During the 2012 Code Change Cycle, several changes were proposed to the sections in the 2012 IBC that require the use of NFPA 285 testing on exterior walls. NIBS and AIA collaborated on two and a third was proposed by DuPont. The DuPont change was recommended by the hearing committee for As Submitted, but with the understanding that it was a compromise solution between those that didn't want any change and those that wanted to delete the reference totally.
This past summer NIBS hosted meetings of various interests in this issue to help focus the discussion. Although total agreement couldn't be reached, there was a consensus regarding the problem and several solutions were offered to the ICC membership for consideration in October at the annual meeting.
The final decision by the membership was to accept two modifications to revise Section 1403.5 and adding the following three exceptions:
1403.5 Vertical and lateral flame propagation. Exterior walls on buildings of Type I, II, III or IV construction that are greater than 40 feet (12 192 mm) in height above grade plane and contain a combustible water-resistive barrier shall be tested in accordance with and comply with the acceptance criteria of NFPA 285. For the purposes of this section, fenestration products and flashing of fenestration products shall not be considered part of the water resistive barrier.
Exceptions:
1. Walls in which the water-resistive barrier is the only combustible component and the exterior wall has a wall covering of brick, concrete, stone, terra cotta, stucco or steel with minimum thicknesses in accordance with Table 1405.2.
2. Walls in which the water-resistive barrier is the only combustible component and the water-resistive barrier has a Peak Heat Release Rate of less than 150 kW/m2, a Total Heat Release of less than 20 MJ/m2 and an Effective Heat of Combustion of less than 18 MJ/kg as determined in accordance with ASTM E1354 and has a flame spread index of 25 or less and a smoke-developed index of 450 or less as determined in accordance with ASTM E84 or UL 723. The ASTM E1354 test shall be conducted on specimens at the thickness intended for use, in the horizontal orientation and at an incident radiant heat flux of 50 kW/m2.
3. Windows and doors and flashing for windows and doors shall not be considered to be part of a water resistive barrier for purposes of this section.
A definition that is found in the IECC for fenestration was also added to the IBC.
FENESTRATION. Skylights, roof windows, vertical windows (fixed or moveable), opaque doors, glazed doors, glazed block and combination opaque/glazed doors. Fenestration includes products with glass and nonglass glazing materials.
These will appear in the 2015 edition of the IBC. These changes may also be instructive to those that are struggling with approvals under the currently adopted codes.
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David Collins FAIA
President
Preview Group, Inc.
Cincinnati OH
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Original Message:
Sent: 11-09-2012 11:18
From: Geoffrey Walters
Subject: NFPA 285
The Chapter 26 code language requiring compliance with NFPA 285 is as follows:
"2603.5 Exterior walls of buildings of any height. Exterior walls of buildings of Type I, II, III or IV construction of any height shall comply with Sections.............."
.....therefore in my reading it is not limited to non load bearing curtainwall assemblies. When product reps say their products meet NFPA 285 what it should mean is that they have an ICC Evaluation Report showing the results of their product's inclusion in a successful 285 test and precisely delineating the assembly's composition as tested.
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Geoffrey Walters AIA
Chicago IL
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