| Author |
Message |
Marc C Chavez
Senior Member
Username: mchavez
Post Number: 426
Registered: 07-2002
| | Posted on Monday, December 12, 2011 - 03:01 pm: |    |
This forum has discussed NFPA 285 requirements for plastic insulation and an article from the ICC website clearly mentions that the assembly as a whole be tested - not something similar. see this link for the previously discussion http://discus.4specs.com/discus/messages/24/5477.html
Now a new wrinkle as sprung up. It appears that air barriers are considered a portion of the assembly as is the insulation, gypsum sheathing and in my case MCM panels.
HOW oh HOW are we building buildings without a constant stream of assemblies being trotted off to testing labs for the 30K NFPA 285 test for your PARTICULAR assembly?
This question came up last week on a job. The MCM manufacturer stated that they felt our vapor impermeable membrane would contribute to a failure in the system when tested and were anxious about its choice. They stated that they knew of several Vapor Permeable products on the other hand that would be OK.
I was at a loss. The NFPA 285 requirement has been in the IBC since 2000.
Why had this never come up before?
Have project architects been receiving these test results? They have been required in all of my specs since 2008(ish) (Thank you Speclink you have included this as standard language) Masterspec does NOT reference this test only ASTM E 84 and E 119
What is the difference, in a fire, between vapor permeable and impermeable?
How are air barriers or other products tested separately from the whole assembly?
Will the contractor/manufacturer have to test (at a cost of $30,000 each time) the MCM exterior wall assembly every time a different air barrier or insulation is selected?
There are 15 to 20 different MCM systems, tens of air barriers, hundreds of insulation brand names and products, resulting in thousands of possible combinations!
I got out NFPA 285 and read thru it. The test standard states in section 5.7 that
“The test specimen shall be constructed and secured …using fastening and construction details representative of actual field installation as specified by the manufacturer……joints or seams representative of standard construction practices…shall be incorporated”
I called NFPA and ask them what they thought. They agreed with me that testing every possible combination was never the intent of the standard but that the system does have to be tested.
The exterior assembly consists of the metal studs, the gypsum sheathing, the air barrier, any accessory tapes and sealants, the outboard insulation, the MCM framing system, the MCM panels. The sheathing, air barrier, and insulation are parts of the assembly (not joints and seals) that would logically need to be tested. The sheathing for our buildings is always “Type X” Gypsum sheathing has been part of these tests historically and should not be an issue.
Exterior insulation and the air barrier are two additional elements in the assembly that can affect test results.
I called my local Carlisle rep (their impermeable product is scheduled for the building at this time) He stated that he had just heard of this issue and the company had developed a new impermeable product that would be OK in the test assembly. Their new product literature states that the product “complies with NFPA 285” what does that mean? He is getting the test or engineering reports for me at this time to clarify this.
I called the rep for WR Grace and he had not heard of this issue either but with a little digging found a letter that stated that Grace perm-a-barrier and XPS insulation (Extruded Polystyrene) should be fine when testing assemblies per NFPA 285. Again – what assemblies were tested?
The Local reps for MCM panels were similarly in the dark and both are investigating.
I’m still investigating and I’m now broadening my reach.
WHAT are you folks doing?.
Here are the choices I have at the moment:
1. Stop using MCM panels
2. Specify only those air barriers approved by the MCM manufacturer (with test results required, of course)
3. Specify air barriers that will not generate flame or elevate the wall temperature beyond those listed in NFPA 285. Then make assumptions about possible test results and place the burden of testing upon the MCM fabricator (and add 30,000 dollars to your project cost.)
4. Make the Contractor submit similar tested systems to the Authority Having Jurisdiction AHJ for the hope of approval without new testing. |
Alan Mays, AIA
Senior Member
Username: amays
Post Number: 61
Registered: 02-2003
| | Posted on Monday, December 12, 2011 - 07:35 pm: | |
Marc, take a look at what is coming in the 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 a combustible water-resistive barrier shall be tested in accordance with and comply with the acceptance criteria of NFPA 285. |
Steven Bruneel, AIA, CSI-CDT, LEED-AP
Senior Member
Username: redseca2
Post Number: 309
Registered: 12-2006
| | Posted on Tuesday, December 13, 2011 - 12:22 am: | |
I remember a plan reviewer for California OSHPD way back in 1993 or so asking my firm to provide the edge of slab UL fire-safing assembly we intended to use for a high-rise hospital in LA.
Looking in the UL assembly book at that time, one found as I recall, 3 assemblies or so for things like brick veneer on a steel frame and metal deck high rise, and something with CMU and a veneer and one or two hyper specific wall assemblies where half the listed products were already out of production.
This was California, so that job, and many others, were put on hold until our various clients with their architects and clients, provided tests, or engineering judgements so the various projects could move forward. |
ken hercenberg
Senior Member
Username: khercenberg
Post Number: 112
Registered: 12-2006
| | Posted on Tuesday, December 13, 2011 - 11:59 am: | |
Alan, interesting that it states "combustible water-resistive barrier".
Marc, this may be why you received the comment about vapor permeable vs. vapor impermeable though I've heard it more as sheet vs. fluid-applied. My understanding is that foam insulation plus asphaltic sheet membranes equal too many sources for combustion. What product is Carlisle suggesting? |
Alan Mays, AIA
Senior Member
Username: amays
Post Number: 62
Registered: 02-2003
| | Posted on Tuesday, December 13, 2011 - 01:35 pm: | |
The 2012 IBC throws NFPA 285 into many other materials in chapter 14. They now include HPL to have the test. The MCM requirement has been in chapter 14 of the IBC since 2003. Prior to that they only had ACM and it did not reference NFPA 285 at all. That means that the testing requirement has been in existance for almost 10 years.
Ken, can you name me one "water-resistive barrier" that is not combustible? Will this new requirement throw all wall systems into the requirement to be a tested assembly? Will exterior wall systems need to be required to have an assembly test similar to UL tested assemblies? |
Marc C Chavez
Senior Member
Username: mchavez
Post Number: 427
Registered: 07-2002
| | Posted on Tuesday, December 13, 2011 - 02:02 pm: | |
the new carlisle costing is Barritech - NP for non-permeable vs their existing Barritech which is vapor permeable. |
John Bunzick, CCS, CCCA, LEED AP
Senior Member
Username: bunzick
Post Number: 1346
Registered: 03-2002
| | Posted on Tuesday, December 13, 2011 - 03:10 pm: | |
Marc, This is a big problem as you can see. It also applies to any wall assembly using foam insulation in the cavity, which could include brick veneer. The Boston chapter of the Building Enclosure Council (a committee of the Boston Society of Architects) has been looking at this for some time. We've done some research, such as finding out that there does not appear to be any fire loss history as a result of these constructions. The Boston BEC in conjunction with BETEC has raised significant funds to sponsor research into this issue, and ultimately to propose a change to the ICC to address this problem. Unfortunatley, under the best scenario that is 3 years away.
As far as the air barriers are concerned, the basic problem is that they could contribute fuel to a fire. Some research I had done a couple years ago suggested that this was especially true if the membrane was asphalt-based, but I don't know if the non-asphaltic products truly contribute less fuel. Our problem was that only the asphalt products (at least at that time) were impermeable.
I think the reason no one paid any attention to this was that it kind of snuck up on us all. Massachusetts has been building walls like this for a long time now, and when we finally adopted the IBC it put a monkey wrench into everything.
My personal opinion is that this provision of the code is a solution looking for a problem when it comes to MCM and cavity wall systems. |
Ronald L. Geren, AIA, CSI, CCS, CCCA, SCIP
Senior Member
Username: specman
Post Number: 977
Registered: 03-2003
| | Posted on Tuesday, December 13, 2011 - 06:54 pm: | |
This is something I have come across ocassionally. I've been informed that ICC is looking into the issue due to the cost of testing, the emphasis in the IECC for continuous insulation on exterior walls, and the superior performance of foam insulations over other types such as mineral wool.
I've had some success getting approval using foam based products that, by themselves, pass NFPA 285, and the application of materials over the insulation system, such as masonry, stone, or other noncombustible exterior wall coverings, does not alter the performance of the base insulation system. I've specified products like Centria's MetalWrap and similar products. These provide both an insulated layer and a water-resistive barrier.
I think what will occur is that through ICC's code development process the IBC will eventually incorporate prescriptive requirements that do not require the NFPA 285 test. This may take some initiative on the part of insulation manufacturers. There may also be a push to create tested UL assemblies and incorporate them into UL's fire-resistance directory.
Until then, we'll have to live with what the IBC provides, come up with alternative methods and materials, get the code to change, or persuade local jurisdications to create amendments that makes this requirement less restrictive.
Ron Geren, AIA, CSI, CCS, CCCA, SCIP
www.specsandcodes.com |
anon (Unregistered Guest)
Unregistered guest
| | Posted on Monday, February 06, 2012 - 01:19 pm: | |
ICC has a good white paper on this subject available online for all to read:
http://bsj.iccsafe.org/august/features/code_and_fire.html
The excerpts that I think most of us will be very interested in are:
"Even though a specific component of the wall system has met the requirements of NFPA 285, if additional combustible components are added to the wall assembly, then the assembly may no longer meet NFPA 285. For example, if a Metal Composite Material (MCM) by itself is successfully tested via NFPA 285, and if a CI such as foam plastic is added to the system, the new combination of materials may not meet the Code and the NFPA 285 performance requirements. The new combination wall assembly must be tested."
"In summary, with the increased use of CI, the NFPA 285 is an important test to evaluate and control the fire performance of foam plastic used in CI exterior walls such as that shown in the above illustration. The test applies to most exterior walls that contain foam plastic insulation in Types I, II, III and IV construction. The results of the test are limited to the assembly tested and 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."
Not a lot of wiggle room in this language, and Marc's question is still valid: How are all of these exterior wall systems getting by the code officials when they have clearly not all been tested as specific assemblies in accordance with NFPA 285? |
ken hercenberg
Senior Member
Username: khercenberg
Post Number: 158
Registered: 12-2006
| | Posted on Tuesday, February 07, 2012 - 01:53 pm: | |
In the diagram included in that link, the horizontal "Structural Zee Spacer" is continuous and probably constitutes a thermal bridge that would negate the continuous insulating properties of the assembly.
Alan, I don't know of any membranes not considered as addtional fuel to the fire.
The feedback we got from one XPS manufacturer was that their product could be used over most fluid-applied products but there were issues about self-adhering sheet (aka rubberized asphalt sheets). I requested but never saw NFPA 285 testing.
I keep hearing that testing has been done on this product or that, but I'm starting to feel like I'm on a snark hunt when trying to find a tested assembly. |
Alan Mays, AIA
Senior Member
Username: amays
Post Number: 70
Registered: 02-2003
| | Posted on Tuesday, February 07, 2012 - 03:07 pm: | |
"How are all of these exterior wall systems getting by the code officials when they have clearly not all been tested as specific assemblies in accordance with NFPA 285?"
In my opinion, the answer may lie in the fact that some building departments are not reviewing these items. If they are only accepting the drawings and not any specs, then how do they know that what is in the drawings meet the code required testing? Building departments seem to be mainly looking at life safety issues like type of construction, exiting, occupant load, exit travel, accessibility (if part of the adopted code), etc. They seem to be concentrating mainly on Chapter 4 - Chapter 11.
However, another question comes to mind if we were doing a little soul searching. How did we not discover this earlier? Who is at a bigger risk? The building official is not going to be at risk. The architect is going to be at risk. |
Mark Gilligan SE,
Senior Member
Username: mark_gilligan
Post Number: 453
Registered: 10-2007
| | Posted on Tuesday, February 07, 2012 - 05:53 pm: | |
Given the code adoption cycle the 2018 IBC is the soonest you will get that in the code. In California this will mean that the provisions does not become mandatory before Jan of 2020.
I believe that if we enforced the code strictly we could stop at least 90% of the construction |
Brian E. Trimble, CDT
Senior Member
Username: brian_e_trimble_cdt
Post Number: 55
Registered: 08-2005
| | Posted on Tuesday, February 14, 2012 - 09:52 am: | |
I don't think WE need to so any "soul-searching". This is another example of code-writing bodies with the best of intentions putting something in the code that doesn't make sense (in most cases). We know that plastic insulation burns. We know we need to protect life safety. What is the best way to protect people's lives if there were to be a fire? The testing that is currently being done will help us understand where the weak points really are. It may also show us if we need to be concerned about certain parts of building enclosure and how to detail it properly.
A somewhat similar parallel occurs in the masonry industry. Everyone knows that brick and block don't burn, but designers are always asking us (BIA) for UL numbers that they can refer to. The industry has not done any wideranging fire testing since the 1940s and 50s when much of the research was conducted. At that time, and since with actual performance, there wasn't a need to test every assembly because all masonry resisted fire in much the same way. So we don't use UL (and other) numbers for fire resistance, we use calculated fire resistance. This has been accepted by the codes and building code officials. This saves the industry from the expense of testing every permutation that designers come up with. The testing laboratories don't like that very much since they aren't being paid to run all of these tests. So in some cases there could be some common features of walls where we wouldn't have to test every assembly. Making one assumption may be enough for a whole range of products or assemblies. The problem is the codes haven't caught up or been asked to come up with a solution.
I think Mark is right, 90% of construction could be affected by this somewhat innocuous ruling. For myself, I have NEVER heard of a brick wall with rigid insulation in the cavity contributing to a fire. I await word of someone who has. |
Marc C Chavez
Senior Member
Username: mchavez
Post Number: 440
Registered: 07-2002
| | Posted on Tuesday, February 14, 2012 - 12:21 pm: | |
My local Carlisle waterproofing rep just sent me a copy of a letter sent from Hughes Associates, Inc. to the Extruded Polystyrene Foam Association. Entitled “Analysis and Extension of NFPA 285 tests HAI Project No.: 1JJB00060.001” They have summarized tests from several locations and made additional small scale tests on various "weather resistive barriers" . The engineer then goes on to issue his judgment that:
“Based on the results of these tests, additional small-scale tests of the weather-resistive barriers and my experience with the NFPA 285 fire test, it is my judgment that the various configurations of exterior walls described in Table II will meet the performance requirements of NFPA 285.”
This is the best I can hope for at this time without having EVERY exterior assembly (in Types I II III IV buildings) containing combustible materials tested when used with an air barrier (as if I have ANY wall assembly with out an air barrier.
I have alerted the architects in our offices to be aware of this issue. My Building Insulation section (as the CI is found there) will reference the requirement for the NFPA 285 testing. My Air Barrier section will also require it. We will offer up this letter and other similar notes to code officials as we can. HOWEVER, the onus will be on the manufacturer/contractor to cough up 30K for a test or convince the AHJ that things are OK – The upshot is that I will probably do two things, move to mineral fiber insulation where I can and use air barrier products that have as much proof of non-combustibility as possible.
Remember this issue came to me from the air barrier side NOT the insulation side. If I have an air barrier material that is NOT a plastic and NOT combustible then I do NOT have to test the wall because I’m NOT in chapter 26!
PS
I agree with what Brian stated above. The ICC references tests right and left without (it seems) understanding of the wide ranging effects that reference can have. The test is just a test.
Additional information
http://www.centriaperformance.com/pdfs/Beitel%20Spiewak%20Fire%20Code.pdf
http://www.foamsheathing.org/images/TM_NFPA_285_Assemblies.pdf
http://www.icc-es.org/Criteria_Development/1102-pre/Memos/13_AC12_Memo.pdf
I hope that helps everyone. I don’t know how to post the full letter that I received. But here is the table of air barriers.
Weather-resistive Barrier applied to Gyp Sheathing
Green Guard®Max Building Wrap - Pactiv
WeatherMate™ or WeatherMate™Plus – Dow Chemical
Tyvek® CommercialWrap® - Dupont
Backstop® NT – Dryvit
Barritech™ VP – Carlisle
AIR-SHIELD™ LMP (Black only) - W. R. Meadows
Perm-A-Barrier® VPS - W.R. Grace
Weather-resistive Barrier applied to Foam insulation
Green Guard®Max Building Wrap – Pactiv
WeatherMate™ or WeatherMate™Plus – Dow Chemical
Tyvek® CommercialWrap® - Dupont |
anon (Unregistered Guest)
Unregistered guest
| | Posted on Tuesday, February 14, 2012 - 05:07 pm: | |
anyone that wants the letter can get it here:
http://www.icc-es.org/Criteria_Development/1102-pre/Responses2/13_AC12.pdf |
Marc C Chavez
Senior Member
Username: mchavez
Post Number: 441
Registered: 07-2002
| | Posted on Tuesday, February 14, 2012 - 05:50 pm: | |
similar but not the same letter. the one I got had a table of potential assemblies and the "tested" air barriers |
anon (Unregistered Guest)
Unregistered guest
| | Posted on Tuesday, February 14, 2012 - 05:15 pm: | |
apologies, not the letter Marc references, I hit the button prematurely, but the link I provided does offer some additional information to those interested. |
J. Peter Jordan (Unregistered Guest)
Unregistered guest
| | Posted on Wednesday, February 15, 2012 - 09:35 am: | |
I have been thinking about this issue and tend to agree with Brian about whether or not this is a "real" issue or a code issue that is based on a percieved issue. Most code implementations and revisions are reactionary; they are responding to failures of some sort. While model building codes probably should be a bit more proactive, this particular one seems to be somewhat speculative and even specious. I am simply not sure of the context from which these issues arise.
I do see problems with EIFS (which is where I suspect this originates, and I am not sure about using this in metal wall panel assemblies, but I simply fail to see how plastic foam insulation and air barrier products can be a problem when incorporated into exterior wall assemblies with masonry veneer, cement plaster finish, or stone/ceramic veneers adhered to substrates. This assumes that there is a layer of gypsum sheathing and interior gypsum wallboard (or similar stuff) between these products and the building interior.
Ron... Can you shed some light on this? |
Randall A Chapple, AIA, SE, CCS, LEED AP
Senior Member
Username: rachapple
Post Number: 50
Registered: 12-2005
| | Posted on Wednesday, February 15, 2012 - 06:44 pm: | |
There was a resent fire in China where a rigid insulation was being installed on the exterior of the building and the building caught fire during construction and was quickly engulfed in flames. I do not know if this had any influence on the change but it was a dramatic fire. |
Marc C Chavez
Senior Member
Username: mchavez
Post Number: 442
Registered: 07-2002
| | Posted on Wednesday, February 15, 2012 - 07:39 pm: | |
nope
this has been in the code for quite a while - it's just the addition of the Air barriers that made it pop to the foreground and THEN you start reading NFPA 285 and go nuts. |
J. Peter Jordan (Unregistered Guest)
Unregistered guest
| | Posted on Thursday, February 16, 2012 - 09:55 am: | |
Marc; you needed to read NFPA 285 to go nuts? |
anon (Unregistered Guest)
Unregistered guest
| | Posted on Monday, July 22, 2013 - 05:26 pm: | |
Does anyone have information on a system similar to Centria's "MetalWrap?" I want at least two credible systems in my spec, if at all possible.
Thanks |
Ronald L. Geren, AIA, CSI, CCS, CCCA, SCIP
Senior Member
Username: specman
Post Number: 1129
Registered: 03-2003
| | Posted on Monday, July 22, 2013 - 05:46 pm: | |
When I specified Centria's MetalWrap as a basis-of-design product, I found that Insulated Panel Systems, Kingspan, and Metl-Span had very similar products.
Ron Geren, AIA, CSI, CCS, CCCA, SCIP
www.specsandcodes.com |
anon (Unregistered Guest)
Unregistered guest
| | Posted on Monday, July 22, 2013 - 05:50 pm: | |
I think I found the Kingspan system, looks like they call it "KarrierPanel Universal Barrier Wall System"
thanks |
ken hercenberg
Senior Member
Username: khercenberg
Post Number: 561
Registered: 12-2006
| | Posted on Monday, July 22, 2013 - 06:03 pm: | |
Ron, have these others now included NFPA 285 test data when used as a backup system? Last time I looked at listing them as an alternative to the MetalWrap they didn't really have the documentation.
For a project where we opted to pursue use of a unitized curtain wall for virtually the entire exterior skin, we tried listing a panel from Mapes that could be glazed in as a backup panel. We couldn't really make the costs work with either the Mapes or the MetalWrap (which didn't allow for the glazing-in option). Just as well; based on a closer look at how the total system detailing came out, it didn't really work as true continuous insulation anyway. We had to pursue other options. Still, I like the idea if you can make the detailing work. |
Ronald L. Geren, AIA, CSI, CCS, CCCA, SCIP
Senior Member
Username: specman
Post Number: 1130
Registered: 03-2003
| | Posted on Monday, July 22, 2013 - 06:26 pm: | |
Kingspan and Metal-Span have products that have been tested per NFPA 285 (Metl-Span has an ICC-ES evaluation report). NCI Insulated Panel Systems does not, but we included them anyway, as long as they provided the testing prior to submitting submittals for the product.
Ron Geren, AIA, CSI, CCS, CCCA, SCIP
www.specsandcodes.com |
Louis Medcalf, FCSI, CCS
Senior Member
Username: louis_medcalf
Post Number: 16
Registered: 11-2010
| | Posted on Thursday, August 15, 2013 - 02:59 pm: | |
When researching use of MCM cladding, technical staff at each of the 3 major manufacturers told me their standard core panels will not pass an NFPA 285 test. Have to use their fire-resistant core panels or solid aluminum plate.
The concern is that in a fire, aluminum windows melt allowing fire to get into the construction of the exterior wall with the possibility of propagating through the wall to the next higher story [simplified]. That's why one-story buildings are exempt from the requirement for NFPA 285 testing. NFPA 285 test assemblies are 2-stories with a window opening on the lower story.
The question is whether there is really a loss history in the US that justifies this code requirement and the extension to all combustible products in the exterior wall construction, regardless of fuel contribution, and the related cost to US commercial construction. Does an air barrier that is typically not more than 40 mils really contribute a significant amount of fuel to a fire? |
Edward J Dueppen, RA, CSI, CCS, LEED AP
Junior Member
Username: edueppen
Post Number: 2
Registered: 08-2013
| | Posted on Thursday, August 15, 2013 - 03:16 pm: | |
Louis - I need to understand what you mean about "that's why one-story buildings are exempt from the requirement for NFPA 285 testing". While NFPA 285 is a multistory test, the IBC enforcement of NFPA 285 does not exempt 1-story buildings.
A few weeks ago I confirmed directly with ICC that 1-story buildings are not exempt. The closest thing to an exemption is IBC 2603.4.1.4. which governs 1-story buildings, but it requires sheet metal to be placed over the insulation in the wall cavity. I have never heard of this being performed.
You do make an excellent point about "loss history". Why have the code bodies decided to solve a problem that does not appear to exist? |
Ronald L. Geren, AIA, CSI, CCS, CCCA, SCIP
Senior Member
Username: specman
Post Number: 1135
Registered: 03-2003
| | Posted on Thursday, August 15, 2013 - 03:18 pm: | |
The test does not include an actual window, just an opening. Therefore, the cladding must have a protection system for the opening and not rely on the window to protect it.
I recently wrote an article regarding NFPA 285: NFPA 285: Flame Propagation in Exterior Walls.
Ron Geren, AIA, CSI, CCS, CCCA, SCIP
www.specsandcodes.com |
Ronald J. Ray, RA, CCS, CCCA
Senior Member
Username: rjray
Post Number: 119
Registered: 04-2004
| | Posted on Thursday, August 15, 2013 - 04:13 pm: | |
Ron, I could not get the link to the article to work. |
Ronald L. Geren, AIA, CSI, CCS, CCCA, SCIP
Senior Member
Username: specman
Post Number: 1136
Registered: 03-2003
| | Posted on Thursday, August 15, 2013 - 04:26 pm: | |
Try this one: NFPA 285: Flame Propagation in Exterior Walls
Ron Geren, AIA, CSI, CCS, CCCA, SCIP
www.specsandcodes.com |
Ronald J. Ray, RA, CCS, CCCA
Senior Member
Username: rjray
Post Number: 120
Registered: 04-2004
| | Posted on Monday, August 19, 2013 - 09:10 am: | |
Ed,
I believe the sheet metal covering over the foam plastic insulation is only required IF one desires to not use the thermal barrier required by section 2603.4.1.
Interesting that the Code does not mention if the insulation is required to be covered on one or both faces.
Thanks Ron, that second link worked. Great article. |
Ronald L. Geren, AIA, CSI, CCS, CCCA, SCIP
Senior Member
Username: specman
Post Number: 1137
Registered: 03-2003
| | Posted on Monday, August 19, 2013 - 11:15 am: | |
Ron, you're correct. The metal is in lieu of a thermal barrier that is required per Section 2603.4. As Section 2603.4 states, the thermal barrier separates the interior from the foam plastic. Therefore, the requirement does require application of the metal to the exterior side of the foam plastic.
Ron Geren, AIA, CSI, CCS, CCCA, SCIP
www.specsandcodes.com |
Edward J Dueppen, RA, CSI, CCS, LEED AP
Member
Username: edueppen
Post Number: 3
Registered: 08-2013
| | Posted on Monday, August 19, 2013 - 11:44 am: | |
Ron (or others),
The question remains whether NFPA 285 compliance is required for one-story buildings. Some sources have repeatedly indicated that NFPA 285 compliance is NOT required for one-story buildings. But as I confirmed with ICC, the only exception for one-story buildings is the Exception to 2603.5.5. This Exception, while exempting the building from NFPA 285, requires compliance with 2603.4.1.4 which, among other requirements, prescriptively requires sheet metal be placed over the insulation. This sheet metal installation in a wall cavity is a practice that I have never heard being performed and does not seem practical. Therefore, reflexively, a one-story building would have to comply with IBC 2603.5.5 (NFPA 285).
If this line of thinking is incorrect, or if there is a practical metal-clad insulation product, please let me know! |
J. Peter Jordan
Senior Member
Username: jpjordan
Post Number: 602
Registered: 05-2004
| | Posted on Monday, August 19, 2013 - 12:10 pm: | |
If I recall correctly, Type 5 buildings are exempt from this requirement. Since many Type 5 buildings are single-story buildings, this may be where the impression that such buildings are exempt comes from. |
Ronald L. Geren, AIA, CSI, CCS, CCCA, SCIP
Senior Member
Username: specman
Post Number: 1138
Registered: 03-2003
| | Posted on Monday, August 19, 2013 - 12:29 pm: | |
Ed:
ICC is correct. Section 2603.5 is titled "Exterior walls of buildings of any height," which means that one-story buildings are required to comply with the NFPA 285 testing. The exception to Section 2603.5.5 (the requirement for NFPA 285 testing) references complying with Section 2603.4.1.4 for one-story buildings. As I stated, this is a subsection that is essentially an exception to the requirement for a thermal barrier that separates the interior from the foam plastic in the exterior wall. The Code and Commentary mentions that this is for the metal building industry for buildings that may not use gypsum board on the interior. Thus, the only separation between the foam plastic and the building interior is the sheet metal; thereby adding the requirement for the sprinkler system to provide the added protection for equivalency.
The confirmation you received from ICC is just a staff opinion and not a vetted formal interpretation. Although staff opinions carry some weight, they don't have the level of authority that a full committee interpretation would provide.
I admit this is an imprecise requirement. The use of "foam plastic is covered" in Section 2603.4.1.4 does not stipulate if the cover is to completely encapsulate the foam plastic. That may be the intent, but as specifiers we know that intent does not a requirement make.
I could probably get an alternate means and methods approval by using the sprinkler system per Section 2603.4.1.4 and a gypsum board thermal barrier to avoid the NFPA 285 for a one-story building using the language of Section 2603.4.1.4 against itself by pointing out that full encapsulation of the foam plastic is not stated--just that it is covered from exposure on the interior side (the purpose of a thermal barrier). Since the concern of Section 2603.4.1.4 is the separation of the foam plastic from the interior, the use of gypsum board, per Section 2603.4, will provide that barrier, thus negating the need for the sheet metal. Therefore, a sprinklered one-story building (with either sheet metal or 1/2-inch gypsum board between the foam plastic and interior) would not be required to be tested per NFPA 285.
As to your last statement about a practical metal-clad insulation product, I mentioned several manufacturers above that provide metal insulated panels that can be used.
Ron Geren, AIA, CSI, CCS, CCCA, SCIP
www.specsandcodes.com |
Margaret G. Chewning FCSI CCS
Senior Member
Username: presbspec
Post Number: 260
Registered: 01-2003
| | Posted on Thursday, September 04, 2014 - 12:10 am: | |
Hey Ya'll
I've had a question posed to me that I've not had to answer before. I have a USACE project where the Exterior Enclosure Assembly is field installed utilizing various components. The components from the inside outward are as follows: (a) 6” metal stud framing, (b) ½” exterior gypsum board sheathing, (c) air barrier membrane, (d) foam plastic insulation board (extruded polystyrene), and (e) metal panel siding. There is no plastic material imbedded within the metal panel siding material. The question is: who would be the “manufacturer” that has responsibility to have the NFPA 285 test performed?
Currently our Section 07 21 13 - Board and Block Insulation only references ASTM E 84 criteria of FSI at 25 or less and SDI at 450 or less. There is not any reference to the NFPA 285, unless it is just through the general reference to the IBC criteria.
Thanks
Margaret |
William C. Pegues, FCSI, CCS
Senior Member
Username: wpegues
Post Number: 919
Registered: 10-2002
| | Posted on Thursday, September 04, 2014 - 12:39 am: | |
Margaret,
Many of the Air Barrier manufactures have taken the lead on this. Though any of the material manufacturers could do so, its actually not anyone's requirement or responsibility. It just makes good business sense that if you market a combustible product for wall assemblies, that you perform as wide a testing as possible for the kinds of applications your products are likely to encounter.
Now, here is the rub - many of the architectural reps for these products don't know (because they have not been told) that there is information available that tells exactly what materials their product has been tested with and in what configurations. About a year ago now I went to Henry related to what tests they may have performed. Initial response was that there was no list, but that they would check. A short time later I was given a nice brochure that had a printing date of close to a year earlier that listed whole groups of products and manufacturers.
So I went to the Tyvek people and asked them - they said the same thing, and then a week or so passes and I get another nice brochure that shows a wide range of products they have tested with.
This proceeded down the list of other air barrier manufacturers. I remember one that shall remain nameless that when I asked about it was fairly sure that no such lists were being developed. This was one of the more competent reps that I have known for years and respect. So I handed them a brochure from a competitor and said he could keep it. A week or so passed and I got emailed a brochure that bore a printing date of close to a year earlier that ended up being one of the larger comprehensive lists of products from other manufacturer's tested with this air barrier.
I have not checked in about 6 months or so now, but at that time, none of these were available or even referenced at all on the company web sites. It seems to me that most web sites, even for very technical information, are controlled by the corporate marketing departments. And to marketing types, they think that the professional side wants to see pretty pictures or 'gee wiz' type performance information.
Now, one of the short comings for these brochures is that they are only the introduction to what we really need. Well, not what we need but what the project architect needs - that is, the details. Not only do the products in the wall assembly have to be listed as having been tested as an assembly, but the details for the project have to be drawn matching exactly the details used in the assembly tests. Not everyone realizes that, and many of the assembly tests performed ended up with some detailing requirements that have yet to make it into the manufacturer's standard details.
So, language wise for part 3, might include that where details as shown varies from the manufacturer's required detail for compliance with NFPA 285, the manufacturer's detail requirements shall govern.
That might result in some surprises if a PA does not really check into this issue, but better to have to deal with a surprise than to have to tear down a wall. Or worse, no one not even inspectors may realize its not in compliance and after some fire an investigation reveals that the wall is not in compliance with the manufacturer's assembly requirements.
William
William C. Pegues, FCSI, CCS, SCIP Affiliate
WDG Architecture, Washington, DC | Dallas, TX |
Sheldon Wolfe
Senior Member
Username: sheldon_wolfe
Post Number: 786
Registered: 01-2003
| | Posted on Thursday, September 04, 2014 - 12:57 am: | |
Not much choice but to look for an assembly that has passed the test. So far, insulation manufacturers are leading the way, including a variety of air barrier materials in their tests, but a few other manufacturers have tested their products. My understanding is that because it's an assembly test, you must use exactly the same materials used in the test, and your details must be exactly the same.
Search for "Dow NFPA 285" "Owens Corning NFPA 285" "Henry NFPA 285" and so on, perhaps starting with the metal panel you want to use. |
J. Peter Jordan
Senior Member
Username: jpjordan
Post Number: 762
Registered: 05-2004
| | Posted on Thursday, September 04, 2014 - 07:50 am: | |
This is a moving target that can be confusing. UL does not maintain a directory of listed assemblies so manufacturers are the only source of information which may not have the same weight of authority. Because the IBC requires testing, but does not require a "listed assembly", it should be easily possible to get a variance based on an engineering judgement. It seems to me to leave a lot to the discretion of the AHJ. |
Sheldon Wolfe
Senior Member
Username: sheldon_wolfe
Post Number: 787
Registered: 01-2003
| | Posted on Thursday, September 04, 2014 - 08:38 am: | |
http://database.ul.com/cgi-bin/XYV/template/LISEXT/1FRAME/index.html?
In "UL Category Code" enter FWFO
Not much there yet; mostly brick cladding with a few Reynobond assemblies.
Our best results come from starting with the cladding manufacturer. As William notes, the fact that a company has passed the NFPA 285 test is only the beginning. Only one panel may have been tested, and the assembly that passed may use materials or details other than the ones you usually use, e.g., mineral wool instead of rigid foam, a one-inch air space instead of two, steel flashing, etc. |
Sheldon Wolfe
Senior Member
Username: sheldon_wolfe
Post Number: 788
Registered: 01-2003
| | Posted on Thursday, September 04, 2014 - 08:44 am: | |
The code official does have discretion, so what works in one jurisdiction may not work in another, or may not work in the same jurisdiction if the code official changes, so don't assume anything. |
Margaret G. Chewning FCSI CCS
Senior Member
Username: presbspec
Post Number: 261
Registered: 01-2003
| | Posted on Thursday, September 04, 2014 - 09:08 am: | |
Thank ya'll for the advice above; however this is already under contract on an Army garrison. The Exterior Enclosure Assembly is a "delegated design" regarding the reinforcement within the curtain wall components and likewise the infill metal stud arrangements behind the metal panels.
My question is who should perform the test on this system to meet NFPA 285? |
William C. Pegues, FCSI, CCS
Senior Member
Username: wpegues
Post Number: 920
Registered: 10-2002
| | Posted on Thursday, September 04, 2014 - 09:36 am: | |
Margaret,
That's just it. No one is required to have performed the test, its not an obligation at all. You just can't use the material if it has not past the test.
Some manufacturers have simply tested their own material with only other non-combustible materials. So, you could use it, but with nothing else that is combustible in the wall.
And there is no way in the documents that you can require that a specific assembly be tested - that's not going to happen time wise or cost wise by anyone...and the details will be whatever the manufacturer of the product creates, and that the job documents must follow.
So, its something that you have to determine now, before the materials are selected, as to what and whose materials can be used - and then they need to be put into your wall assembly as detailed when tested.
Your question is being posed as though an assembly is designed, shown/detailed and specified, and now someone must be required to test it. That's not going to happen. Its not like curtain wall or window mockup testing. Your products have to be tested before they are designed, and the design, detailing and specifying must follow the assembly tested.
William C. Pegues, FCSI, CCS, SCIP Affiliate
WDG Architecture, Washington, DC | Dallas, TX |
Edward J Dueppen, RA, CSI, CCS, LEED AP
Senior Member
Username: edueppen
Post Number: 11
Registered: 08-2013
| | Posted on Thursday, September 04, 2014 - 09:57 am: | |
Margaret,
It seems to me that the best route now might be to try to obtain an engineering judgement that would be acceptable to all of the parties involved. Hughes Associates is one group that I have heard of offering this service. |
Sheldon Wolfe
Senior Member
Username: sheldon_wolfe
Post Number: 789
Registered: 01-2003
| | Posted on Thursday, September 04, 2014 - 10:05 am: | |
We have a client that included the NFPA 285 test as part of construction. Strange? Not if the company is using its own building to test some of its new products before production. Possible solution for your project? Not likely. |
Margaret G. Chewning FCSI CCS
Senior Member
Username: presbspec
Post Number: 262
Registered: 01-2003
| | Posted on Thursday, September 04, 2014 - 08:53 pm: | |
Thank you to all of you who contributed to answering my question. A decision has been made to change the exterior insulation product (foam plastic) to Mineral wool exterior insulation to avoid any additional project schedule delay that would entail if we had to have the foam components researched and evaluated.
Look to see you all next week. THANKS |
John Bunzick, CCS, CCCA, LEED AP
Senior Member
Username: bunzick
Post Number: 1591
Registered: 03-2002
| | Posted on Monday, September 08, 2014 - 10:38 am: | |
Well, the only entity in the position to pull all the others together for a test is the general contractor. You can be sure that they did not include testing, however. Even if the budget could be obtained, the time to schedule and complete the test, which could be many months, would likely be more of an obstacle than the cost. |
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