Relevant standards. The most significant standard by which the performance of vinyl window and door frames should be judged is AAMA/NWWDA 101/I.S.2-97, "Voluntary Specifications for Aluminum, Vinyl and Wood Windows and Glass Doors." This unified standard specifies the minimum performance requirements for windows, regardless of framing material. In order to become certified by the American Architectural Manufacturers Association (AAMA), all windows must meet this minimum standard during testing by an independent third-party laboratory. Certified products meet testing standards for structural adequacy to withstand wind loads, resistance to water leakage, air infiltration, forced entry and other non-mandatory performance requirements. Some of the tests conducted include:
- AAMA Heat Resistance Test: Profiles are exposed to extreme heat (300 F), then measured for resistance to surface degradations like blistering, cracking and delamination. This test indicates any potential surface imperfections in the profile.
- AAMA Weight Tolerance Test: Based on industry-accepted guidelines, this test ensures that finished profiles conform to at least ten percent of the weight of the original design.
- AAMA Dimensional Stability Test: This analysis measures the profile’s linear shrinkage at an elevated temperature (180 F). It is an excellent indicator of internal or residual stresses that may have been induced by the extrusion process.
- AAMA Corner Weld Test: In an additional effort to establish durability, a weight load is applied to test the strength of the weld seam as compared to the body of the profile.
If the profile meets the minimum requirements of the standard, the product receives a certification label which is part of a third-party program accredited by the American National Standards Institute (ANSI). This certification means that the window will perform properly and continuously over a long service life.
For a full list of applicable standards for vinyl windows and glass doors, see "Bibliography."
Code information. Vinyl windows are widely accepted for use in light commercial (low-rise) and residential buildings by model building codes across the country, including codes set by the Southern Building Code Congress International (SBCCI), the Building Officials and Code Administrators International (BOCA) and the International Conference of Building Officials (ICBO).
As noted previously, vinyl framing is typically not specified for heavy commercial (high-rise) windows. The state of North Carolina requires windows to display a label indicating design pressure. This design pressure must be determined in accordance with the provisions of AAMA/NWWDA 101/I.S. 2, and a label from an AAMA-certified product is the preferred compliance option. The new 2000 International Building Code (Chapter 17) and the 2000 International Residential Codes (Chapter 6) both reference the AAMA/NWWDA 101/I.S. 2 performance standard. In these chapters, windows are classified as building components and cladding with accompanying structural provisions for wind resistance. Air penetration and water leakage requirements are also specified.