Additional thoughts on the NAFS short-form specification

In the December 2014 issue of The Construction Specifier, Dean Lewis wrote about the North American Fenestration Standard/Specification for Windows, Doors, and Skylights’ (NAFS’) short-form specification. American Architectural Manufacturers Association/Window and Door Manufacturers Association/Canadian Standards Association (AAMA/WDMA/CSA) 101/I.S. 2/A440 serves as the basis for product certification as required by the International Building Code (IBC). Due to space constraints, two short ‘mini-articles’ were excluded from the final magazine’s layout. That information is now provided below.

ASTM and AAMA Standards
These are the ASTM standards and test methods cited in the 2011 edition of North American Fenestration Standard/Specification for Windows, Doors, and Skylights (NAFS). (All are assumed to be most current revision level unless otherwise cited.):

  • ASTM E283, Standard Test Method for Determining Rate of Air Leakage Through Exterior Windows, Curtain Walls, and Doors Under Specified Pressure Differences Across the Specimen;
  • ASTM E330, Standard Test Method for Structural Performance of Exterior Windows, Doors, Skylights, and Curtain Walls by Uniform Static Air Pressure Difference;
  • ASTM E331, Standard Test Method for Water Penetration of Exterior Windows, Skylights, Doors, and Curtain Walls by Uniform Static Air Pressure Difference;
  • ASTM E547, Standard Test Method for Water Penetration of Exterior Windows, Skylights, Doors, and Curtain Walls by Cyclic Static Air Pressure Difference;
  • ASTM E987, Standard Test Methods for Deglazing Force of Fenestration Products;
  • ASTM E2068, Standard Test Method for Determination of Operating Force of Sliding Windows and Doors;
  • ASTM F588, Standard Test Methods for Measuring the Forced Entry Resistance of Window Assemblies, Excluding Glazing Impact; and
  • ASTM F842, Standard Test Methods for Measuring the Forced Entry Resistance of Sliding Door Assemblies, Excluding Glazing Impact.

American Architectural Manufacturers Association (AAMA) polymeric profile standards include:

  • AAMA 303, Voluntary Specification for Rigid Polyvinyl Chloride (PVC) Exterior Profiles;
  • AAMA 304, Voluntary Specification for Acrylonitrile-Butadiene-Styrene (ABS) Exterior Profiles Capped with ASA or ASA/PVC Blends;
  • AAMA 305, Voluntary Specification for Fiber-reinforced Thermoset Profiles;
  • AAMA 308, Voluntary Specification for Cellular Polyvinyl Chloride (PVC) Exterior Profiles;
  • AAMA 309, Standard Specification for Classification of Rigid Thermoplastic/ Cellulosic Composite Materials;
  • AAMA 310, Voluntary Specification for Reinforced Thermoplastic Fenestration Exterior Profile Extrusions;
  • AAMA 311, Voluntary Specification for Rigid Thermoplastic Cellulosic Composite Fenestration Exterior Profiles; and
  • AAMA 313, Voluntary Specification for Molded Aliphatic Polyurethane Elastomer Frame Materials.

Design Pressure vs. Performance Grade
In the past, the terms ‘Design Pressure’ (DP) and ‘Performance Grade’ (PG) have been loosely used by some in the field. The specific definitions of these terms have been carefully confirmed with the publication of American Architectural Manufacturers Association/Window and Door Manufacturers Association/Canadian Standards Association (AAMA/WDMA/CSA) 101/I.S. 2/A440, North American Fenestration Standard/Specification for Windows, Doors, and Skylights (NAFS).

Design pressure
Design pressure is a rating identifying the load induced by wind and/or static snow a product is rated to withstand in its end-use application—this is not to be confused with performance grade or structural test pressure (STP). Loads induced by static snow are applicable only to unit skylights, roof windows, and tubular daylighting devices (TDDs).

Performance grade
Performance grade is a numeric designator that defines the performance of a product in accordance with this standard/specification—this is not to be confused with DP or STP. PG is achieved only on successful completion of all applicable tests specified in Clause 5.

Structural test pressure
Structural test pressure is the pressure differential applied to a window, door system, TDD, or unit skylight. In this standard/specification, the STP is 150 percent of DP for windows and doors and 200 percent of DP for TDDs and unit skylights. This is not to be confused with DP or PG.

In other words, DP and STP are strictly structural qualifications, irrespective of the results of any air leakage resistance testing or water penetration resistance testing. On the other hand, the PG of a product is limited by the lowest/least performance of its structural, air leakage resistance, or water penetration resistance test results; operating force and/or forced-entry resistance requirements may also apply.

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