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Open Cell Off-Gassing – Contractor Wants to Remove and Spray Closed Cell Over

acama23 | Posted in Expert Exchange Q&A on

Hello! I had a contractor spray our attic on 2/3/23. They used closed-cell and open-cell foam in our attic. The open cell was used behind knee walls in our attic and in some hard to reach areas to make sure the crevices were all covered. Basically, they sprayed some areas blind.

Since the install we have had a bad odor coming from the foam. We noticed the open-cell was the culprit due to the smell seemingly coming from there when we went to smell it.

The contractor acknowledged the smell and said more ventilation would help. We ran an exhaust for a weekend and then turned it off to check. The smell was still there. 

At this point it is mid-February and the smell is still present. My wife and I both got a headache after being in the space so we decided to leave a few weeks back.

We had an indoor air quality test done (TO-15 VOC) test performed that showed high levels of 1-4 Dioxane and a Total VOC of 1900 ug/m3. The results combined with the health symptoms and odor were enough for us. 

It has been over a month now and the contractor recently suggested removing the open-cell and spraying over it with closed cell foam to remove any issues. Is this a reasonable suggestion? My hesitation is that removal will cause a host of dust and other bits as well as potentially bad odor. The other hesitation is because some of the areas were sprayed “blind” and may be completely inaccessible due their location.

I’m at a cross-roads being out of my house with my 2 kids and all. I’m just trying remedy the situation as best as possible. I would add that the closed cell they sprayed in the attic has no odor.

I appreciate any and all help.

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  1. charlie_sullivan | | #1

    What should happen is that the contractor's insurance should pay for you to buy an equivalent house and pay for your relocation to that house. Then they can try whatever they want to remediate it without affecting you or your family. I doubt you'll get them to agree to that, but I think it's worth discussing that as an option, probably working through a lawyer. That might lead to some other options starting to seem more feasible, like removing part or even all of the roof to access the problem areas and remove the problem foam and make sure it's all removed.

    1. acama23 | | #2

      Hey. Thank you for your reply. I didn't want to jump to lawyer and I don't even know how all that works or where to start. The environmental services company that did the testing proposed some lawyers.

      To be honest, our contractor didn't budge much until I left a voicemail saying that if I don't see some action we'll be contacting legal services.

      I don't want to overreact but also don't what to minimize the disruption of life and the overall issues here. I mean, is it that bad? I felt symptomatic being up there as well as someone else. I know that with an increase in ambient temperature off-gassing is likely to get worse.

      There is almost no way to guarantee complete removal without ripping stuff out (rafters / decking / etc.).

      I'm leaning towards replacing the roof. Just don't know where to start. Thank you and any other advice is great.

      Also, how or why did you insist what you did?

      1. charlie_sullivan | | #3

        I feel bad about my response because it's not very helpful. Where it comes from is having seen lots of discussions where people are reluctant to use spray foam and others are encouraging them, telling them that it's extremely rare to have the kind of problem you have. But in fact, it does happen, if only very rarely, and when it does, it's a miserable mess with no good solution, as you are experiencing. So I've thought about what I would need to feel comfortable proceeding with spray foam in my own house, and what I'd need is a contract that clearly specified that the remedy would be for the contractor (or their insurance) to buy my house at fair market value and pay for my moving costs. Of course, your contract doesn't say that, but it might be useful reference point for conveying what scale of effort might be needed to remedy this.

        To clarify, I've never had spray foam done in my house.

        1. Expert Member
          MALCOLM TAYLOR | | #4


          I think you are spot on. Spray foam problems are rare, but when they do occur an be irremediable. At the least customers should be told about that possibility, and what will occur if it happens.

        2. acama23 | | #5

          Again, I appreciate your response.

          I have seen those discussion here and there as well. It is not encouraging to say the least. I would like to say that I believe were are in a rare / extraordinary case here. The contractor says he has never experienced an issue like this in 10-12 years but I'm not so sure.

          The manufacturer is involved and has even taken a few bulk samples to be analyzed. When I pressed the contractor on what the manufacturer recommends for removal he says that they're a large company and don't really make those types of recommendations.

          So basically, flying blind from a contractor perspective of remediation as well as the manufacturer. Truly uncharted territory from my vantage point.

          There has to be others out there that have gone through this. Do you recommend any channels to reach those people?

          I plan on speaking with legal counsel to get their opinion as well as if they have dealt with this in the past and can provide some context in that regard.

          Thank you for your time.

  2. charlie_sullivan | | #6

    Just giving this discussion a bump in hopes others will chime in.

  3. StephenSheehy | | #7

    As a retired lawyer, I agree with Charlie that you should consult one. Get someone with some experience in construction law. This is the kind of case I'd have been glad to take on a contingent fee basis, i.e. no fee unless you win. But don't look for some guy who advertises on TV.

    1. acama23 | | #8

      Thanks for your advice. I’m speaking with a recommended attorney as a consult. They came recommended based on our environmental services company that deals with spray foam install issues.

      Also following through on homeowners to work that channel as well. I appreciate your thoughts on the matter

      1. Expert Member
        BILL WICHERS | | #9

        If the enviornmental company is reliable, then the lawyer(s) they recommend probably will be too, as they've probably worked together before. There is pretty much zero chance you'll get anyone's insurance to buy you a new house, but insurance will typically pay for remediation work. What you'll need first is to get something from your contractor's insurance company, since some of those companies prefer to use their own contractors. The remediation itself will likely be similar to what is done for mold, which is a physical removal of the problematic material (typically manually, and then sand or media blasting to get the last of it). This is a messy process, but they'll usually enclose the work area and run ventilation similar to what is done for asbestos abatement projects. If the work is over a large portion of your home, you'll probably not want to stay there while the work is being done, and that work is likely to take a few weeks to complete.

        One issue I can see here is if the problematic material (and I'm assuming a bad spray foam mix here) may have soaked into some of the wood framing in the home, which will complicate removal. It may be possible to replace some of those areas of framing, but another option would be to encapsulate the trouble spots. you could potentially use closed cell spray foam (I've never tried that), but I don't know if that will be reliable in this case. There are primers that are known to seal up stinky stuff (nicotine, cat pee, etc.), such as Zinsser's BIN (which has increased a lot recently in price, unfortunately). You could use a few coats of BIN to encapsulate the problem areas after physically removing the bad spray foam, then insulate normally in those areas.

        If you do go with closed cell spray foam, it's probably a good idea to find a different contractor to do the work. Bad installations tend to be due to inexperienced crews, which would make me question the ability of that contractor to do a proper installation over previous bad installations.


        1. acama23 | | #10


          Thank you for your reply. I submitted a claim to our homeowners today so that they can go after the contractors insurance. I'm hoping it will provide some short-term financial assistance so that we can find housing and the like.

          I was told (just last night) but an architect friend that yeah, remediation will be similar to mold abatement. They will have to remove what they can, demo in areas where the foam is inaccessible (which are on the finished portion of our third floor) and completely remove what they can. This will be done with sealing off any of the living spaces below as best as possible and running ventilation (hopefully with filtration for any dust particles). I was told my architect friend uses Belfor for their remediation stuff when it comes to smoke damage.

          The soaking into the wood portion you mention is what worries me long-term. I told the SPF contractor this and they laughed and thought it was the most ridiculous thing I've ever said. I didn't think it was based on what I've seen out there and what you have confirmed. It is a real concern.

          The architect friend said a heavy duty primer would be good as "sealing off" any future off-gassing. I'm glad you're recommending the same thing and providing that guidance to others.

          As far as encapsulating with more foam? No chance. I've soured on the idea of foam in the house. The remaining close-cell will have to have a thermal barrier put on it I'm told. I'm not sure why the contractor neglected to do this or mention it.

          This is an ongoing nightmare for us but I'm so thankful for everyone providing their input. Thank you again.

          1. Expert Member
            BILL WICHERS | | #12

            Belfor has been a customer of mine in the past, and I always liked working with them. They are good people to work with.

            The "soaking in" part sounds funny if you only consider CURED spray foam, but improperly cured material still has some of the liquid precursor chemicals present, and that's the stuff that could potentially "soak in" a little. I doubt you'd get really deep penetration, since the stuff is pretty thick, but I think it would be able to get in enough that simple surface cleaning wouldn't be sufficient to fully remove it. I would be especially careful with any end grain (the ends of boards), since end grain is more prone to "sucking up" stuff compared to the sides of a board.

            You'll want a shellac based primer, which means the original BIN. That's the best thing when you're trying to seal up something nasty. The stuff stinks though, so you won't want to be around for a few days after that stuff is applied. Once it's dry though, it's fine.

            I myself have never seen a bad spray foam installation, but such problems most certainly can and do happen on ocassion. I think the best way to avoid problems is to ensure you have an expierenced crew doing the installation work, and make sure the installation is done during weather that won't cause problems for the material (not too cold or hot, and not too wet). My concern is always to make sure people don't get an overly inflated view of the likelihood of problems, but it's also important for people to be aware that problems can and do sometimes occur.


  4. Expert Member
    Michael Maines | | #11

    I'm glad you're going with legal counsel. I'm often dismayed by our sue-happy culture but this is the kind of situation where it's your best path forward. As you and others have said, these kinds of problems are rare but they do happen. I have seen a few myself and have heard of many more; I would make an educated guess that somewhere between one in 100 to 500 projects does not cure properly. Those are pretty good odds, but if you're the unlucky one, as you have found, the penalty is high.

    The idea that uncured liquid resin could soak into framing is perfectly logical. Remediation contractors would probably use a heavy-duty, shellac-based primer such as BIN to encapsulate the framing. If it works on cigarette smoke I imagine it would work on resin odors.

    1. acama23 | | #13

      Thank you for your response. I do believe this to be a rare issue. I don't want to fall into the "sue right away" mentality. I really have tried to reserve that as a last route. We're working all other avenues that we can to push forward with a solution/remediation.

      Thank you for the comments on the shellac-based primer. That sounds like the best way to "seal" things up once fully removed.

      The contractor and the environmental services group talked. They want to run filtration (new air in and old air out) for a few days. The contractor said that they didn't run much during the install. This statement from the contractor is a definite red-flag to me. There should be a negative pressure environment during install. Right?

      Anyways. They want to run filtration and HEPA vacuum and little debris in the area. After this they want to run indoor air quality tests again.

      I'm on the fence about this. I honestly want it removed. If it has been this long, and everyone agrees it is a problem I just want it out altogether.

      I don't believe filtration / air replacement will completely fix the problem. I just don't want to get into a situation where the air quality tests are lowered but the odor is more faint meaning it is still there and we'll battle down the road over liability and remediation all over again.

      Thank you for your (and everyone else's time).

      1. Expert Member
        BILL WICHERS | | #14

        Spray foam isn't normally installed in a contained area under negative pressure. Spray foam installation isn't considered that hazardous, so it's just done in open air, with a recommendation that other personnel not be on site if they don't need to be. In practice, this typically means only the spray foam crew is on site during the installation.

        I don't think HEPA filtration is going to help you much with solvent vapor issues. I would rather see outside air filtration, with cross flow. This means "air comes in on one end and goes out the other". The usual way to do this is to run negative pressure in the problem area, with the blower exhausting to the outdoors through a nearby window or door. Have a window or door on the OPPOSITE END of the problem area also open for air to come in. Run this way for 2-3 days. Things will probably seem lots better, but don't immediately think it's solved. Wait another 2-3 days WITHOUT ventillation to see if the problem returns. If the problem returns, and to similar levels as it was before the venting, then you really do have a problem, and removal is probably your only real option. It's important to wait a while after venting before testing again though, since venting will artificially lower any concentrations of "problem stuff" in the near term, you want to make sure the actual problem is solved permanently.

        There isn't any need for HEPA filtration here if you run crossflow with outside air as I described, so they can use the same blower box without a filter in it. I wouldn't let them set things up in a recirculating setup (filter only with no outside air venting), since that is unlikely to do anything in your situation.

        BTW, I would let them run the ventilation test that they want to run. If it doesn't help, that will give you more leverage with the insurance claim: "we already tried the easy stuff, it didn't work, removal is the only option, pay up Mr. Insurance Adjuster" ...


        1. acama23 | | #17


          Thank you. Thanks for correcting me on the negative pressure comment. I think that makes a lot more sense given that it usually isn't a problem.

          The cross-flow was recommended; 2-3 days sounds reasonable. I did ask how long to wait after and you answered that as well. I appreciate you providing the timeline for both of those things.

          On your last comment. The ventilation tests. Do you mean the cross-flow or the indoor air quality test thereafter? I don't really want them setting up fans or at all really. The mechanical ventilation they did setup (by the operations manager) was done so incorrectly as per the owner of the company. It didn't give me any confidence in their abilities.


          1. Expert Member
            BILL WICHERS | | #20

            You want to have the do things in this order:
            Setup for cross flow.
            Wait for 2-3 days (more is better) for the system to "air things out"
            Take down the ventilation system, close things back up (close windows or doors that were opened for ventilation)
            Wait for 2-3 days (more is better) for the system to restabilize, and to "stink back up" if the problem is something deeper.
            Run any air quality tests.

            If you have doubts about the contractor, request that the enviornmental company advise them on setting up the ventilation system. It's really not that difficult to do, you just want air to MOVE THROUGH the problem area, so that there is a constant flow of fresh air from outdoors moving through the problem area to carry away any contaminants.

            The important thing is to wait a while before testing after the ventilation stops. It takes a while for any offgassing problem material to "stink things up" again after a big airing out, and you want to make sure that the problem -- the "stinking up" -- is solved. You don't just want a band aide. Think of the difference between scheduled dialysis treatments instead of a kidney transplant. You want the permanent fix, the kidney transplant.

            I would recommend running the ventilation test. I think if you don't at least try that, the insurance company is likely to push back on your claim, thinking that ventilation alone might solve the problem. If you've already tried it, and it didn't work, then there is no argument to be made that maybe ventilation alone is all that the insurance company needs to pay to have done.


      2. Expert Member
        Michael Maines | | #15

        Coincidentally, last week's BS+Beer Show was about spray foam--you might find it worth watching:

        Best practice is to run cross-flow ventilation for 72 hours after installation, to clear both the aerosolized particles and any off-gassing chemicals. I've never had an installer recommend that, but they sometimes recommend leaving windows open for 12-24 hours. Like Bill, I don't see a downside to letting them try ventilation as a solution, but if they test immediately after ventilation it won't tell you anything--you would want to wait a few days for the space to return to stasis first.

        1. acama23 | | #19

          Thank you. I'll watch later this evening. Much appreciated.

  5. user-5946022 | | #16

    As one additional data point, I had open cell foam installed in two main locations in an under construction home. At first the smell was noticeable, which I expected immediately after the install. The smell somewhat dissipated, but would come back particularly strong when it was humid outside in one of the two areas. A few months after install, prior to occupancy, when there were still days I could smell it, I decided to embark on an "airing out" program - open all the window to try to dissipate the smell. That helped, but the smell would come back when it go humid; it was just a bit less every time, evaluated by the fact that at first the smell was easily detectable further from the sprayed area, and as time went on, detectable only closer to the sprayed area. I ended up airing out the area at high humidity times for 3 years. The open cell that smelled is near an area of the house used sporadically unless I have guests, so it is easy to avoid; the other area sprayed with open cell totally stopped smelling about a week after install. After the 3rd year, the smell from the smelly area stopped. I don't know if it just took that long to fully cure or what, but I definitely don't have the smell anymore. I'm sharing this to let you know that high humidity, in my case, seemed to bring the smell back, but that eventually it does go away totally. I presume air movement helps, and that more air movement helps more, so the fans should help.

    1. acama23 | | #18

      Thanks for the reply. I'm glad your smell did eventually go away.

      Due to some health concerns and that we have two kids in the house and want to use that part of the house, etc. I'm unwilling to live like that knowing it may be an issue.

      Again, I thank you for your information on the topic and you providing your story.

  6. acama23 | | #21

    Just a quick update on the situation.

    The contractor agreed to remove all the open cell that they could access. They did a fairly good job at it and were very clean. They had one fan sucking air out of our attic and another bringing air in.

    They encapsulated the areas where they removed the open-cell with closed cell foam.

    This was two days ago on Tuesday. I just went up there today and shut down the fans (they were very loud and the neighbors were starting to inquire about the sound). I'm going to let the house air out today since it is going to be a little warmer.

    I do have some initial concerns though. I stuck my head in a collar tie space (little area that they managed to rip out and respray) and it still smells a little. I know it is maybe a little too early to come to a conclusion but for me to smell it that quickly wasn't what I had hoped for.
    I'm a bit deflated thinking that the smell will just keep coming back.  This is exhausting and any thoughts on the matter are helpful.

    1. Sblover | | #22


      Same situation here. Happened last summer and we were out of house for six months in what can only be described as a nightmare. Unfortunately, we had to pay for remediation and are out a few hundred thousand so far. Manufacturer was a large publicly traded company who threw us to the wolves - even knowing we had a baby.

      Couple thoughts:
      -your house is a toxic waste site. Treat it as such.
      - yes, it soaks in. A lot. Like it’s insane and I would never have believed it by reading some post. Only by living it was I convinced.
      - coatings might help some, but not all.
      -we removed sheathing and scraped, dry ice blasted and coated all remaining wood.
      -I have had exhaust fan running for 9 months now. The exhaust is till toxic enough to make the side of my house smell extremely strong (exhaust is out of gable wall).
      -spending a few hundred hours air sealing the attic from house is what finally let us move back in. I’m not exaggerating the time required.

      What’s the solution? Unfortunately, I’m not sure there really is one.

      1. acama23 | | #23

        Wow. I'm so sorry this happened to you. I can fully understand the nightmare and feel exhausted since we're just at the beginning.

        I'd like to chat more about your situation, the product, the timeline, remediation, etc.

        Is there a way you can contact me directly? My email is [email protected]. I made a throw away email address so that I can turn it off if spam starts coming. But rest assured that goes to my personal email. I'd like to chat over the phone but only if you are willing.

        If you can find it in your heart to reach out and share what you went through and everything it would be a huge kick-start. Our family is unsure where to go from here.

      2. allison2023 | | #28

        What type of insulation did you put in after you had the spray foam removed? We have open cell in our attic that needs to come out.. we need to figure out how to insulate the conditioned attic after removing the foam. Thanks!

        PS- wondering if we should move forward with the attic sealing now?

      3. HFSP | | #30

        Do you know the foam manufacter that was installed? I am having the same issue and everyone denies wrongdoing. Is there anyone that can help?

  7. acama23 | | #24

    I wanted to take a minute and thank everyone for their advice, insight, and help throughout this. It is disappointing that so many people have known or experienced this issue. It is truly light-changing and tragic. Our family has been through a lot and we're just getting started.

    I would like to hear from anyone else impacted by this. If you want to share your story, or the story of others, please contact me @ [email protected].

    I suspect that 1,2 people in this thread experiencing this aren't alone and therefore shouldn't be when their lives get completely upended due to spray foam insulation.

  8. acama23 | | #25

    Had the air retested after ripping out open cell and encapsulating with closed cell.

    We had cross flow setup for 3 days, then I shut up the house for 3 days.

    An air test after this was performed. Air quality test (TO-15) samples indicated lower tVOCs but higher 1,4 Dioxane than last time and the presence of 1,2 Dichloropropane which was not previously detected.

    The smell is very much still there.

    I’d also like to thank a few people for contacting me. It is difficult to hear such terrible stories of families being displaced by poor SPF installations.

    It is important to keep talking and to seek answers. Again, I encourage everyone to reach out if they can.

  9. nynick | | #26

    Pardon me if you have already mentioned this, but where are you located?

    1. acama23 | | #27

      I'm in the greater Philadelphia area.

      1. HFSP | | #29

        Can you please contact me? I am having the same issue you did. Do you know the foam manufactory company and who did you get to perform the testing?

  10. jpcase | | #31

    I've been displaced from my home due to SPF. Foam clearly didn't cure. It has been "removed" though independent consultant was over to house and showed how the contractor didn't do a complete removal as sticky stuff and material (that I now understand would not have become inert) remains on framework.....and possibly absorbed by old batts they failed to remove before installing the SPF. "Sweet" chem-y smell remains in house and the consultanys believe it's from polyols that remain from foam. Cannot be aired out after many attempts, others have noticed the smell too. Handheld IAQ meter did not detect significant levels of VOCs but IAQ specialist told me I'm not crazy, the smell is indeed there. It's triggered health issues that drove me out of the house. Am looking into remediation but I'm now wondering if it's possible for the fumes of uncured foam to absorbed by painted sheetrock walls and remain in the air of the living spaces that way. Does anybody know about this? Thank you.

    1. freyr_design | | #32

      This certainly happens with fire damage and wood so I would not be surprised if many of the building materials in your house could have absorbed the smells.

      I have no idea if it would help in your situation but often times ozone is used to oxidize chemicals which in turn reduces the smell. Might be worth a shot but I would certainly research a bit more.

      1. jpcase | | #33

        Thank you. Ozone was tried for 12 hours but results were temporary, smell back in full force the next day. Also tried air purifiers, which just seemed to spread the odor more strongly.

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