In 2005 and 2009, respectively, the American Aluminum Manufacturer’s Association published test standards AAMA 508 and AAMA 509 for use in determining the performance of cladding systems designed to the rainscreen principle. Without laboratory testing to one of these standards, design professionals and owners are left to rely upon best guesses as to how each will actually perform. Cladding manufacturers and fabricators are beginning to test their systems to these standards, and requirements for this testing are beginning to find their way into designers’ construction documents as well.