Fire Requirements For Foam Plastic Insulation and WRBs in Exterior Walls

Presented to By Jesse J. Beitel July 31, 2012

Learning Objectives

 Code requirements for foam plastic in exterior walls  History of NFPA 285 Fire test  Other Fire tests required  Code requirements for Water-Resistive Barriers  Applicability and Use of NFPA 285

Continuous Insulation (CI) Concept

   ASHRE 90.1 – Commercial IECC (Energy Code) – Commercial & Residential Concept – Wrap building w/ insulation outboard of studs  Helps with thermal conduction, dew point, etc.

 Creates high R-value walls 3

Insulation In Exterior Walls

   Location in walls – CI / Cavity / Both Can use noncombustible or combustible non-foam plastic insulation  Fiberglass, Mineral wool   Cellulose, others Minimal fire requirements Can use combustible foam plastic insulation  Many types – XPS, EPS, Polyiso, SPF, etc.

 Characteristics different  Regulated the same  Fire requirements for walls and foam plastics vary based on Type of Construction, etc.

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Fire Requirements Vary

 One & Two Family Dwellings – Exterior walls - IRC regulates  Type V – Exterior walls - combustible – IBC regulates  Types I, II, III, IV – Exterior walls to be noncombustible unless allowed – IBC regulates 5

IRC (2012) Fire Requirements

 Non-foam plastic insulation  Noncombustible or if combustible then FSI ≤25 & SDI ≤450  Foam plastic insulation  Labeled  FSI ≤75 & SDI ≤450  Protected by 15-minute Thermal Barrier  Gable ends in attics – Protect with ignition barrier  Fire Resistance of exterior walls 6

IBC (2012) – Type V Fire Requirements

   Non-foam plastic insulation  Noncombustible or if combustible then FSI ≤25 & SDI ≤450 Foam plastic insulation (Chapter 26)   Labeled FSI ≤75 & SDI ≤450   Protected by 15-minute Thermal Barrier Gable ends in attics – Protect with ignition barrier Fire Resistance of exterior walls 7

IBC (2012) - Fire Requirements For Type I, II, III or IV – Part 1

 Noncombustible Insulation - OK  Fiberglass  Mineral wool  Non-foam plastic combustible insulation   Cellulose Insulation, etc.

FSI ≤25 & SDI ≤450  Fire Resistance of exterior walls 8

IBC - Fire Requirements For Type I, II, III or IV – Part 2

 Foam Plastic Insulation  Regulated by §2603.5

 Applies to exterior walls of Type I – IV construction  Applies to buildings of any height  Exceptions: • • Type V buildings Cold Storage – 1 story & meets other reqm’ts 9

IBC - Fire Requirements For Type I, II, III or IV – Foam Plastic

      Meet the requirements of NFPA 285 For each combustible component SDI ≤450 (ASTM E84) FSI ≤25 & Maintain fire resistance rating (ASTM E119) Foam separated from interior of building by a Thermal Barrier  Gable ends in attics – Protect with ignition barrier Limits on amount of foam (btu/ft 2 ) (mJ/m 2 ) No ignition when tested via NFPA 268 (Radiant heat exposure test) 10

History - Fire Test/Code Development

 In mid 1970’s – use of foam plastic on or in noncombustible exterior walls was proposed.

 EIFS & Steel/Foam/Steel Panels  Problems with use:  Exterior walls of Type I, II, III or IV Construction must be noncombustible construction.

 Foam plastic is combustible  Issues raised over potential for vertical and horizontal fire spread due to the combustible foam plastic insulation 11

History (continued)

 SPI began work in Codes and testing.

 Discussions w/ Code & Fire Officials.

 Drafting of Code language.

 Testing program  Testing was to determine efficacy of proposed wall systems to resist flame spread.

Multi-Story Fire Test

 Can the wall covering, insulation & assembly resist:  Flame propagation over face of the wall covering  Vertical flame propagation within the combustible core or components  Flame propagation over interior surface from one floor to the next  Lateral Flame propagation to adjacent compartments  Does not address floor-line joint per se.

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UBC 17-6 / UBC 26-4 Test In Progress 14

Fire Test/Code Development

     Test program completed in late 1980 Code change to Plastics Section adopted in 1988 UBC Versions adopted by NBC and SBC Full-scale test was also adopted as UBC 17-6. Used by all ESs.

In 1994 edition of UBC – reorganization moved plastics to Chapter 26 and test method became UBC 26-4.

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Fire Test/Code Development (Cont’d)

      In early 1990’s a “reduced-scale” fire test was developed.

New test adopted as UBC 26-9 in 1997 edition.

Test submitted to NFPA Committee on Fire Tests and it was adopted as NFPA 285 in 1998.

NFPA 285 “Standard Fire Test Method for Evaluation of Fire Propagation Characteristics of Exterior Non load-bearing Wall Assemblies Containing Combustible Components” ICC IBC specifies NFPA 285 Code requirements basically the same since 1988 UBC 16

NFPA 285 Test In Progress 17

IBC - Fire Requirements For Type I, II, III or IV – Foam Plastic

      Meet the requirements of NFPA 285 For each combustible component SDI ≤450 (ASTM E84) FSI ≤25 & Maintain fire resistance rating (ASTM E119) Foam separated from interior of building by a Thermal Barrier  Gable ends in attics – Protect with ignition barrier Limits on amount of foam (Btu/ft 2 ) (MJ/m 2 ) No ignition when tested via NFPA 268 (Radiant heat exposure test) 18

ASTM E84 Test Apparatus 19

ASTM E119 Wall after fire test 20

Thermal Barrier Requirement

 Code requires that foam plastic must be separated from the interior of the building by a 15-minute thermal barrier.

 Applies to any foam plastic application.

 Thermal barrier is typically 0.5 in. (12.7 mm) thick gypsum wallboard or meets NFPA 275.

 Thermal barrier retards heat transmission to the foam and delays its ignition.

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Ignition Barrier Requirement

     Applies to foam plastic insulation in attics & crawl spaces Only where entrance is made to service utilities Prescriptive ignition barriers provided in Code: wood, mineral fiber, gypsum wallboard or steel Not a thermal barrier Alternative assemblies by special testing 22

NFPA 259 Potential Heat Test

     Code requires that the “potential heat” (calculated on areal basis) of the foam plastic not exceed that which is tested via NFPA 285 Uses NFPA 259 – Measures amount of heat released when burned in pure O 2 Data from test expressed in Btu/lb (MJ/kg) Convert this to Btu/ft 2 (MJ/m 2 ) using thickness and density of foam plastic.

Allows calculation for different densities/thickness combinations 23

NFPA 268 Test

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WRB Definitions

 My definition = Weather-resistive barriers include:  Air barriers  Vapor barriers  Water barriers  ???? Barriers  IBC:  Water-resistive barrier

WRB Code Requirement 2012 IBC

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 combustible water-resistive barrier shall be tested in accordance with and comply with the acceptance criteria of NFPA 285.

Steel stud Interior wall membrane Foam insulation Exterior veneer WRB Sheathing Potential Variations of Wall Systems Insulation in stud cavity

How Do WRBs Meet NFPA 285?

 There is no one test or test assembly to qualify a WRB for use in all assemblies  Perform NFPA 285 test – WRB is one of several materials in assembly  Limited engineering analysis based on NFPA 285 tests in conjunction w/ small scale tests.

Engineering Analysis

 Use WRB X in a successful NFPA 285 test  Develop fire performance parameters for WRB X (ASTM E1354 Cone Calorimeter)   Develop fire performance parameters for WRB Y Compare fire performance parameters – if same or better, then maybe substitute Y for X in tested assembly

Applicability of NFPA 285

 285 is a test of a complete wall assembly  285 test results apply only to the tested construction – similar to ASTM E119  Substitutions of one material for another can cause different test results  Addition of combustibles (insulation, WRBs, etc.) can cause different test results 30

Applicability of NFPA 285 (Continued)

   Changes in configurations (air gaps, attachment systems, etc.) can cause different results Wall systems made of a number of previously NFPA 285 tested materials does not ensure a successful NFPA 285 test Tests are required for many various veneers and other combustible wall components – insulation, WRBs 31

Applicability of NFPA 285 WRBs

 Use of WRBs can cause different results  Substitution of WRBs can cause different results  Even tested WRBs cannot necessarily be applied to other foams, veneers, etc.

 Same issues as with other NFPA 285 tests – materials, configuration., etc.

Summary

 Insulation in exterior walls is regulated.

 Amount of regulation / tests for exterior insulation and/or insulated exterior walls depends on:  Code  Type of Construction  Type of insulation  WRBs 33

Summary - Continued

 NFPA 285 provides a determination of vertical fire performance of exterior wall assemblies.

 NFPA 285 tested systems reduce the potential for vertical flame spread by exterior walls.

 NFPA 285 data/results must be used in an appropriate manner. 34

Thank You and Questions?

Jesse J. Beitel Senior Scientist/Principal Hughes Associates, Inc.

410/737-8677 [email protected]