Can it pass the NFPA 285 test per Sec...

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Author Message J. Peter Jordan (Unregistered Guest) Unregistered guest Posted on Friday, February 18, 2011 - 12:21 pm:    This issue was raised in another thread, but I have recently had it come on in a different kind of assembly. Exterior Wall Assembly (outside to inside): Metal wall panel, rigid polyurethane insulation; gypsum sheathing, steel studs with glass fiber batts, gypsum board. The height of this assembly is one story on the second floor of a unversity building. I suspect that this test was originally directed at EIFS assemblies, but the way the code reads, it applies to any assembly that contains "plastic insulation." As we move to wall assemblies that include a plane of continuous insulation (usually plastic board insulation), this requirement will begin to kick in for all types assemblies. Is anyone testing this stuff? Dale Hurttgam, NCARB, AIA,LEED AP, CSI Senior Member Username: dwhurttgam Post Number: 78 Registered: 10-2005 Posted on Friday, February 18, 2011 - 05:52 pm:    I have been hearing alot of discussion regarding NFPA 285. Dow and Centria have systems that have been tested to this standard, and I believe many other manufacturers have tested systems also. One of the key things that has been noted is that NFPA 285 is an "assembly test" so you need to use specific components that have been tested as an "assembly" - no substituting of "similar construction". One resource that I was recently referred to is an August 2010 article re: NFPA 285 that appeared in the ICC Journal: http://bsj.iccsafe.org/august/august_PDFs/augbsj_codeandfire_test.pdf Sheldon Wolfe Senior Member Username: sheldon_wolfe Post Number: 464 Registered: 01-2003 Posted on Sunday, February 20, 2011 - 12:52 pm:    Consider mineral wool instead of foam insulation. J. Peter Jordan (Unregistered Guest) Unregistered guest Posted on Monday, February 21, 2011 - 10:58 am:    Does mineral wool come in a rigid form with R-values comparable to polyurethane? Dave Metzger Senior Member Username: davemetzger Post Number: 388 Registered: 07-2001 Posted on Monday, February 21, 2011 - 11:27 am:    Mineral wool is available in densities of 4 pcf and 8 pcf. For use in cavities it should be treated to be hydrophobic, ie to shed water. Roxul makes a product called Cavity Rock for this purpose. If some one knows of comparable products by other manufacturers I'd be grateful to know of them. Mineral wool has a lower k-value than does polyurethane and than extruded polystyrene. ken hercenberg Senior Member Username: khercenberg Post Number: 78 Registered: 12-2006 Posted on Tuesday, February 22, 2011 - 05:21 pm:    Hi Dave. Thermafiber claims that their RainBarrier product is suitable for use in cavities. See http://www.thermafiber.com/?Page=RainBarrier&id=66&p=1 for more information. Brian E. Trimble, CDT Senior Member Username: brian_e_trimble_cdt Post Number: 39 Registered: 08-2005 Posted on Wednesday, February 23, 2011 - 08:37 pm:    One thing that I would like to know is where did this requirement come from (possibly EIFS) and why is it applied to all wall systems? Dale, the article from Building Safety Journal was very informative. It mentions that even brick veneer wall systems should be tested. Really?!? A 4 inch brick veneer gives a one hour fire rating by itself meaning that the temperature stays less than 250 deg. on the non-fire side, not enough to ignite polystyrene insulation. This leads me to my other question, is this a way for testing companies to make more money on selling tests - "...if you change wall components or add new combustible materials, additional NFPA 285 testing may be required to verify that the wall assembly meets Code." Sorry if I sound insolent.... Ronald L. Geren, AIA, CSI, CCS, CCCA, SCIP Senior Member Username: specman Post Number: 927 Registered: 03-2003 Posted on Thursday, February 24, 2011 - 12:07 am:    It is only required when foam plastic is incorporated into the exterior wall assembly. No foam plastic...no NFPA 285 test required. Ron Geren, AIA, CSI, CCS, CCCA, SCIP www.specsandcodes.com J. Peter Jordan (Unregistered Guest) Unregistered guest Posted on Thursday, February 24, 2011 - 11:09 am:    My point is that with the requirements for continuous insulation in the wall assembly (see my first post on the assembly description), more people will be trying to incorporate plastic insulation. The alternative for mineral fiber that several people have proposed may meet the intent, but rigid mineral fiber has an R-value 20 to 30 percent lower than the foam insulation. Ronald L. Geren, AIA, CSI, CCS, CCCA, SCIP Senior Member Username: specman Post Number: 928 Registered: 03-2003 Posted on Thursday, February 24, 2011 - 02:19 pm:    Peter, you're correct...that's the trade off: --Better thermal resistance, but comply with the test; or, --Lower thermal resistance, but no test required. With the exception of mass walls, the intent of continuous insulation is not necessarily the added R-value (which helps), but the elimination of the thermal bridging between the interior elements of the exterior wall and the exterior elements. Insulating materials that do not require the NFPA 285 test will also provide that thermal break. According the the International Energy Conservation Code, most continuous insulation requirements for walls in the majority of the continental U.S. (Climate Zone 6 and lower) can be achieved with non-foam plastic insulation in thicknesses of 4 inches or less (even for mass walls). Ron Geren, AIA, CSI, CCS, CCCA, SCIP www.specsandcodes.com Wayne Yancey Senior Member Username: wayne_yancey Post Number: 429 Registered: 01-2008 Posted on Thursday, February 24, 2011 - 04:09 pm:    The 2 most popular mineral wool exterior insulations in semi-rigid form are from Thermafiber and Roxul. Density varies from 4 - 8 pcf but R-value is 4.2/inch. XPS is 5/inch. FYI, Aside from the approval issues of using XPS for continuous insulation, the City of Seattle has tightened the requirements for the use of continuous insulation amoung other requirements that involve curtain wall. The use of continuous Z-girts is being re-evaluated for projects in Seattle. The rest of the state has not spoken up. An excerpt of the relevant text from Chapter 2 of the 2009 Washington State Energy Code is used as the basis of Seattle Code. Seattle additions to the WA state code start with sectence "For the purposes of this..." This has led to a search for innovative methods for attaching claddings such as composite metal wall panels. These requirements came into effect Jan 1/2011. There is a movement at the state capital to have them postponed. Companies such as Kawneer have been caught off guard on other provisions effecting their aluminum-framed products. CONTINUOUS INSULATION (c.i.): Insulation that is continuous across all structural members without thermal bridges other than fasteners (i.e. screws and nails) and service openings. It is installed on the interior or exterior or is integral to any opaque surface of the building envelope. For the purposes of this definition of continuous insulation, only screws and nails are considered fasteners. Insulation installed between metal studs, z-girts, z-channels, shelf angles, or insulation with penetrations by brick ties and offset brackets, or any other similar framing is not considered continuous insulation, regardless of whether the metal is continuous or occasionally discontinuous or has thermal break material. (See Section 1332 for determination of U-factors for assemblies that include metal other than screws and nails.) Like the trickle down effect of California laws, this requirement may find it way into other states in the temperate climate zones. J. Peter Jordan (Unregistered Guest) Unregistered guest Posted on Thursday, February 24, 2011 - 08:38 pm:    Soon they will want to stick this on with partially chewed structural bubble gum (non conductive). I am floored in this discussion that the people worried about the thermal bridging issues seem to have little awareness of the need to transfer wind loads from the exterior veneer to some sort of structure. John Regener, AIA, CCS, CCCA, CSI, SCIP Senior Member Username: john_regener Post Number: 509 Registered: 04-2002 Posted on Friday, February 25, 2011 - 10:25 am:    Peter: Wind loads are not part of the LEED AP exam and therefore are inconsequential unless the wind is sustainable and locally harvested. John Bunzick, CCS, CCCA, LEED AP Senior Member Username: bunzick Post Number: 1306 Registered: 03-2002 Posted on Tuesday, March 01, 2011 - 11:26 am:    Ron is correct that the Chapter 26 requirement for foam plastic insulation would not kick in if there was no foam in the cavity. However, Chapter 14 requires the NFPA 285 test when using metal composite materal (MCM) panels in certain conditions (over 30 feet, essentially). Since the NFPA 285 test is for a very specific assembly, that would mean unless the product is tested with mineral wool in the cavity, I don't believe you can't use it this way. There are very, very few tested assemblies with any insulation type at all in the cavity, and the MCM manufacturers don't really give a damn. They make only panels; it is the fabricators who turn them into curtain walls. Neither wants to test. Regarding brick veneer: I can confidently report that there are probably thousands of buildings like this in Massachusetts, and I'm guessing that virtually none have a tested assembly in them. I've no heard negative fire history for this condition. It is true that one code interpretation is that NFPA 285 is required for foam insulation in brick cavities. There is also an interpretation of the code that says other testing is acceptable, though that testing does not seem germaine to these assemblies. The various Building Enclosure Councils (BEC) across the contry are addressing this problem through BETEC, and plan to make a recommendation for an amendment to the code. Dale Hurttgam, NCARB, AIA,LEED AP, CSI Senior Member Username: dwhurttgam Post Number: 80 Registered: 10-2005 Posted on Tuesday, March 01, 2011 - 12:54 pm:    Surpisingly there are quite a few products that have been tested as exterior wall assemblies per NFPA 285 including brick cavity wall applications. I just went online and saw this item that identifies some of them: http://www.foamsheathing.org/images/TM_NFPA_285_Assemblies.pdf We had a project a number of years ago where the FM reviewer took issue with our brick veneer exterior wall with extruded polystyrene insulation board. It was such a standard of the industry that I was quite surprised that they would have a concern. The issue eventually went away and the project proceeded as designed. I was susequently told that the FM concern at the time had something to do with an isolated fire incident just prior to our project being reviewed.