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Community and Q&A

Closed cell foam roof install issues

Julian Lockhart | Posted in Energy Efficiency and Durability on

I had closed cell foam applied to my roof. It was supposed to be 3” but it is typically 4” – 6″ or more. 


I had had the foam tested and the density was 1.94, 1.86 and 2.16. The open/closed cell content was 66%,54% and 84%. I would guess that the open cell content is going to make the foam not as structurally sound as well as diminished R value.


What’s the best way to determine if the R value is there for the roof?

Would you have the foam replaced or ask for a rebate?






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  1. John Clark | | #1

    R-value of ccSPF: 6.5/inch.
    Your density while on the low side is close to the typically stated range of 2-3lbs.
    For comparison ocSPF(Open-Cell Spray Foam) has a density of .25 - .75. R-Value of 3.7/inch.

    My Opinion,

    As for the open cell content, only the manufacturer of the foam would know what amount of variation is acceptable. Applying spray foam is just as much art as it is science (chemicals are mixed on site, are sensitive to temp as well as moisture). I wouldn't get worked up over differences in thickness which exceed the thickness you paid for. This goes to your suggestion for a rebate. You paid for a 3-inch lift and it looks like you received more than what you paid for.

    Q: Curious why did you have the testing done in the first place?

  2. Julian Lockhart | | #2

    I was told < .90

    I was adding a rat run and cut out the foam and noticed that it had lots of blowholes and was easier to remove than I would have expected. Somewhat closer to the feel of open cell foam.

  3. Expert Member
    Zephyr7 | | #3

    Might have been applied a bit too hot. If you don’t have any discoloration or gooey spots you’re probably ok though. Is it spongy at all? CcSPF should be fairly hard, you shouldn’t be able to easily push your finger into it.


  4. Julian Lockhart | | #4

    Most samples are spongy with elongated cells. Large pieces are easily broken apart. Also have some where the lift separate easily.

    I was sold on the additional structural benefits of cc. It seems that that’s going to be diminished.

    I would really like to have a way to establish if the r value is there.

    I also want to be certain that this foam that probably was applied too hot and with not enough dwell time will not deteriorate (faster) over time.

    1. Expert Member
      Zephyr7 | | #5

      I wouldn't worry too much about the structural part. ccSPF does help, but I've always thought of it as helping to make a structure more rigid, not necessarily stronger in the load bearing sense.

      The bigger concern is if your spray foam is going to properly insulate. ccSPF should be hard, and very difficult to break apart. Small pieces when broken will make a SNAP, like breaking a small piece of wood. Lifts should be glued together so strongly that they act as one piece.

      I can't be certain if it was an application temperature issue, but something sounds to be off. Have you tried contacting the manufacturer? They should at least be able to tell you if it sounds like a bad application.


      1. Julian Lockhart | | #7

        Thanks. A lot of the foam does not snap but it kind of rips

        The manufacturer was the tester and they recommended all sample areas to be replaced( and areas with similar characteristics).

        The problem is the foam is mostly consistent and with the issues described. I am leery of asking them to remove so much.

        Ive read about taking IR temp readings and calculating the r value that way. but it seems unreliable..

        I just had an idea . . . Remove a 2x2 section and place xps foam layers to r20 and read the temp with ir.

        1. Expert Member
          Zephyr7 | | #8

          Use an IR camera and not an IR thermometer. The IR camera will show a picture with color gradients representing thermal gradients. Any poorly insulated spots will be easy to see and this method will be WAY easier and faster than trying to use a simple IR thermometer.

          If the manufacturer is recommending replacement I’d be inclined to go with their recommendation. If the lifts are in layers that may separate in the future, that’s a big problem. You may also have undetected voids, and I’m not sure how this will all effect moisture migration in the foam which is a big concern with a roof assembly.

          The way you’re describing the physical feel of the spray foam sounds more like open cell than closed cell spray foam. Open cell foam has been known to have moisture problems when used in roof assemblies.


  5. Jon R | | #6

    I'd guess that your extra thickness will more than make up for the diminished R/inch value. But it would take a R value test to be certain.

  6. Expert Member
    Akos | | #9

    I've had similar looking foam when using the two part kits near the end when one starts running out. My guess is the mix is wrong when it was applied. You are lucky that it went that way, going the other way on the mix causes it to ooze and turn into an ugly mess.

    The crumbly foam seems to hold up well enough, just not as solid as a proper mix. I would check some of the other ares to make sure you don't have any un-reacted materials buried under the spray foam.

    Overall, your spray foam guy screwed up, that should not happen. Some people had issues with chemical smell from improper foam installs down the road, so it might be worth to talk to the manufacturer before covering it up.

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