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Community and Q&A

A statement from Icynene

Martin Holladay | Posted in Building Code Questions on

Those following the spirited discussion that followed the posting of “It’s OK To Skimp On Insulation” may be interested to learn that a senior representative from Icynene has posted a response.

Paul Duffy, Icynene’s vice president for engineering, posted his response today (Feb. 11 at 1:52 pm). Find it here:

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  1. homedesign | | #1

    Li Ling Young:
    "It's possible the whole explanation for encouraging installations no thicker than 5" is that the product has not been tested for flame and smoke at any thickness other than 5". Claiming 5" is sufficient for energy conservation may just be a dodge to avoid questions about code compliance."

    I was very surprised to read Li Ling's comment concerning maximum foam thickness.
    This was news to me!
    Is it true that Icynene(Open Cell) is NOT code compliant beyond 5.5"?
    I tried to ask Paul Duffy(Icynene Engineer/spokesman) on your blog and so far he has not responded.
    I'm sure that he is paying close attention to your His failure to comment has to make me wonder?????

  2. GBA Editor
    Martin Holladay | | #2

    According to my research, it was indeed true — at least as of April 2008, when my article on the topic was published — that the Evaluation Service Report (from ICC-ES) for Icynene insulation evaluated the product only up to a maximum permissible thickness of 5 1/2 or 6 inches. Beyond a thickness of 5 1/2 to 6 inches, the foam has not be evaluated for smoke emissions or flame spread.

    If Icynene has submitted its insulation to further testing, and has therefore released an updated Evaluation Service Report that would allow thicker Icynene installations, I haven't seen it. Like you, I invite Paul Duffy to share more information on the topic.

  3. GBA Editor
    Martin Holladay | | #3

    More information:
    I have located the latest Evaluation Service Report. It's here:

    The ESR reports that Icynene's surface burning characteristics have been tested in accordance with ASTM E84 only up to a thickness of 5 1/2 inches.

    However, the ESR now includes a variety of tested assemblies — tested for one-hour fire resistance, that is, not surface burning characteristics — that include Icynene that is up to 10 inches thick (R-37).

    A couple of caveats:
    1. Builders can only depend on these test results (and use them to convince a local code official) if they build assemblies that exactly match the assemblies described in the ESR.

    2. Most of these tests include intumescent coatings, a controversial category of products that not all fire experts trust. For more on the controversies surrounding intumescent coatings, see the April 2008 EDU article.

  4. Riversong | | #4

    That's interesting. That ESR was issued May 2009 for a thickness of 5.5". A spec sheet on Icynene LD-C-50 dated November 2009 lists the ASTM E84 results for 5" thickness as 20/400 flame spread/smoke development. The ESR you linked to for 5.5" tests at 25/450. So even an additional ½" thickness seems to significantly increase fire & smoke ratings.

  5. homedesign | | #5

    Still no comments from the Foam industry.........??????
    Maybe Li Ling Young was Correct.

    I always assumed that the foam companies discouraged thick application because of cost...
    I had no idea that it may be illegal or a safety concern.

  6. homedesign | | #6

    Did Paul Duffy answer my question or Dodge my question?

  7. GBA Editor
    Martin Holladay | | #7

    The answer to your question is highly technical -- and I was kind of hoping that Paul Duffy would answer to save me the trouble. Seeing that he hasn't, I've gone ahead and written an answer to your question. It's posted on the "It's OK to Skimp on Insulation" page:

  8. Riversong | | #8


    I've added this question to your blog, but let me repeat it here as I'm more likely to see the answer as I don't surf the blogs unless linked to them (and there's no provision for for email notification of new messages or blogs - you can add that to the list of necessary website improvements).

    What's the controversy surrounding intumescent coatings?

  9. GBA Editor
  10. Paul Duffy | | #10

    Hello Martin,

    Sorry I have not checked into this discussion for a while. I have been travelling and in limited availability. I see that the discussion has morphed into a number of questions about fire testing. I apologize if this response is a wee bit late.

    You and others appear to have captured most of the key points…

    • ASTM E-84 is a good test for qualifying materials but the physical limitations of the test apparatus/procedure limits us from adequately testing thicker samples of foam.

    • For thicker assemblies, ICC-ES uses NFPA 286 to qualify Icynene wall assemblies at 7 ½” in the walls and 11 1/2” in enclosed (cathedral-type) ceiling applications.

    • In open attics, the so-called Modified NFPA 286 qualifies foam on the underside of the roof deck to depths of 14”.

    This is what is contained in the latest ESR reports for our light density foam products.

    Frankly, in earlier versions, we were not seeing the demand for such R-values because the air sealing improvement was such a remarkable performance improvement for most builders.

    As to the controversy surrounding attic and crawlspace test procedures, some folks argue that the previous test procedure, more accurately represented “end use conditions” versus the current procedure. This is somewhat academic in that the current AC 377 Acceptance Criteria are what we must all adhere to. All of our products have been tested and passed according to the current procedures.

    I trust this clarifies the current status of approve test reports.

    Paul Duffy, M.A.Sc., P.E.
    Vice President, Engineering
    Icynene Inc.

  11. homedesign | | #11

    Paul Duffy: "In open attics, the so-called Modified NFPA 286 qualifies foam on the underside of the roof deck to depths of 14”."

    Paul Duffy,
    I am glad you have returned to the discussion.

    Image #8 in the following blog depicts an Icynene application in an open attic.

    The foam appears to be less than 14" and it will most likely not be covered with drywall.

    Is this a case where the intumescent coating is required?
    If so...Does Icynene provide and install the coating as a matter of course?
    Or is it up to the builder to somehow "know" that the coating is required and request the coating?

  12. Anonymous | | #12

    The modified NFPA 286 test is only good until the end of December 2010. The new AC-377 test ,effective January 1 2011, will require any foam that does not pass the test uncovered to be covered with an ignition barrier. My guess is that none of the open cell manufactures will be able to pass this test without an ignition barrier.

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