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NFPA 285 Testing for Exterior WallsRequirements and Design Challenges

Brian D. Kuhn, Jr., P.E.

28 November 2011

Simpson Gumpertz & Heger Inc. is a Registered Provider with TheAmerican Institute of Architects Continuing Education Systems (AIA/CES).Credit(s) earned on completion of this program will be reported toAIA/CES for AIA members. Certificates of Completion for both AIAmembers and non-AIA members are available upon request.

This program is registered with AIA/CES for continuing professionaleducation. As such, it does not include content that may be deemedor construed to be an approval or endorsement by the AIA of anymaterial of construction or any method or manner of handling, using,distributing, or dealing in any material or product.

Questions related to specific materials, methods, and services will beaddressed at the conclusion of this presentation.

28 November 2011 NFPA 285 Testing for Exterior Walls 2

Copyright Materials

This presentation is protected by US andInternational Copyright laws. Reproduction,

distribution, display and use of the presentationwithout written permission of the speaker is

prohibited.

© Simpson Gumpertz & Heger Inc. 2011


The presentation addresses fire testing requirements for combustible

exterior wall materials as found in the International Building

Code. There is currently a lack of consistent interpretation and

enforcement of such requirements among designers and code

enforcement bodies. This presentation will summarize the language of

the building code as it relates to fire test requirements for exterior walls,

the nature of the referenced test standards, and the application of

tested assemblies in typical wall design.

Course Description


Learning Objectives

• Identify exterior wall materials and systems that requirefire propagation testing.

• Distinguish between the NFPA 285 test and alternatetest methods.

• Interpret product literature and reports of tested wallcomponents and assemblies.

• Incorporate compliant materials and systems intoexterior wall design.


• Structural Engineering

• Building Science &Technology

• Materials Science

• Fire Safety Engineering

• Laboratory


Simpson Gumpertz & Heger

BARRIER 1:Waterproofing

BARRIER 2:Insulation

BARRIER 3:Vapor Retarder

BARRIER 4:Air Barrier

Rainwater/GroundwaterControl

CondensationControl&Energy Consumption

BUILDING SCIENCE


Exterior Wall Fundamentals


Exterior Wall Fundamentals

Presentation Overview

• How the Code Reads– Requirements for Combustible Materials in Walls

– The NFPA 285 Test Standard

– Special Approval language

• What’s Happening in Practice– Design Challenges in Working with NFPA 285

– Issues with Currently Approved Assemblies

– A Look at the NIBS RFP

• Where We Need to Go

**All code references in accordance with 2009 IBC. Codes vary by jurisdiction;requirements for individual projects should always be verified on a case-by-case basis.**


• A building shall be classified as one of five types ofconstruction (IBC Chapter 6)

Code Requirements


Code Requirements

• Combustible materials


Code Requirements

Combustible materials are permitted in non-combustibleconstruction (Section 603):

• Combustible exterior wall coverings in accordance withChapter 14– Exterior Insulation and Finish Systems (EIFS)

– Metal Composite Materials (MCM)

– High-Pressure Laminates (HPL) (2012 IBC)

• Plastics in accordance with Chapter 26– Fiber Reinforced Polymers

– Foam Plastic Insulation

• Exterior plastic veneer in accordance with Section2605.2


Code Requirements

• Side note on plastic veneer (think: vinyl siding)– Not subject to NFPA 285 testing

– Can’t be used higher than 50 feet above grade

– Has requirements for self-ignition temperature, smoke-developedindex, and combustibility classification

• Side note on water-resistive barriers (2012 IBC)– NFPA 285 testing will be required for all exterior wall systems

greater than 40 feet in height that include a combustible water-resistive barrier


Code Requirements

Metal Composite Materials (Section 1407)

• Definitions:– MCM: Factory-manufactured panel consisting of metal skins

bonded to both faces of a plastic core (foam plastic exempted)

– MCM System: Exterior wall covering fabricated using MCM in aspecific assembly including joints, seams, attachments, substrate,framing, and other details as appropriate to a particular design


Alpolic PE

Code Requirements


• Fire safety requirements:– Fire-resistance rating of wall maintained (ASTM E 119)

– Surface-burning characteristics (Class B) (ASTM E 84)

– Full-scale NFPA 285 testing, or comply with alternateconditions


Alpolic PE

Code Requirements


• Option 1: Unlimited height– NFPA 285 testing and Class A rating

• Option 2: Installations up to 40 feet– Unlimited surface coverage, unless fire separation distance

less than 5 feet (10% coverage limit)

• Option 3: Installations up to 50 feet– Self-ignition temperature of 650F or greater

– Sections of MCM shall not exceed 300 sf, and shall beseparated at least 4 feet vertically


Code Requirements

Metal Composite Materials (Section 1407) (2012 IBC)

• Option 4: Installations up to 75 feet– Self-ignition temperature of 650F or greater

– Area limitations

– Prohibited occupancies (A-1, A-2, H, I-2, I-3)

– Limited to non fire-resistance rated walls

– Exceptions for automatic sprinkler systems

• Option 4a: Installations up to 75 feet– Self-ignition temperature of 650F or greater

– Area limitations

– Fire separation distance must be greater than 30 ft

– Exceptions for automatic sprinkler systems


Code Requirements


• Full Scale Tests. The MCM system shall be tested inaccordance with, and comply with, the acceptancecriteria of NFPA 285. Such testing shall be performedon the MCM system with the MCM in the maximumthickness intended for use.

• MCM System: Exterior wall covering fabricated usingMCM in a specific assembly including joints, seams,attachments, substrate, framing, and other details asappropriate to a particular design


Code Requirements

Plastics (Chapter 26)

• Fiber Reinforced Polymers (FRP)

• Foam Plastic Insulation (FPI)– Exterior Finish and Insulation Systems (EIFS)

• Expanded polystyrene (EPS)

– Rigid insulation

• Polystyrene (XPS)

• Polyisocyanurate (ISO)

– Spray polyurethane (SPUF)


Code Requirements

Fiber Reinforced Polymers (Section 2612)

• Option 1a: Unlimited height– NFPA 285 testing

• Option 1b: Unlimited height– Class A rating – up to 20% coverage

– Class B rating – up to 10% coverage

– Applied to, or separated by, a noncombustible substrate

• Option 2: Installations up to 40 feet– Unlimited surface coverage, unless fire separation distance less

than 5 feet (10% coverage limit)

– Class C rating

NOTE: All options require fireblocking


Code Requirements

Section 2603.5. Exterior walls of Types I, II, III, IVconstruction greater than one story*.

1. FPI can’t decrease the fire-resistance rating

2. Thermal barrier must separate FPI from building interior

3. Limited potential heat of FPI

4. Class A rating

5. The wall assembly shall be tested in accordance withand comply with the acceptance criteria of NFPA 285

6. Proper labeling required

7. Must past ignition resistance test


Code Requirements

Section 2603.9 Special approval

• FPI is not required to comply with 2603.4 through 2603.7where approved based on large-scale tests– NFPA 286 and UL 1715: Standard Room Corner Tests

– FM 4880 and UL 1040: Large-scale Room Corner Tests

• “Such testing shall be related to the actual end-useconfiguration…assemblies tested shall include seams,joints and other typical details used in the installation ofthe assembly…”


• Original full-scale version was first codified in 1988Uniform Building Code (UBC) as Test Standard 17-6

• Society of Plastics Industry (SPI) testing in early 1990sled to the intermediate-scale UBC 26-9 in 1997 UBC

• NFPA adopted NFPA 285 in 1998 based on UBC 26-9

• Each IBC edition has referenced NFPA 285

The NFPA 285 Test


• Application. Standard used to evaluate firepropagation characteristics of wall assemblies, asfollows:

– Vertical flame propagation:

• over the exterior face of the wall assembly

• within the combustible core or within combustiblecomponents from one story to the next

• over the interior surface of the wall assembly from onestory to the next.

– Lateral flame propagation from the compartment offire origin to adjacent compartments or spaces.

The NFPA 285 Test


The NFPA 285 Test


The NFPA 285 Test


The NFPA 285 Test


The NFPA 285 Test

• Testing Laboratories– Intertek (San Antonio, TX)

– Southwest Research (San Antonio, TX)

– Architectural Testing (York, PA) (coming Spring 2012)

• Cost– $15,000 to $20,000

• Timeframe– 6 to 10 weeks


Special Approval

Section 2603.9 Special approval

• FPI is not required to comply with 2603.4 through 2603.7where approved based on large-scale tests– NFPA 286 and UL 1715: Standard Room Corner Tests

– FM 4880 and UL 1040: Large-scale Room Corner Tests

• “Such testing shall be related to the actual end-useconfiguration…assemblies tested shall include seams,joints and other typical details used in the installation ofthe assembly…”


Special Approval

• NFPA 286, UL 1715: Standard room corner test

• Pass/fail based on flame spread, heat released, smokegenerated, flashover


Special Approval

• FM 4880 –Large-scaleroom corner test


Photograph courtesy ofFM Approvals

Special ApprovalPhotograph courtesy of

FM Approvals


Special ApprovalPhotograph courtesy of

FM Approvals


Special Approval

Section 2603.10.1 Exterior Walls (2012 IBC)

• Testing based on Section 2603.10 shall not be used toeliminate any component of the construction of anexterior wall assembly when that component wasincluded in the construction that has met therequirements of Section 2603.5.5.


Design Challenges

#1 Special approval section is unclear (2012 IBC languagedoesn’t help)

#2 Lack of a central directory of NFPA 285-approvedassemblies

#3 Unclear path for modifying tested assemblies

#4 Typical wall designs include components or details thatare not consistent with tested assemblies


Design Challenges

Challenge #1

• Special approval section is unclear

• Why is the requirement for exterior wall fire testingwaived by an interior finish test?

• Various interpretations on the subject


Design Challenges

Challenge #2

• Lack of a central directory

• For other fire-resistive assemblies, the industry referenceis Underwriters Laboratories’ Fire Resistance Directory

• For assemblies tested to NFPA 285, there is no suchcompilation of approved assemblies


Design Challenges

• Foam Sheathing Coalition memo – 26 Oct 2010


Design Challenges

• International Code Council (ICC) Engineering Service(ES) reports are not always clear

• Two examples:– Standard EIFS by Parex

– STYROFOAM rigid insulation by Dow


Design Challenges


Design Challenges


Design Challenges


Design Challenges


Design Challenges

• To gain understanding of all details of the testedassembly, the designer needs to correspond with thesponsor of the test.

• For an assembly test with multiple components andmanufacturers, who sponsors the test?

• So far, it has been the insulation manufacturers


Design Challenges


Design Challenges


Design Challenges


Design Challenges

Challenge #3

• Mechanism for substitution of components– Size of air space

– Type of water-resistive barrier

– Other details

• ES Acceptance Criteria (AC) 12 allows for extension oftest data through engineering analysis

• Equivalency required for project?


Design Challenges

Challenge #4

• Common wall designs include components or details thatare not consistent with tested assemblies– Lack of approved asphalt-based membranes in field of wall


Design Challenges

Challenge #4

• Common wall designs include components or details thatare not consistent with tested assemblies– Lack of approved asphalt-based membranes in field of wall

• Will be further complicated by 2012 IBC language– NFPA 285 testing required for all exterior wall systems greater

than 40 feet in height that include a combustible water-resistivebarrier


Design Challenges

Challenge #4

• Common wall designs include components or details thatare not consistent with tested assemblies– Required fire safing at window openings


• Aesthetic concerns

• Water collection anddrainage concerns

• Thermal bridge

• Flashing??

Detail from Dow literature


Design Challenges

Continuous Steel Lintel/Shelf Angle on Steel Framing

Design ChallengesDetail fromOwens Corningliterature


Design Challenges

Challenge #4

• Common wall designs include components or details thatare not consistent with tested assemblies– MCM Systems have not passed NFPA 285 with XPS insulation


• Common systems maynot meet letter of thecode

Where Do We Go From Here?



• National Institute of Building Sciences (NIBS) –Request for Proposal to evaluate IBC requirements andNFPA 285 test standard




• Use existing NFPA 285 testedsystem, possibly modifiedwith engineering judgment

• Jurisdiction-specific solutions

• Test new system

• Switch to a non-combustibleinsulation (mineral wool)

Design Alternatives


Mineral wool insulation

• Lower R-value than XPS– Larger cavity space

– Wider horizontal relievingangles

• Thermal performance whenwet

• Track record?

• Recycled content can beused toward LEED credits

• Still use asphalt-basedWRBs



Weather-resistive barriers

• Manufacturers aredeveloping impermeableself-adhered membranesfor compliance with NFPA285



NFPA 285 Directory

• Underwriters Laboratories?

• NFPA?

• Foam Plastics Industry?



Communication with Stakeholders

• Design Team

• Owner

• Authority Having Jurisdiction(AHJ)



www.sgh.com

Thank You

Brian D. Kuhn, Jr., P.E.

[email protected]

(781) 907-9328

nfpa 285 testing for exterior walls - bec boston.ppt 285 testing for exterior walls requirements and...

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