By Joshua Bowditch
VitrabondG2® Implemented at Ox-Op Gallery and Residences
On the eastern periphery of downtown Minneapolis is the Ox-Op Gallery and Residences designed by Momentum Design Group to harmonize with the historic character of the nearby area. Multiple exterior finishes are used to enhance the aesthetic interest of the architectural design. While mostly clad in fiber cement panels, the building has feature walls of Vitrabond® FR and VitrabondG2® panels. Vitrabond® FR (fire-retardant) is used up to 40 feet above grade and VitrabondG2® (non-combustible) is used above 40 feet height, because of building parameters in consideration with Section 1406.11 of the International Building Code, with no apparent difference aesthetically as there is continuity of the exterior finish. VitrabondG2® is non-combustible as defined by the International Building Code, thereby meeting increasingly stringent building codes that reference the IBC.
VitrabondG2® engineered aluminum panels produced by Fairview Architectural are two sheets of 0.028” aluminum1 bonded to a similarly thin aluminum sheet that is specially contoured as a cross-bracing core2, for a total thickness of 4mm (0.157 inch)1. The core is mostly voids of airspace among the truss-like aluminum internal structure between the two parallel face sheets. The panels use much less aluminum than conventional 1/8” aluminum plate, thereby having the advantages of aluminum but in significantly lower quantity. This is significant considering virgin aluminum is especially energy-intensive to produce3, but aluminum can be considered highly sustainable when used sparingly. Compared to steel, aluminum is stronger and more lightweight. The VitrabondG2® panels are remarkably lightweight at 0.93 lb per square foot1. These panels are an example of dematerialization, the concept of using less material to fulfill an intended purpose. This correlates with less embodied resources and lighter weight load. As another factor to sustainability, the panels have minimal maintenance and outstanding longevity.
VitrabondG2® panels have a polyvinylidene fluoride (PVDF) exterior finish meeting AAMA 2605 performance standards4, providing an exceedingly high level of durability5, and resistance to dirt accumulation because of its fluoropolymer formula3. Fairview Architectural has extensive options regarding the aesthetics of PVDF finishes, and offers architects the opportunity for coordinating custom finishes. The finish is factory-applied by coil coating6, a highly automated and highly efficient process. On a continuous coil coating line, the aluminum sheet is uncoiled, pretreated, primed, coated, cured in finish oven, then recoiled. The continuous coil process minimizes liquid paint waste with nearly a 100% transfer efficiency, and also accommodates controlled collection of volatile organic compounds (VOCs)7. Specifically at Ox-Op Residences the finish is custom Rookwood Red. This is a biophilic warm earth tone color having the color quality of natural and historic material such as brick.
Fabrication and Method of Attachment
Fabrication is a different stage of production by a separate entity, in this case by Atomic Architectural Sheet Metal. Fabrication of panels ready to mount on the wall assembly involves cutting to size, then routing and folding at the perimeter edge to result in a continuous return for attachment of respective panels. Vitrabond® panels can be integrated into various attachment systems available to the building industry, such as the Arrowhead® product line of rainscreen systems by Fairview Architectural. Specifically at the Ox-Op Residences, the ASM D-J (Dry-Joint) system by Atomic Architectural Sheet Metal is used, which consists of intricately small linear aluminum profiles to which the panels attach. It is a route and return system with 1/2” linear gaps as reveals and an overall depth of 1-3/4”. Shown below is a detail of the assembly.
Aesthetically interesting as Ox-Op Residences may be, these aspects would be generally unknown. It is publications like this one that can provide representation of these sustainability aspects through description and illustration. That would be the intent of “Architectural Stewardship”.
This article of Architectural Stewardship was sponsored by Fairview Architectural North America.
1VitrabondG2® Technical Data. 2020. Fairview Architectural North America.
2VitrabondG2® Engineered Metal Plate. 2020. Fairview Architectural North America.
3Ehrlich, B. 2014. Cladding: More Than Just a Pretty Façade. Environmental Building News 23(9): 1-10.
4Vitrabond® Technical Manual. 2020. Fairview Architectural.
5Iezzi, R. A. 2015. Polyvinylidene Fluoride-Based Coatings Technology. In: ASM Handbook, Volume 5B, Protective Organic Coatings. K. B. Tator (ed.)
6Vitrabond® FR Metal Composite Material, Façade System Specification Template. 2016. Fairview Architectural.
7Pilcher, G. R. 2012. Market Analysis Preview: Coil and Extrusion Coatings. In: CoatingsTech. American Coatings Association
About the Author: Josh Bowditch
As a native resident with architectural experience and environmental regard, Josh Bowditch is intent on publishing about sustainability in the architectural and building construction industry locally. From being in the architectural profession, Josh has an understanding of the processes involved. Is it possible to reconcile environmental considerations with development? The word sustainability has various connotations but indeed can be viewed in the context of stewardship. Read previous article.