May 2012
Panels Boost Value And Slash Costs
Insulated composite backup panels provide sustainability while simplifying construction.
Greg Lusty and Scott Bacon, Centria
What is the most effective way for architects, contractors, building owners, and specifiers to deal with long-term exterior-wall performance and energy efficiency while balancing up-front and life-cycle cost considerations? The answer may well be in four simple letters: ICBP_-insulated composite backup panels.
Originally developed as exposed exterior panels for single-element, metal-wall enclosures, ICBPs today can back up various façades, including brick, terra cotta, metal-plate systems, and high-pressure-laminate systems. Their unique structure and ease of installation solve many of the problems inherent in typical multi-component wall-enclosure systems.
Chemeketa Community College, Salem, OR, is a perfect example of ICBP panels used with a mixed-exterior façade. The project used 29,000 sq. ft. of Centria's MetalWrap 100 and 200 series. Photo courtesy of Centria.
For contractors and specifiers, ICBPs not only add to a building's long-term value and contribute to its sustainability, they also add value by simplifying the building process and shortening a project's overall construction schedule.
The ABCs of ICBPs
The composition of an ICBP is simple: insulating foam sandwiched between two formed skins of light-gauge sheet metal. Typically available as 2-inch-thick, R-14-rated panels or as 3-inch-thick panels with an R-20 rating, they differ from metal panels used as exterior cladding on building exteriors. A less dense, closed-cell foam provides thermal insulation, while lighter-gauge metal skins provide an excellent vapor and water barrier.
Because it is not exposed to direct sunlight, the surface coating of the metal skins can have a less expensive finish than an exterior panel. The air barrier is typically the most difficult element to install properly in any wall-enclosure system, but ICBPs feature joints that are effective and relatively quick and easy to install, especially when compared with wraps, self-adhering sheets, fluid-applied barriers, and board-stock insulation.
ICBPs are typically 32- or 36-inches wide, as long as 20 feet, and installed horizontally over 16-gauge metal studs. Horizontal joints are a factory-made, tongue-and-groove configuration and come with a shop-applied, non-curing butyl sealant. Field-applied bed seals at vertical joints are connected to shop-applied sealant in the panel joinery. The result is a complete perimeter seal around each panel. To provide more design flexibility, ICBP systems can be configured to span longer lengths or installed vertically.
Put to the test
Traditional multi-component wall systems (MCWSs) have been used extensively throughout the United States, but they pose numerous problems, particularly related to poor air quality, water and thermal efficiency, and fire protection. While parts and pieces of an MCWS may have undergone industry testing individually, a final assembly may not have been tested as a single unit.
ICBPs address these issues. Those currently on the market meet all water, thermal, air-leakage, and fire-code criteria in mandated codes. More importantly, they have been put through the rigors and scrutiny of industry testing as single units.
According to the National Fire Protection Association, Quincy, MA, ICBP systems provide a continuous and robust thermal barrier tested with various rain-screen assemblies. The design of the panel enhances the wall's fire performance, while the panel-edge design incorporates thermal breaks between the exterior and interior metal skins, creating an efficient thermal barrier between panels.
The new three-year code-revision cycle challenges designers and manufacturers to improve their products and building designs so they continue to meet codes 90.1 and 189.1 of Atlanta-based American Society of Heating, Refrigerating, and Air-Conditioning Engineers on that same three-year cycle. This challenge is met easily by an integrated air- and thermal-barrier solution provided by a single source, such as an ICBP. It is much more difficult to prove that multi-component, multi-manufacturer systems installed and coordinated on site are in compliance with such codes.
Keeping it simple
Testing is critical, but it's not the only factor that makes ICBPs a smarter choice for architects, specifiers, and contractors. The overall value that ICBPs deliver to an entire build team can be described in one word: simplicity. MCWSs involve multiple manufacturers, suppliers, specifications, products, delivery dates, contracts, installers, and warranties, but ICBPs whittle this long list to a single manufacturer and installer.
As a result, an entire project is simplified by dealing with one company, one contract, one component, one supplier, one delivery, one installation crew, one warranty, and one field test. As a value proposition, ICBPs ultimately save time and money for a project-coordination team.
Installation is also more efficient for three reasons:
- Typically only one installation professional is needed to mount an ICBP system. Not only does this decrease labor costs, it also eliminates the difficulties associated with coordinating and scheduling the workers necessary to install a MCWS consisting of exterior sheathing, rigid board insulation, and an air-and-vapor barrier.
- ICBPs can be erected in any climate zone. The air, water, and vapor seal on the liner side of the system has no components requiring certain temperatures for installation. In contrast, spray-foam or spray-on insulation applied on the inside of stud cavities often requires a minimum application temperature.
- All of an ICBP's components (metal skins, foam core, and butyl sealant) are vapor-impermeable, which eliminates risk of internal condensation and entrapped moisture. On the other hand, the use of separate barrier elements in an MCWS means that its design and installation must consider the proper placement of the vapor barrier relative to exterior climate and interior air conditions.
Thermal and moisture protection
Since energy prices skyrocketed in the early 1970s, few construction systems have received more attention from researchers, architects, engineers, and product manufacturers than building enclosures. Before this era of research and innovation began, most wall systems were minimally effective as air and vapor barriers, and only slightly better as thermal barriers. The physics of water and temperature control were poorly understood, and the materials used were relatively crude compared with what we manufacture and install today.
ICBP panels are the result of many years of building scientists working on the long-standing problem of keeping heat in and moisture out. As a result, ICBPs are unique in their ability to provide thermal and moisture protection.
A foam-insulating core provides thermal protection. During the manufacturing process, foam is poured into a panel system in liquid form. Once cured, the foam is encapsulated between two vapor-impermeable steel skins, minimizing any long-term thermal degradation. Traditional board-stock foam, in which foam ages and deteriorates, can allow a wall to lose as much as 20% of its R-value over time. The thermal protection in ICBPs provides a lifetime R-value of 14 or 20, depending on the panel thickness.
The outer skin of a panel serves as the first line of defense for moisture protection. The drain plane, which is made of steel, creates a smooth and durable surface that provides an effective barrier. Shop- and field-applied vertical and horizontal non-curing butyl sealants, combined with pressure-equalized, horizontal panel-to-panel joinery, also provide an effective barrier against moisture.
A sustainable solution
Beyond their extraordinary barrier-wall performance for almost any type of commercial building, ICBPs can contribute to a project's overall sustainability and LEED rating in a variety of categories, such as energy and atmosphere, materials and resources, and indoor environmental quality:
- ICBPs provide an efficient thermal envelope that contributes to the energy efficiency of a building. With high R-value ratings, ICBPs help a building achieve tremendous savings through improved energy efficiency.
- The lifespan of ICBPs is another major contributing factor to their sustainability. Many ICBP wall systems have a long life cycle and require little or no maintenance. Moreover, ICBPs are manufactured with a high percentage of recycled content. The steel face and liner are fully recyclable.
- The fact that ICBPs are composite panels means that less material is used on a project site, which, in turn, leads to less jobsite waste and contributes to LEED points as well as a lower budget for the overall project.
- ICBPs limit the number of deliveries to a jobsite by multiple manufacturers, therefore reducing the total number of vehicle miles on a particular project.
- Since ICBP panels may be installed much faster than multi-component wall systems, it may take significantly less time for contractors to enclose a building structure. As a result, there could be less energy needed to heat or cool a building during the construction phase. Once again, this helps reach sustainability goals and contributes to a healthier bottom line on project costs.
ICBPs in action
So where have ICBPs been put to the test in the field? Three examples of ICBP technology have been used to complete three very different building types: an Alaskan correctional facility, a college health-sciences building, and an outpatient cardiovascular center.
Contractors install ICBPs on the Cardiovascular Consultants building frame. The panel's one_piece construction makes installation simple. Photo courtesy of Centria.
Goose Creek Correctional Center serves as a medium-security correctional center in Wasilla, AK. The architects, KBP Architects, Anchorage, and HOK, Dallas, sought a modern exterior design and wanted to use profiled metal-foam panels for the center, which was to be one of Alaska's largest construction projects.
Due to the harsh Alaskan weather, the architects explored several options before choosing ICBP technology to complement the desired exterior profiled rain-screen system and increase energy efficiency. While designing for the Alaskan environment has its challenges, contractors on the project appreciated that the ICBP technology provided a fast way to get the building dry and insulated without risking damage to the final exterior skin, which was installed later.
Chemeketa Community College's $38.2-million renovation focused primarily on Building 8 of the college's Health Sciences complex in Salem, OR. The 74,000-sq.-ft. project revamped the facilities that house training space and equipment for nursing, dental-hygiene, and pharmacy-technology students.
Sustainability was a major goal of the project, since the building is part of a pilot program with the Energy Trust of Oregon, Portland, OR. For that reason, the architecture firm, SRG Partnership Inc., Seattle, chose exterior building materials that could be insulated for passive ventilation as well as temperature control. The building skin had to provide a high insulation factor and create a tight system that would eliminate airflow exposure. An ICBP wall system was chosen because it not only met the project's sustainability goals, but it was the perfect solution for a building that was using multiple façades, including metal and brick.
The Cardiovascular Consultants medical office building, Cape Girardeau, MO, was designed to enable staff members to provide the most efficient cardiovascular outpatient care. Besides adding much-needed internal upgrades, architects at Medical Design International, Atlanta, aimed to construct a high-performance building with exceptional long-term value.
The installation team chosen for the project, Miller Drywall Inc., Scott City, MO, had never worked with an ICBP system before. However, after a simple training session, the installation team put up more than 1,000 sq. ft. of the product within a few hours. The team maintained this pace throughout the entire project.
Education and exposure
Relatively new to the marketplace, ICBP systems are a culmination of decades of research, development, and know-how about insulated metal panels, as well as application of the same science behind other exterior-cladding systems. As with any new idea or technology, it takes time for industry professionals to understand the overall benefits of ICBP panels and how they are changing prevailing thought about building insulation. Education and research on ICBP projects is key for any build team considering this type of system for their next project. With the potential benefits that ICBP offers, it's worth taking the time to learn about them.
Author
Greg Lusty is foam-product manager for Centria Architectural Systems, Moon Township, PA. Scott Bacon is Centria's global-product and business-development director.
