FAQ's

NAFS-08 & 2011 BC Building Code for Door Prehangers

Introduction

WDMA-BC’s continuing series of members’ meetings to discuss and offer information on issues affecting the industry included a very informative session held on October 19th, 2010.

This meeting was well attended, and we were pleased to see several prospective new members show an interest.  In the follow up to this meeting, the WDMA-BC was asked to prepare a brief ‘FAQ’ to assist prehanger members, in particular, understand the upcoming Building Code requirements and ways in which compliance can be demonstrated.

Stay tuned for a fuller report from the WDMA-BC Side Hinged Door Task Group. Members interested in the activities of the task group can contact Zana Gordon 778.887.8843

Please note: This brief FAQ is intended for informational purposes only, and is not intended as an interpretation of code requirements.

FAQ RE: NAFS-08 / 2011 BCBC

Q: What is NAFS-08?

A: NAFS-08 is the latest (2008) version of the AAMA/WDMA/CSA 101/I.S.2/A440 standard, better known as the North American Fenestration Standard 2008 (NAFS-08). It applies to window, door, skylight and roof window products sold in Canada and in the US. Additional requirements that apply to Canada only are found in the Canadian Supplement to NAFS, A440S1-09.

Q: What is the Canadian Supplement?

A: The supplement is a companion document to NAFS that describes Canadian performance and labeling requirements which differ from those in the US. It also contains additional tests that Canadian products must meet. To comply with NAFS in Canada, you need to refer to the Canadian Supplement as well.

Q:  Do exterior doors need to be tested for air leakage, water infiltration and structural performance?

A:  The draft 2011 B.C. Building Code, expected to be in effect as of fall 2011, includes the requirement that exterior side hinged doors comply with the minimum performance levels in NAFS-08. This is, essentially, the first time performance test data will be a code requirement for exterior side hinged entry doors.

Q:  Can a prehanger use someone else’s test data?

A:  Yes. However, it is the responsibility of the prehanger to ensure that the assembled unit is the same as the tested assembly. For the purposes of NAFS-08, the prehanger (assembler of door, glass, jamb, sill, hinges, etc) is considered the manufacturer of the prehung unit. All references to manufacturer in NAFS-08 refer to the prehanger. Product performance claims and labeling are the responsibility of the prehanger.

Q:  What level of performance is a “pass”?

A:  For single family detached homes, the building code requires Performance Grade ‘R’ for Air, Water and Structural performance, with the exception of one main entry door with overhang per dwelling, which is allowed to comply with a reduced Water Infiltration requirement (LW = Limited Water is allowed).

Q:  Is a “pass” sufficient for all applications?

A:  Performance grade requirements may be higher for doors with more exposure (less protection) than others on the same house, or homes in open unprotected terrain. The Canadian Supplement to the NAFS-08 standard also suggests choosing higher performance levels for locales with high wind (storm) activity.

Q:  Who is responsible for selecting the right Performance Grade for each different door in each different part of the house?

A:  The installer, builder, or architect/designer is responsible for selecting and specifying the appropriate Performance Grade for each exterior prehung door.

Q:  How will building inspectors know which Performance Grade a prehung door meets?

A:  Labels describing the Performance Grade test results for air and water, etc, must be applied by the prehanger. Upon request, the prehanger must supply test data for the assembly.

Q:  If we’ve tested a prehung, but wish to change a sill, door, or other component that we know to be ‘better’ is the test still valid?

A:  Test results are only considered valid for the components and assembly tested. Alternatively, prehangers may choose to participate in a Certification program, which may allow evaluation of proposed new components, and substitution based on previous test results.

Q:  A component supplier tells me their component ‘passes B-3’. Do I still need to test my prehung assembly?

A: Components such as door slabs or glass lite kits cannot be tested alone for air infiltration or water penetration. NAFS-08 test reports apply only to the complete prehung assembly.

Q:  Where can I see the text of the 2011 BC Building Code?

A:  The 2011 BCBC is not available yet. However it is known that it will reference the NAFS-08 specification.

Q:  Where can I get a complete copy of the NAFS-08 standard and the Canadian Supplement?

A:  The North American Fenestration Standard of 2008 (NAFS-08), more properly known as AAMA/WDMA/CSA 101/I.S.2/A440(2008), is available for sale at http://www.shopcsa.ca/onlinestore/GetCatalogItemDetails.asp?mat=2019692

The Canadian Supplement to NAFS, A440S1-09, is available at http://www.shopcsa.ca/onlinestore/GetCatalogItemDetails.asp?mat=2020631&product=A440S1-09&source=ProductDetailCrossSell.