What You Need to Know about 2011 NAFSJanuary 30th, 2012 by DWM Magazine
The American Architectural Manufacturers Association (AAMA), along with the Window and Door Manufacturers Association (WDMA) and the Canadian Standards Association (CSA), has just released the next edition of AAMA/WDMA/CSA 101/I.S.2/A440, also known as the 2011 North American Fenestration Standard (NAFS) for doors, windows and skylights. Already set to be referenced in the 2012 I-codes (the International Building Code (IBC) and International Residential Code (IRC)), the revised standard features several changes. Specifically, one of these has to do with design pressure (DP) and air leakage, according to Ken Brenden, AAMA technical services manager.
Criteria has been added that is specific to Secondary Storm Products (SSP). Performance levels are determined by design pressure for the building’s location range from nominally 15 to 100 psf. The uniform structural load test pressure, applied in both positive and negative directions, is 150 percent of the DP and pressure for the water test (required for externally applied units) is 10 percent of DP. Air leakage test pressure is the same at all performance levels – 1.57 psf. The maximum allowable air leakage rate must be:
• 1.0 cfm/ft of net sash crack perimeter for externally applied operating windows and externally applied fixed removable windows;
• 0.5 cfm/ft of net sash crack perimeter for internally applied operating windows and internally applied fixed removable windows; and
• 1.0 cfm/ft2 of overall frame area for externally applied sliding glass storm doors.
“NAFS-11, the material-neutral guidepost for fenestration specifiers, has been evolving since 1997 and serves as the basis for product certification as required by IBC and IRC,” says Brenden. “Everyone in the industry should be familiar with the requirements of this standard/specification.”
For more on the 2011 NAFS changes, including new requirements regarding lead content for hardware, see the upcoming January-February issue of DWM in the AAMA Analysis column.