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Community and Q&A

Odor problem in attic after spray foam applied

GBA Editor | Posted in Green Products and Materials on


I am looking for any advice or suggestions with regards to a situation we are now dealing with in my home after changing our vented attic to a non-vented attic or semi-conditioned space.

Let me provide some background information. About 3 months ago an insulation company used the Demilec Sealection 500 product and sprayed our entire attic space below the roof. Prior to this we did not have any smell in this attic besides a typical attic smell that was likely not venting properly. The spraying was completed over a 2 day period while the temperature outside was around 90 degrees. The home is located in the Northeast. The attic is only accessible through pull down stairs from the ceiling. Following the spraying the only ventilation that took place was to keep all of the windows open on the bedroom level below with various fans running in some windows. This took place for several days to continue to try and ventilate the space. After a week or longer there continued to be a strong chemical odor that was coming through HVAC ducts as well as through recessed lighting and bathroom ventilation fans. The insulation company came back and said they had spoke with the manufacturer and it was possible that the fiberglass insulation that remained on the floor would need to be removed because it could be holding onto the odor from the spraying. There seemed to be some improvement following that removal, but the overall smell has continued to remain since that time. The odor drops through recessed lighting and bathroom fans and is stronger in certain areas of the bedroom level.

They came back again and hooked up a special ventilation fan to our attic door and have vented out the attic for 4 days. The odor continues to exist. Demilec is now sending a representative to come and take samples of the air and foam. Our concern is that we are potentially breathing in toxic air or something else is reacting in the attic space. We will wait and see what the results are from Demilec. We just are not sure what to do if they say everything is fine or if they say there are problems.

Does anyone have any experience dealing with this? Are there any known solutions? Has anyone been involved in a situation where the spray foam has to be removed? Can it be removed? Any help or advice would be appreciated. Thank you

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  1. GBA Editor
    Martin Holladay | | #1

    Thanks very much for your post. It is one of four or five recent reports we have received about spray-foam jobs gone wrong; usually the first sign of a significant problem is a bad odor. We need to hear these stories. The evidence is accumulating that mixing problems by spray foam contractors can cause nightmares for a few unlucky homeowners.

  2. Danny Kelly | | #2

    We had a similar issue with spray foam but instead of an odor being trapped it was moisture. I think part of the problem in a retrofit application is the attic area is truly unvented and not actively conditioned. Seems the theory on this is it relies on leaks in the HVAC system and ceiling and that area is passively conditioned. The fact that you do not get a true air exchange or any fresh air brought will increase the amount of time it would take to passively exchange the air. I think if you have plaster in lieu of Sheetrock it makes the problem a little worse – I think that was one of the contributing factors in our case. We had to mechanically remove the excessive moisture in the attic and once we got it down, the attic performed the way it was supposed to.

    According to the manufacturers, all “off-gassing” etc. should occur in the first 24 hours so the product should not be releasing any new odors, these are likely remaining from the installation if in fact the information from the manufacturers is true. I think running a fan from the attic and vent it out a window to completely remove the attic air to completely change out the air is the way to go. Sounds like that may be what you are doing now. Even a small fan would exchange the air a short amount of time so a few days should be plenty I would think.

    I would also do some good air sealing at your ceiling level and duct sealing on your duct work. Many will tell you that these measures are not necessary since you have moved the thermal boundary from your ceiling to your roof line. I think from an energy saving perspective, this may be true to a certain extent but from a comfort and performance point of view, these measures will ensure your system is working the way it was designed. The attic is only semi-conditioned even though this is typically referred to as a conditioned attic. There will still be a temperature differential between living area and attic so I think it makes sense to avoid communication between these two areas as much as possible.

    I have never had to remove foam but do know that it can be done and would assume this would be an expensive process that you can hopefully avoid (I think JLC just had an article on this). Two other ideas you may be able to consider especially if the product is continuing to give off an odor. Install a continuous running exhaust fan in your attic vented to the exterior. This will remove the stale air in the attic and put a slight negative pressure on the attic space and will bring in conditioned air from below thus avoiding having the odor come down into your living area. One other idea is to try to encapsulate the foam somehow, maybe installing a product like thermoply or thermax and sealing all the joints.

    Good luck and let us know how it goes.

  3. Dave | | #3

    Thank you for your quick replies. I will certainly keep this thread updated as we determine how we will proceed. One of the first suggestions from the insulation company was to seal all of our recessed lighting and other fans to prevent the flow of air through these openings. However, we want to know what is causing the odor first and why. When our thermostats are calling for air the returns are pulling the air quicker through these openings in the ceiling as the pressure changes and dropping the smell to our living space. We hope to figure something out soon as it has been a complete nightmare. Thanks for your ideas.

  4. Read | | #4

    I am experiencing the same problem with Demilec spray foam; we lived with the troubles for 45 days while we were ventilating the attic through the gables. We have recently had the foam removed and an attic fan installed. However, we are still experiencing issues, probably the same as you, since the particles are pulled through openings from the attic into the living quarters. I was hoping that having a breathing attic again would cease our problems, but it has not entirely.
    Please continue to update this forum on your proceedings.

  5. Dave | | #5


    Thanks for your response. How difficult was it to have the foam removed? Did Demilec ever come in and test your foam and air quality? Is there any explanation why your space still has an odor after having the foam removed? I am still waiting for Demilec to come into my home which will hopefully be soon!


  6. Brian | | #6

    I have the exact same odor problem after having Demilec Sealection 500 sprayed to create a sealed attic. I've been living with it for about a year and a half. It's actually gotten worse over time, and is especially bad during hot days. It also has caused health problems for all of my family. Demilec has been out to my house twice to attempt to fix the problem. Thus far, nothing has worked. I've recently installed a dedicated ventilation system in the attic that keeps most of the chemical laden air out of the house. It's an improvement, but this situation is far less than ideal. I'm currently considering my next moves (legal action, sell house, remove foam). I really wish there was someone to turn to for advice in this situation, but thus far I've found no one.

  7. Phil_in_FL | | #7


    I have a similar issue. is it possible your consideration of it getting worse is caused by
    1) increased sensitivity due to prolonged exposure
    2) increased off-gassing due to the fact we are in the summer now?

    Does your ventilation in the attic draw air out of the attic and to the outside, inject fresh air into your hvac supply, or both? How long has it been running?

  8. Dave | | #8

    Thank you all for your responses. I hope to have a Demilec technical representative in my home sometime over the next week or two and will update the thread. There is no doubt that when it is very hot and the sun is baking down on the roof that the smell is much more intense. Paul, Brian, Phil or others with this issue are welcome to email me at [email protected] if you wish to communicate further about the problem and solutions to fix this awful situation.

  9. Phil_in_FL | | #9


    4 Days of ventilation would likely have been sufficient if it was done when it was fresh. Now the vapor is trapped in the wood in your attic, and it must be ventilated for a few months to correct this. Keep ventilating...


  10. wjrobinson | | #10

    I have had one home sprayed with unvented roof style sprayed roof deck. New construction with Icynene open cell. I was in building while being sprayed, slight chemical smell. Then we had the building I guess luckily very open for weeks after and prior to drywall going up.

    There is no chemical smell now and there was none after drwall up and painted.

    Sounds like doing an existing home that is lived in is almost not to be done.

  11. Brian | | #11

    Phil -
    I definitely think it is worse because of both of the reasons you cite. Summer makes it worse and the prolonged exposure has made us much more sensitive.

    Regarding the ventilation system, I actually have two. I have an ERV that changes the air in the home with outside air. I also have a dedicated vent system that draws air out of the attic and vents to the outside. The problem with the attic vent is that it raises the humidity in the attic when it is running. I've been using a dehumidifier in conjunction to offset. It's only been running about a week at this point, but it does seem to be helping.

    Demilec was out to the house again today. They took a bunch of samples and are supposed to be getting back to me with next steps.

  12. Phil_in_FL | | #12


    Did they pay for any of the air exchangers?

    Is there a specific problem with raising the attic humidity?

    Higher humidity should raise the rate of off-gassing, and as long as you are ventilating, that is a good thing.

  13. Don | | #13


    Application of these types of products release chemical vapors during application and curing. I think the application in finished homes may be of more significant concern than while the home is initially being constructed (open air). The main chemicals of concern would be Tertiary Amines and Diisocyanate(s). High concentration exposure can lead to hypersensitivity (i.e. during periods of application and possibly 24-48 hours following). Once sensitized, symptoms can occur even when exposure is at low / trace concentrations following the initial exposure. Air testing may not provide accurate data after the curing process and may not be sensitive enough to detect low level concentrations. Heat and humidity will cause the product to release odors and possibly low level concentrations below the Limit of Detection (LOD) for most sampling methods. Once sensitized, a person can have reactions at even trace concentrations. In the event the home is mechanically ventilated (i.e. central air) the air is generally recirculated through the home with little fresh air infiltration for dilution of any contaminants or residual contaminate that might be present or regenerated by product off-gasing, not to mention (attic air entrainments) if there are ductwork leaks in the ducts running through the attic space (which is now unvented). The evaluation process can be complicated. There is much more to consider and evaluation / study can be expensive. Ensure that the person(s) doing the evaluation(s) is competent and certified in Industrial Hygiene with experience in these types of assessments. In addition, it is advised that a Medical Professional specializing in Occupational Medicine (familiar with Amine and Diisocyanate exposure) be consulted. I hope this helps.

  14. Brian | | #14

    They've not paid for anything. The installation contractor has run away and his phones no longer work, and Demilec has verbally suggested they will do lots of things, but none of those have become real. I certainly believe at this point that my family falls into the sensitized category, as we detect smells when others don't. I'm in the process of engaging an industrial hygenist to validate what we already expect. I have searched for a medical professional to help, but none that I've found are familiar. They just want to put us on asthma medicine. At this point, I'm starting to think that my only option is to find someone to remove the foam, which I am dreading. It's going to be expensive and annoying, not to mention the inevitable collateral damage that will occur. After that, it's probably a legal issue.

  15. Phil_in_FL | | #15


    If you go outside of your home for a couple of days, do your symptoms totally go away, and, with the constant ventilation of both exhaust from the attic, and fresh air into your HVAC system, after returning after a couple of days, do you have an acute onset of symptoms again?

    Can you still smell the chemicals in the house? (not the attic - I assume that the smell is obvious there even with the ventilation)

    Removing the foam will certainly cause other issues. Specifically - polyurethane dust, and you will have to replace it with something, all of which has chemicals as well, eg Fiberglass has formaldehyde in it, cellulose has fire retardants in it, etc.

    I know in my case, the symptoms that my family has had have been minimized since we began ventilating the attic to the outside, and at this point I believe it is likely that after a couple of months of ventilation, we will probably be able to stop ventilating and maintain a low concentration of vapor in the house air.

    In addition to venting the attic, I also found this study:

    And I have put 15 plants around my 3200 sqft house (less than the 1 plant / 100 sqft recommended by NASA, I may put a few more around, but I want to make sure we are able to care for this many plants before adding more to potentially kill, and there also seems to be a functional limit to how many plants can reasonably be placed around the house.

    That said, I think the plants have also made a very noticeable improvement in the indoor air quality, separate from what the venting has done -- and in some ways the air is probably better than it was before the foam was installed in the first place. Everything synthetic in your house off-gasses, paint, furniture, hardwood floors, tile sealer, foam mattresses, etc... Additionally, Humans and pets convert Oxygen to CO2, and other than whatever leakage you have to the outside environment, there is no conversion back to Oxygen without plants. If you have Plants, they will absorb toxic VOCs as food, and also convert CO2 to O2.

  16. Phil_in_FL | | #16

    I'll also add, I don't mean to imply that the foam itself is not off-gassing, if you say it is, it probably is.

    That said, even if the foam wasn't off-gassing, it made your home much more airtight, and therefore increase concentrations of whatever VOCs the rest of the stuff in your house was off-gassing, since there is now less outside air making it into your house. Even with your forced air exchangers, it's probably still much less air exchanged than there was before.

  17. Riversong | | #17

    "Removing the foam will certainly cause other issues. Specifically - polyurethane dust, and you will have to replace it with something, all of which has chemicals as well, eg Fiberglass has formaldehyde in it, cellulose has fire retardants in it, etc."

    Yes, but removing the source of the problem is going to be the only potentially definitive solution. I would recommend insisting that Demilec pay for all removal and associated costs under threat of suing them for lifetime health costs and considerable adverse publicity. And then seal your ceiling and ductwork, insulate the attic floor with cellulose (borate fire retardants are natural and non-toxic), and ventilate your attic.

    But the take-home lesson for you and the many others who believe that foam is the answer to energy conservation is this: every artificial chemical has adverse effects on living things and the ecology of the earth.

    While the statement above - that everything has chemicals - is simplistically true, the earth is composed of natural chemicals with which life has evolved and we have introduced 80,000 new chemicals (250 million tons per year) that never before existed on earth. One doesn't need to believe in God or Sara Palin to realize that a profound Intelligence guided the evolution of a living planet that has remained in a delicate homeostasis for 3.5 billion years, and in a mere couple of hundred years humanity's limited intelligence (and more limited wisdom) has nearly destroyed this work of cosmic art.

    Using natural detoxifiers, like plants, is a reasonable mitigation strategy. But eliminating or encapsulating the source (as well as any other artificial building materials) is going to be the only remediation - and that may fail if the gases are absorbed in the framing and your family has reached a threshold level of sensitization (which may cause secondary sensitivity to other substances). You may have to move to a healthier house.

    It's past time that we stop pretending we know better than Mother Nature and that we can create technological "solutions" to the unintended consequences of our previous technological "solutions".

  18. Phil_in_FL | | #18


    I'd agree that I probably wouldn't recommend someone to install this product in their homes after my own experience with the fumes. Personally, though, I think the performance of the product is unquestionably superlative, the removal is sufficiently complex, and as long as I am able to mitigate the problem, I do not plan on removing it.

    If I could go back in time, I would not have gone with foam, however.

  19. Riversong | | #19

    " I think the performance of the product is unquestionably superlative"

    But this is just the kind of narrow perspective that got you and many others in trouble.

    If an insulation material is expected to perform only as an air seal and thermal barrier, then it's fair to say that the performance of Demilec is adequate (superlative would be a gross exaggeration, since it's R-value is no more than dense-pack cellulose).

    But an insulation material, for green design, should also:
    - have a very low embodied energy
    - have very low carbon contribution
    - be recycled or recyclable (and ideally compostable)
    - be installable without excessively specialized equipment and with an achievable level of training
    - be easily removable for renovations and repairs
    - contribute to envelope moisture buffering and not retain moisture in the event of leakage or condensation
    - be sufficiently vapor open to allow building materials to dry out in the event of leakage or condensation
    - be non-toxic in manufacture
    - contribute no toxic chemicals to the living space (and ideally help maintain a high negative ion concentration)

    By these standards, no foam insulation has better than poor-to-failing performance. To build truly "green" or healthy and sustainable requires a far broader perspective than is generally found in the so-called "green" building movement.

  20. Dave | | #20


    I think you make some excellent points and thanks for your advice. You suggest that the definitive solution might be to remove all of the foam, but others have suggested that even after doing this labor intensive work that the odor still exists to an extent. I would think it is almost impossible to remove every last bit of this foam as it is stuck to the roof deck. Would this indicate that maybe besides there being a problem with the foam that the vapors from the original installation are all over the wood in the attic and are reacting still? I know different fiberglass installation can absorb the vapors and cause odor issues if left behind on the floor, but what about the actual wood? I think this is something that Demilec has recently started discussing amongst themselves. I also keep wondering what my options are if Demilec comes back and says the foam ratio tested fine and the air quality is fine despite the fact that the odor exists still and is causing the same problems.

  21. Riversong | | #21


    If Demilec tries to duck their liability, you'll need a doctor familiar with chemical sensitivity, an industrial hygienist to test the house, and a good tort lawyer. You'll have to decide whether it's worth the effort. Threatening Demilec with adverse publicity might goad them to action.

    You could choose to encapsulate the foam, though I don't know what an appropriate product for that would be, or remove the foam and seal the wood framing and sheathing with a pigmented shellac (like alcohol-based BIN). Certainly remove any fiberglass, since that's nearly worthless anyway and replace with cellulose. And vent the attic, ideally with continuous soffit and ridge vents.

  22. Phil_in_FL | | #22


    I don't disagree with any of what you are saying about the problems with Foam -- but since it is already installed, you aren't going to undo the carbon usage, the embodied energy, the non-recycled materials, etc... It's already there -- and *if* it can be mediated, there's less impact to that as compared to ripping it out and installing something else.

    If it can't, then that's another story.

    Like I said, I don't recommend others install this product.

  23. Phil_in_FL | | #23

    Just giving an update here .... Demliec has supplied a powerful confined space blower which I've attached to the ductwork I ran myself from the attic to the outside to try and resolve the issue. The problem is certainly getting better now. I'm not sure what the timeline will be until this is resolved, and the constant ventilation does make the energy load for cooling the house much higher, defeating the purpose of the insulation in the first place -- but hopefully soon the problem will be fully resolved and the fans will no longer need to run.

  24. Phil_in_FL | | #24

    It looks like the blower was not a good idea as it added to the humidity /moisture in the attic space, which, as an IAQ expert pointed out was actually increasing the problem, not making it better. I'm now in the process of trying to install a ERV, and properly sealing the attic off to keep the humidity in the entire house, including the attic, low at all times, and having a high rate of air exchange at the same time.

  25. Danny Kelly | | #25

    Hi Phil - A few thoughts/questions:
    Is your odor gone and you now have a humidity/moisture problem?

    Where do you think the moisture is coming from? House, Crawl space, exterior, trapped in the attic? We had a similar problem on a retrofit and I think our problem was moisture trapped in the attic. I would recommend measuring and tracking the temp and humidity in the attic, house, crawl and exterior and maybe you can figure out exactly what is going on. Can take a few readings a day or better yet purchase a few dataloggers. I assume your "blower" was an exhaust - from attic to exterior?

    How do you plan to install the ERV? Is it part of your HVAC system or a stand alone system. If you are thinking a stand alone system and are installing it in the attic, I'm not sure that is going to do you much good. How will you determine when to turn it on? If conditions are worse outside than they are in the attic, you could be bringing in more humid air - the ERV only slightly tempers the air and I would think there are certain times that it will not perform properly for you. Sounds like an expensive fix that may not work.

    Why do you want "a high rate of air exchange"? Isn't that the purpose of the foam - to lower your air exchange?

    I'm not sure I completely understand all of your problem but allow me to make a low cost suggestion. This option assumes that the air in your home is conditioned and low humidity. Rather than installing an expensive ERV with a high CFM, install a low cost bath fan like 80CFM and install it on a humidistat (or thermostat, or run continously depending on what your issue is). Install a small 4" duct from your conditioned part of your house to the attic with a butterfly damper. When the humidity gets high, the fan will turn on and pull conditioned air from the home into the attic and the humid air will get exhausted out (just like a bath fan). Although you will have a bit of an energy penalty for this, at 80 CFM, it should not be a huge deal and hopefully your attic will eventually get to an equlibrium with the house and will turn on very often.

    Thanks for the updates - please keep us in the loop. I have a feeling we are going to see a lot of problems like this - good to see how different people try to solve them.

  26. Dave | | #26


    Thanks for your updates. I think as we have discussed before humidity/moisture levels play a very large role in causing this odor. My home will soon be tested by an IAQ specialist and I am very interested in seeing the results. When I started this question in this forum back on July 11th the odor was very strong in my home. I continue to have the odor at different times but I have learned that it is always based on many factors including outside temperature, humidity levels, and other weather conditions. In addition the odor is forced down from my attic based on my thermostat schedule when I cool my second floor more in the evening. For me, it is most critical to understand the chemicals that now potentially exist in my living space, why they exist, what the odor causing agents are, and how to solve this problem going forward. Demilec has stepped in and has been very involved in wanting to figure out the problem for many reasons obviously. Unfortunately, the idea of tightening the home and lessening the air exchange sounded like a very nice idea for many reasons but in a retrofit installation it seems that it only causes many more problems. In our situation it was a Demilec Sealection 500 product that we are still not sure whether it was applied correctly but we will soon learn a lot more after the air quality testing has been completed. It would be nice to say that different HVAC solutions would correct everything, but why the ongoing odor issues, and does it make sense that trying to be more energy efficient should cause so many more problems? I go back to the original idea to let not only the home breathe properly but everyone living inside it!

  27. Eric | | #27

    I just discovered this thread. We had the same Demilec product installed in our existing home and there has been a lingering odor. My animals and myself have developed unexplained symptoms that I believe are related to the foam. What result did you get from the Demilec representative? Are there issues with diisocyanates?
    Thanks for any additional information.

  28. Dave | | #28

    Eric -

    Sorry to hear that you are experiencing problems following your foam installation. After speaking with others in similar situations over the past year it seems that the problem exists on varying levels. Some have had terrible symptoms following the installation while other like myself have luckily not experienced horrible problems as a result of the odors we have. Demilec does have an individual who is now responsible for dealing with situations such as yours to determine whether dangerous chemicals are being released from their product, or whether the product was improperly applied. They will typically send a representative to your home to review everything done. Call Demilec directly at their main office in Texas.

    In my own situation I was treated very well from Demilec and they visited my home several times to review the installation and they paid for extensive air quality testing from an independent IAQ expert near my home. Their number one goal is to prove that any odor or chemicals present are not coming from their product. They will often pay directly for any testing required since they are the big corporation involved and have to maintain a reputation etc. and obviously do not want to get sued. If they find a problem with their product then they will take responsibility for the situation and work with the installer to get it resolved.

    There were multiple problems as a result of creating a non vented attic space in my home. First, in addition to sealing my attic space I also had my unfinished basement air sealed with a different foam product that was used by the energy company contracted to perform the work. This company sub-contracted the Demilec install to a 3rd party who was authorized to perform the work. After extensive review of the attic by Demilec and the IAQ testing there were several findings. First, my attic was not completely sealed by the installer so there were several areas around my soffit that were continuing to allow air in to the attic space. Second, the IAQ testing revealed a combination of many chemicals in the air that were likely causing the odor now since my home was acting like a convection oven without any way to properly vent now. One of the more dangerous chemicals identified was actually off gassing from the foam that had been applied to my basement and was not actually coming from the Demilec product. That is not to say the Demilec foam was not releasing chemicals still, but not chemicals that were being identified in the IAQ testing location. It seems that other chemicals that previously had been able to vent were now just stuck in my home. I also do believe that the Demilec product should never be installed in a retrofit situation. I believe that this product was designed for new construction. The Demilec installer did not properly install the product and they never vented the attic properly during the installation which was caused many problems. Due to the volume sprayed in my attic it certainly caused an odor and my guess it will again when the weather is warm in my area. Humidity levels play a major role in odor as well.

    After several recommendations and lengthy discussions the original energy improvement contractor has agreed to try and resolve the situation. They will be installing an HRV in my home to bring in fresh air and expel old air. My home is on the border of being too tight so they believe changing the air with an HRV is the best way to try and remove old air and chemicals. The foam can only off gas for so long but be prepared for it to off gas for a lot longer than you were likely told. In addition after a period of time another IAQ expert will be brought in to determine whether the HRV is working and to identify if the chemicals still exist in the home. If not, then other ideas will be discussed. I will certainly update the thread with my results. Please feel free to ask any other questions that might be helpful to you.

    Lastly, I will say it has been a terrible experience and I would never have any foam product sprayed again in my home. I am sorry to hear you are experiencing problems.

  29. Ray | | #29


    I had this product installed in Nov in new construction. Needless to say we are still venting and falling behind on our schedule. The contractor who installed will not return calls nor confirm the exact chemicals applied to the structure.

    How were the test results.

  30. Anonymous | | #30

    Hello to everyone,

    Yes, we have joined this nightmare. We recently had Dylona install the Demilec foam and as you will see, here are the very same issues you are all dealing with. I was glad to find this web-site, because I have found there are no good places to turn with these issues. Therefore, the more this info gets out, well, buyer beware!

    DEMILEC PRODUCT Information

    12-27-10 DYLONA came and sucked out the insulation from the attic while wearing white suits.

    12-28-10 DYLONA came 7:00am, put on white suits and masks, began spraying
    FOAM by 8:00am. Around 9:30am we began to notice burning eyes, dizziness and burning throats along with a headache. Our son slept late that day and we got him up a little after 9:00am and asked him how he felt. Immediately he said, “I'm dizzy.” "Mom" and son left around 9:45am for the day. "Dad" stayed in the house ALL DAY. He felt dizzy and confused and had to go lay down outside several times. NO ONE TOLD US NOT TO BE IN THE HOUSE WHILE THEY WERE SPRAYING!
    Evening came and Mom and son came home and felt dizzy in the house, eyes and throat burning and headaches. Dad said he felt the same, plus had a cough. We had to stay at our friend's home for the night. COULDN'T STAY IN THE HOUSE.

    12-29-10 Had our friend's bring their MOTOR HOME over to our house and we parked it in the drive way. WE COULDN'T STAY IN THE HOUSE. We lived in the Motor Home for 12 days and 11 nights, then we moved back in and HAVE BEEN OPENING THE WINDOWS AND DOORS EVERY DAY WE CAN TO AIR OUT THE HOUSE.

    DURING THAT TIME, OUR SON WAS HAVING ASTHMA. It has been at least 4 years since he has had an asthma attach. Had to go to the DR. and got prescription for Albuteral and Pulmacort (which we didn't get because of cost) and had to use the nebulizer for over 15 days, and still using it as needed.

    We borrowed our friend's SHOP FAN and have been using it to blow the air out of the attic.

    1-24-11 WE ARE STILL AIRING OUT THE HOUSE AND USING THE SHOP FAN DAILY! The home, 28 days later, is still giving us allergy like symptoms. Itching eyes, stuffy nose and headache with occasional burning throat, dizziness along with muscle aches. Mike also has a chronic cough.

    1. Temperature when foam was sprayed was in the 30's.
    2. Mike took cut out of FOAM and product was varigated with veins of deeper yellow color.

    This is a copy of the letter we gave to Demilec. They are aware of everything as 1-24-11 a Demilec Rep. and the owner of the Dylona Co. came to our home. They spent 5hrs or so here at the house. The Demilec Rep. went right up to the attic and then, without, as much as a "hello" he went out on the front lawn and called his supervisor. He was talking a pretty long time. The advice was to ventilate. So, another fan has been put into the attic. The idea was to pull the air through and out. So, a soffit was punched out and that was the air access on the other side of the house. Over night, the smells came pouring through the house. We were coughing, achy and just couldn't stay in the house in the morning. We unplugged that other fan. Opening the windows again during the day. We live in FLorida and for now, we can open the house up during the day. (Not looking forward to the summer - with this) Turned the other fan around and we are sucking the air OUT both sides of the home. THE SMELL IS SOOOO STRONG STILL!
    I get the picture, there is no quick fix. We have to do something now, though, and probably will get the RV back again and cut down our orange trees and put it behind the fence. (Homeowners didn't like it in our driveway.)
    This is our situation NOW. The tech from Demilec is supposed to come this week and take a foam sample...... so the saga will drag on. We will update.

  31. 2tePuaao2B | | #31

    These are just examples of devestating problems associated with foam use that made it to this site.
    The problem is enormous and yet advise to use this toxic stuff remains at the top of the GBA suggestion list.
    How can that be Martin?
    Why is there only 1 responce from GBA that seems to make lite of the situation. "a few unlucky"??

  32. 2tePuaao2B | | #32

    A few unlucky?

  33. GBA Editor
    Martin Holladay | | #33

    I haven't seen this GBA suggestion list. What page is it on?

  34. Dave | | #34

    I think the bottom line here is that there is a very large disconnect between the manufacturer and the installers. The installers are not being properly trained or educated about the products they are installing. Demilec offers training to these installers but it is very difficult for them to monitor their installations unless a problem arises. The manufacturer is also not fully disclosing the composition of their products since some of it is a proprietary solution. So we don't really know what is in this chemical. Only after baking off the product in a laboratory do we start to learn about some of these chemicals that off gas for a long time. I absolutely believe the spray foam should never be used in a retrofit situation and especially never installed during extreme weather conditions. The product was not designed for this. It was designed for new construction as some of the reps will tell you off the record. There are too many variables when installing in a retrofit situation. Without proper ventilation during and after installation this will inevitably lead to odor problems, When the attic is sealed this will only create a much tighter home which now traps many of the new odors, and pre-existing odors that you never knew were present since they had been venting previously. Often times and HRV or ERV depending on your geographical location is essential to help bring in the fresh air and exhaust the stale air.

    The spray foam has certainly caused many serious problems for home owners, and the posts on this board only represent some of the bad experiences. I am sure it is much more common and there needs to be a lot more research and investigation into this industry and the affects of the chemicals in them. It would be great if this website were to provide further insight into these problems.

    My only suggestion to those who have a Demilec product installed is to try and work with Demilec and the installer closely until the issue can be resolved. It is extremely difficult to remove spray foam since it adheres to wood or other building materials so tightly. There will always be remnants leftover if it is scraped out. Also, insist that there be extensive air quality testing so you understand exactly what you are breathing. That is essential to fixing the problem and identifying where these chemicals and odors are originating from.

  35. wjrobinson | | #35

    Roy, posts of spray foam nightmares lead me to thinking it is real iffy to use. I must be lucky though that my contractor uses water blown Icynene which is the least scary foam most likely and he must really know how to spray it properly because we have had no problems. I was in the homes off and on all day every day that they sprayed, could barely smell the foam and never felt any other symptoms.

    But after many horror postings here, I too join with some and would say to never spray an attic with Demilec and I would never at this point use someone other than my contractor and I am now more aware of not spraying foam when the temperature is extreme. I also will always be onsite monitoring the work to make sure the foam is mixing perfectly.

    Every time a contractor is hired, they should be checked out. To me that means go to their sites and past customers. If this is not done out of convenience or saving time, then it is a gamble plain and simple.

    Let me ask you Roy, Where does GBA recommend sprayfoam retrofitting?

  36. wjrobinson | | #36

    Dave, I would never try to fix one of these nightmare homes. The owners should move out, call lawyers and insurance companies and have the home demoed. And no one who has allergies or asthma should ever use any spray foam. Sheet foam on an exterior would most likely be fine.

    Spray foam contracts should come with an insurance policy equal to the value of the property.

    Good post Dave, I wish I could feel a bit more calm about these nightmares but they are truly nightmares for some people if what they say really has happened to them.

  37. 2tePuaao2B | | #37

    If these problems are evident the products are not safe and therefore should not be promoted as green. Defend it and make excuses for the failure, but that is not going to make it any safer. Too many potential points of failure already known and proven. The un-knowns are yet to come .
    I am simply concerned about human health over efficiency here, It's not worth the gamble Martin.
    I consider advise given as suggestive Martin, glad to see that you are on top of the details!

  38. Allan Edwards | | #38

    I know several clients who have used spray foam in new homes with absolutely no problems. I know several builders using it with no complaints. A few people posting on a forum does not seem to me to represent a fair statistical sampling, especially when it appears all or retrofits. Martin, you have to be the voice of objectivity, what is your take on this just in terms of air quality.

  39. homedesign | | #39

    The thing that strikes me about these "testimonials"
    I could not find a single one that was posted by more than a First Name
    Did I miss a full name?
    Maybe these stories are true...maybe not
    just sayin

  40. Dave | | #40


    I think your post is extremely unhelpful and if you ever experienced what so many have been through with this spray foam you would never be posting such a ridiculous comment. Why do you care about someone's full name? Would you prefer to go to these homes and breathe in the odors and chemicals that are now present? Would that satisfy you? If you had a problem with your own installation you would be posting to try and get advice from others with the same problem. We are individuals who chose a solution that was sold to us as being "extremely" beneficial for making our homes more energy efficient and as a result of many factors now have a product that has caused all sorts of problems. This forum is one of the only outlets we have found to try and get advice and support from others who are in a similar situation.

    If you don't agree with the comments or believe the " testimonials" then maybe your comments would be more useful elsewhere.

  41. GBA Editor
    Martin Holladay | | #41

    As a journalist, I could not report on this story unless I was able to report the names of those providing testimony.

    That doesn't mean that the anonymous posters on this Web site aren't telling the truth. However, the jury is still out on this story.

  42. 2tePuaao2B | | #42

    The material manufacturer will surely share truthful information about this ongoing problem. Even with a slant, proof of the problems exist. The jury is in.... guilty.

  43. 4HCR9rhnie | | #43

    I had Demilec Sealection 500 (two part open cell urethane) installed into my home this past November. It has been an absolute nightmare. Same issues as other posters. Constant odor and associated resperatory distress. Unlike other homeowners, I ventilated the space from day one (for four months now), and it has not helped one bit. I have spoken with the EPA and I am in the process of undergoing independant air testing. From my discussions with EPA it has become apparent that removal of the foam can create its own set of new problems as airborn particulates created when the foam is disturbed can present additional problems. I Am a lawyer, though I do not specialize in tort actions or product liability. I am however looking to connect with other homeowners who have had a similar problem. I have little doubt that in the end I am going to have to tear out the shingles, roof decking, and rafters to resolve this nightmare. God only knows what the long term effects of this exposure will be. I would like to coordinate a discussion group and share experiences, health problems, and test results.

    This is not meant to be an attack on the industry. I am not trying to engage those of you who have had good results from properly installed foam. My concern is finding a way to help myself and those others who have experienced the nighmare of issues relating to an improperly installed product.

    Pease contact me at [email protected] only if you are experiencing similar problems.

    Upstate NY

  44. DJDt5kTWRX | | #44

    I figured I would post an update on my own situation with my odor problem in my attic after having Demilec Sealection 500 installed about a year ago. Throughout the winter months the odor was less noticeable although still present. Certainly heat and humidity play a large role in my own situation and cause the odor to be much stronger. In initial IAQ tests there were several chemicals found that were at dangerous levels. However, it was determined that it was likely coming from a product used to air seal in another location in my home. This was based on information found in the MSDS for a product called Touch and Seal which is often used for air sealing. The IAQ results and findings seemed to conclude that the various chemicals all mixing together were causing the overall odor. However, the odor has always been the most potent in my attic space where the Demilec product is installed. The Demilec foam was also baked in extreme conditions in a lab to determine whether chemicals in my home were coming from that foam. They did not see them at least based on where the IAQ tests were conducted but I have never been convinced about the chemicals potentially coming from Sealection 500.

    The plan was to first try and identify the source of these chemicals and see what could be done with the source. The biggest problem with spray foams seems to be that you can't successfully remove it without further problems. First, the foam has penetrated into all the material it has been sprayed on and second it releases many particles in the air. Other people have posted that they would need to remove their entire roofs etc. in order to completely remove the foam. In my own situation an HRV was installed to try and have a continuous exchange of air. The home was borderline on being too tight so it should have been part of the plan anyway from the start of the project. Further IAQ testing was done about a month and half following the HRV installation. Tests were conducted in more locations than the initial test. The results came back and everything had dramatically improved. There was some presence of the most dangerous chemical but was present at a very low number. This was at least a promising step forward that maybe we could live in a home without dangerous chemicals.

    Despite the success in diluting the pollutants with the HRV the actual odor was still present in the attic. Since it is impossible to remove all of this foam in the attic the plan going forward might be to close off any interaction with the attic air. This would include sealing all of the penetrations between my living space and attic. I am also wondering if removing all foam at the soffit and ridge vent to allow some venting again would be worthwhile but this would mean we would need to re-insulate the floor of the attic. I don't know if this is the best approach or whether it is better to leave it sealed and just seal off the penetrations. Any advice on this would be appreciated. We have a lot of recessed lighting which seems to allow a lot of the air transfer especially during my air conditioning seasons. In addition there are areas in the attic that were not properly sealed at the time of installation around the soffit which was allowing outside air to come though. Demilec has always claimed that this was one of the biggest flaws of the installation. The attic was never properly sealed. Despite that argument I will never allow any spray foam to be applied in my home again. At this point we hope to just close off any interaction with the attic air and hope to eventually put this terrible problem behind us. Unfortunately, I think there is still not enough known about the chemicals in these foams and what happens after they have been sprayed.

  45. 48KhFGjPAX | | #45

    The short answer the odor may NEVER go away. Some of the undesirable byproducts of closed cell foam system maybe solid tertiary amines which smell like fish. It may take decades for these solids to sublime. If your attic was sprayed your home may be destroyed. Open cell foam can be removed. Closed cell foam is five times more difficult to remove. I think it could cost $20,000 or more to remove the foam.

  46. 48KhFGjPAX | | #46

    I think you will have to tear off and replace the roof. Polyurethane foam is just a defective product.

  47. user-1004357 | | #47

    My name is robert and I'm the northeast sales manager for a large foam manufacturer. You can reach me at 860-933-7076. Our company offers AIA as well as educational spray foam presentations at no charge. If after reading all of the articles you're unclear or uncertain on any aspect of spray foam please feel free to contact me.

  48. user-1042388 | | #48

    The solution with the lowest expense and effort may be to rent a commercial ozone generator and let the house "bake" for a couple of days, The ozone oxides and cures many solvents and chemicals. Close all windows and turn the furnace fan to the "On" position to help circulate the ozone. It may also help to put a fan near the attic entrance. All humans, pets and indoor plants need to be moved to a hotel or friends during the treatment. When you are ready to see how the ozone worked, hold your breath, go into the house and turn the ozone generator off, and leave again. 20 minutes later, all the ozone will be gone, and it is safe to come back in again. If you are not happy with the smell, bake for another couple of days. This treatment also works wonders on mold.

  49. Richard Beyer | | #49

    # 48's comment is a very dangerous one and should be removed from this link. Ozone is very dangerous when used by an individual who has no prior training with it's safe use. This is just one more man made device which can cause irreversible health issues when used by a man with no prior training and/or understanding of the hazards associated with it's use.

    Proper respiratory protection, ventilation and training is required for the safe use of Ozone. Commercial Ozone machines emit large doses of ozone can permanently damage electrical wires, plastics, rubber and many other building materials. It is a miracle solution to many common VOC and mold issues when used correctly. This does not mean the source of the problem will become completely obsolete after it's use.

    20 minutes of fresh air ventilation is misinformation and a dangerous recommendation especially for those who already have compromised immune systems. Ozone can damage lung tissue when inhaled even in small doses.

    Only hire a professional who has been properly trained with the safe use of Ozone. Thoroughly understand the risks associated with it's use. Ozone is not a cure all!! Source remediation is the only solution.

    The below chart was taken from an engineering blog about Ozone and it's half life. As you can see 20 minutes of fresh air is not even close to accurate. Ozone gas could be trapped in closet's, void in construction, building material's trap the gas and on and on.

    Typical O3 Half-Life Time as a Function of Temperature
    half-life time at Temp half life time at Temp

    Ozone in Air ~ Ozone in Water
    ~ 3 months -50 ºC (-58F) ~ 30 minutes 15 ºC
    ~ 18 days -35 ºC (-31F) ~ 20 minutes 20 ºC
    ~ 8 days -25 ºC (-13F) ~ 15 minutes 25 ºC
    ~ 3 days 20 ºC (68F) ~ 12 minutes 30 ºC
    ~1.5 hours 120 ºC (248F) ~ 8 minutes 35 ºC
    ~1.5 seconds 250 ºC (482F)

  50. robingers | | #50

    Wow, I'm so glad I found this site and thread. We have had problems with our attic and the spray foam too. It's been 5 years and we are still experiencing the smell problems. Mostly when the weather heats up is when the smell gets bad. We do not have any venting in our attic, as we were told it would counter the energy-efficiency benefits of the insulation. The smell is worse this year and we think it may be that the ductwork in the attic may have a leak. It is flexible and I have read it is more prone to leaks than the metal kind. At this point we are looking into putting in venting and replacing the ductwork. Since this thread is kind of old I wanted to check to see if you were ever able to rectify the situation? I hate to say it, but I think we may need to litigate at some point to get this problem under control so others won't have to suffer like we all have. I have health issues, which have worsened ever since we moved into this house, and I think it may be because of the toxicity of this spray foam. BTW, our home was new, and the foam was installed when the house was built. I know some threads mentioned that maybe the issue was with retro-fitting the foam, but that is not the case for us. Also, someone had posted that this may be an isolated problem, because it seems like only a few cases of this happening. But I would venture to say many people are experiencing this, but like us, just thought we were overly sensitive to smells, and also never researched it enough to see others were having this problem too. Would love to hear if you have any suggestions to help. Thanks so much!

  51. GBA Editor
    Martin Holladay | | #51

    Here is a link to an article on the topic: Spray Foam Jobs With Lingering Odor Problems.

  52. Rin4 | | #52


    Did you ever find a solution to your problem? We just had spray foam applied a month ago with the promise of it being "odor free", etc, and it still smells so strongly of paint that I'm afraid to let my daughter sleep in her room upstairs. This is particularly strong during a sunny day. This is our dream home and it's been ruined by this horrible stuff. We had Bayseal Open Cell and I just want to know if this is something that eventually corrected itself over time or if you found relief any other way. Like I said earlier, this is our dream home and I live in fear of the top floor being full of toxic off-gassing from the fumes. We are getting pretty close to having the roof and trusses ripped off and replaced. Did you find anything that ended up doing the trick?

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