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Is Icynene spray foam a problem for peopleWith chemical sensitivities?

green654 | Posted in Green Products and Materials on

Hello. We are building a new home and the builder wants to build a conditioned attic space using icynene spray foam. He says it’s non toxic. I’m sensitive to odors and chemicals and I’m a bit concerned about this. He believes The benefits of a conditioned attic are endless. My gut is leaning towards going with an unconditioned attic and using rockwool or cellulose insulation to avoid the chemicals. Thoughts?

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  1. user-2310254 | | #1

    If you are sensitive to chemicals, I would avoid spray foam. A conditioned attic is great if there is no other way to install an HVAC system. If you have other options, then it's just another large volume of space that has to be heated and cooled (to some degree).

    Cellulose often delivers more bang for the buck as well. Usually you can install a lot more cellulose and still go out ahead budget-wise.

    1. green654 | | #2

      Thank you for your response!

  2. Expert Member
    Michael Maines | | #3

    Spray foam is technically non-toxic once cured, but in my experience it often has a residual odor, and it's the only common insulation type that on occasion does not cure properly, leading to more serious odor problems. I use it sometimes when nothing else will do the job, but for a chemically sensitive client and a situation where it's not the only product that will do the job, there is no way I would risk it.

  3. Expert Member
    BILL WICHERS | | #4

    Properly cured spray foam is a very stable material and shouldn't be a problem. The first few days to a week there will be a smell, and I'd try to stay out of the house for at least a few days immediately after application. The issue is that IMproperly cured spray foam can be an ongoing problem in terms of smell. If you get an experienced contractor, you shouldn't have any problems. I do recommend doing the installation on a Friday though, and then going away for the weekend while leaving some windows cracked open on the house.

    All of that said, a non-conditioned (vented) attic is lower risk all around, and cheaper. If you can do a vented attic, with loose fill (blown cellulose, fiberglass, or mineral wool), you have much less potential for anything to go wrong, and you save money too. This is the route I'd take myself -- conditioned attics, in my view, are something that should be built only when needed. If you have a way to do a vented attic, that's preferable in my opinion.

    I recommend spray foam only for niche applications where it's the only real option. This usually means cathedral ceilings, rough (cut stone) foundation walls, and sometimes rim joist areas. "Regular" attics have other options, and with walls spray foam is just a waste offering little if any practical benefit over other insulation types and conventional air sealing. The last thing I'll mention is that I'm one of the most pro-spray foam people here on GBA, and even I think your builder is overselling spray foam here...


  4. walta100 | | #5

    In my opinion the only time a conditioned attic make any sense if poor choices were made and now you must somehow live with the poor choices. HVAC equipment and ducts in the attic is a very poor choice and some time it is possible to undo. Half story second floors are all but impossible to air seal as a renovation. These poor choices will raise your utility bills about 50% with a vented attic and 40% if you condition the attic. Making the conditioned attic slightly better than the very bad option you likely have now.

    Since you know you are sensitive it seems like a poor choice to add more chemicals to your environment.


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