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.

4
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
≤25 & SDI ≤450

or if combustible then FSI
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
≤25 & SDI ≤450

or if combustible then FSI
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 - FSI ≤25 &
SDI ≤450 (ASTM E84)
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/ft2) (mJ/m2)
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.
13
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.
15
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 Nonload-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 - FSI ≤25 &
SDI ≤450 (ASTM E84)
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/ft2) (MJ/m2)
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.
21
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 O2
Data from test expressed in Btu/lb (MJ/kg)
Convert this to Btu/ft2 (MJ/m2) using thickness and
density of foam plastic.
Allows calculation for different densities/thickness
combinations
23
NFPA 268 Test
24
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
Insulation in
stud cavity
WRB
Exterior
veneer
Cavity air space
Sheathing
Potential Variations of Wall Systems
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/ smallscale 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
jbeitel@haifire.com