Building Performance Knowledge Community

I read some interesting articles about NFPA 285 in the JBED Summer 2012 magazine.  There seems to be a lot of confusion about this standard.  It seems that some product reps are still saying their products meet NFPA 285, but isn't that misleading?  My understaning is that the test is for assemblies and not components.  I am seeking feedback on applying this standard to design.  Should we make sure owners have enough testing money in their budget since no two wall assemblies are the same?  Should all components be noncombustible to avoid testing?  Are their any published tests with SPF insulation?  What do us architects need to know about 285?

Thank you,

-------------------------------------------
John Gresko AIA
-------------------------------------------

I've also heard product reps say their products meet NFPA 285.  The test is for non-load-bearing curtainwall assemblies, as I read it.  I've also been told by code officials that it was applicable to bearing walls in their opinion.  While code officials arguably have the right to interpret and apply requirements, vendors should not be doing the same.          

-------------------------------------------
Drake A. Wauters, AIA
TDBP Advisory Group
Senior Technical Architect
Arlington, Virginia
-------------------------------------------

John,
We've been trying to comply with NFPA 285 on a state office building project. Our reviewing authority was not aware of all of the requirements. In addition, our state requires the LEED definition of 9% recovered post industrial recycled content in XPS foam.

Allowing money in the project for testing seems prohibitively expensive for an individual client.
Using only non-combustible products depends on what you feel about formaldehyde in mineral wool and using polyiso in below grade wet conditions.  We used a combination of Polyiso and XPS with mineral wool fire stopping at the window heads. 

BASF -Walltight SPF claims to meet 285, however they do not sell their XPS product in the USA.
DOW XPS does not meet the definition for LEED 9% recovered recycled content.

Several times we were referred to the Hughes report summarizing tests sponsored by the XPSA that implies that various configurations will meet 285 based on a table that includes extruded polystyrene Foam Insulation (XPS) - Type IV per ASTM C578.

Frank
-------------------------------------------
Frank Marshall AIA
Architect
SMB&R Inc
Camp Hill PA
-------------------------------------------

John,
In my opinion the following is critical information about NFPA 285 (it is a good start and is not an exhaustive list):

1. Architects, Owners and related design/development professionals must be aware of this requirement as it will increasingly impact projects as new codes are adopted and move to improve our energy performance.

2. The increasing requirements of energy codes, incentive programs, and third-party certifications have pushed the industry to more thermally resistive assemblies, typically including continuous exterior insulation. This has typically been in the form of foam plastics due to its relatively higher R-Value.

3. Triggers to require the NFPA 285 test method has been incorporated in chapter 26 of the IBC since its original publication in 2000 (and in some legacy codes prior) which is typically triggered when foam plastics and other "combustible" materials are incorporated into "non-combustible" wall assemblies (Type I, II, III, or IV). Type V construction does not require NFPA 285 in most circumstances.

4. NFPA 285 is an assembly test (period). A material in isolation cannot be "NFPA 285 compliant". A compliant ASSEMBLY requires a full description of each layer of the assembly (similar to UL descriptions of fire rated assemblies), including descriptions of proprietary materials/sub-assemblies and penetrating details such as windows, flashings, etc. Compliance with NFPA 285 may be shown by project specific testing ($15-50K per test depending on the assembly); use of a previously tested compliant assembly; or a letter of Engineering Judgement indicating that the proposed assembly would perform at least as well as a previously tested similar assembly.

5. Until the adoption of the 2012 IBC, "Non-combustible" continuous insulation, such as mineral wool, is one path to avoid the NFPA 285 requirements in 2603.

6. In the 2012 IBC per § 1403.5, the use of combustible WRB's in non-combustible assemblies was added as a separate trigger for NFPA 285 along with several other new triggers. Most (if not all) WRB's are "combustible"; therefor, "non-combustible" wall assemblies with a WRB will require NFPA 285 compliance under the 2012 IBC (unamended).

7. Unsuccessful efforts by AIA, NIBS and others were made at the ICC code hearings for the 2015 IBC to clarify and insert reason into the NFPA 285 requirements. One proposal did gain traction (FS 147) to set exceptions to 1403.5 based on the heat released from a WRB product, the use of "heavy cladding" (e.g. brick), and for fenestration flashing. It is currently unclear to me what products would meet the heat released exemption; however, one could assume based on the values that this would be limited to lightweight mechanically attached sheet goods and likely new untested by time materials in this application...

In summary, compliance with NFPA 285 as currently written in the 2000 through 2015 IBC will be incorporated into more of our projects as we strive for increased thermal resistivity of our walls. We need to understand these requirements and there impacts. Further, I would challenge those who are concerned to get involved with you local AHJ to educate there leaders and influence the adoption, modification, and enforcement of these requirements to address the specific needs and concerns of your community.

Regards,

Keith

-------------------------------------------
Keith Nelson AIA
Senior Associate / BEC'DC Co-Chair
Wiss, Janney, Elstner Associates, Inc.
Fairfax VA
-------------------------------------------

A classic example of the code pulling architects in 2 different directions; energy code requires continuous insulation, and building code prevents use of certain higher performing insulations (XPS) due to flammability.  One also wonders if this is yet another industry lobbying for the benefit of their products.  How did these flammable products exist in buildings for 30 years without catastrophic building fires every day?

 Keith Nelson's summary is excellent.  I believe the requirement for NFPA 285 assembly test came from the UBC.  The big problem is it is an assembly test thus each assembly must be tested.   Many manufacturers have published which assemblies they have tested their products with (or received engineering analysis equivalency) and what the maximum insulation thickness is, as well as special details for the window head and jamb.  Both Dow Styrofoam and Owens Foamular have these on their web sites, or can be obtained from their reps.    Try google and the manufacturer's name and NFPA 285.

Hughes Associates has worked with many manufacturers.

Now that you've see the light regarding the requirements for NFPA 285, look to see which air barrier manufacturers meet ASTM E84 and Class A.  According to ICC staff air barriers must meet Class A flame spread under Section 720.1 (IBC 2012)  

"Insulating materials, including facings such as vapor retarders and vapor-permeable membranes, similar coverings and all layers of single and multilayer reflective foil insulations, shall comply with the requirements of this section."

 

I sought a formal ICC interpretation and was denied because the code is clear  - Air barriers are "similar coverings" and must meet Class A flame spread under Section 720.1.  Very few have the testing.

 -------------------------------------------
Paul Stockert AIA
Technical Director
EYP Architecture & Engineering P.C.
Albany NY
-------------------------------------------

John,
Owens Corning just released a free NFPA 285 training course today on their website www.OCBuildingSpec.com
You have to register and search "285".   The course describes three fires in relatively new buildings in Bejing, Korea and Las Vegas that are believed to have been spread by unprotected exterior foam.
Frank

-------------------------------------------
Frank Marshall AIA
Architect
SMB&R Inc
Camp Hill PA
-------------------------------------------