installation of its type in the U.S. Glass panel rainscreen construction was chosen to provide better insulation, as well as dramatic aesthetics. The system also provides thermal and sound insulation.
For the 3001 Orchard Parkway office transformation, architects were able to create a new façade for the existing building, which resulted in considerable project savings. The application increased both the building value and revenue potential and it was a fast and easy install, coming in at approximately $85 per square foot. The project was recognized as a finalist for the 2014 Silicon Valley Structures Award.
Trust Acelab When Selecting Glass Rainscreen Cladding Systems
Rainscreen systems provide architects and building designers with flexible options to help create beautiful and long-lasting buildings. With virtually unlimited design versatility, rainscreen systems also provide exceptional energy efficiency and performance features that help to ensure an enhanced indoor building environment. Easy and efficient installation methods can reduce the need for labor, which make them cost-efficient options for both retrofit and new construction.
Acelab is a cloud-based collaboration platform that offers a range of tools and resources to help architecture professionals research, compare and select building products for their projects. With Acelab, users can access product data, technical specifications, and CAD details from leading manufacturers, as well as tools to create and manage project libraries, product lists, and specification documents. Acelab is designed to help architecture professionals save time and streamline their workflows by providing a centralized source of information and tools for building product research and specification tasks.
