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Help! Our contractor installed some toxic stuff!

GBA Editor | Posted in Green Products and Materials on

After an 11month process of choosing low VOC materials for our remodel, we came home one day to find that our flooring contractor has put down some pretty nasty waterproofing material in the room that is to be our bedroom – where we’re hoping to have a baby sleeping soon, and then put an engineered flooring material on top of it.

The product is Bostik MVP4

Does anyone know what we can do about it at this point?

Does anyone know if offgassing will continue to happen despite the flooring material on top of it?

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  1. User avatar GBA Editor
    Martin Holladay | | #1

    As far as I can tell, Bostik MVP4 is designed to be installed under flooring material. Do you believe that your contractor installed it in a way that was not recommended by the manufacturer?

    Unless you have a specific reason to believe that your family has special health conditions, you may be worrying unnecessarily. I would contact Bostik to learn whether your contractor's use of the product met the manufacturer's recommendations.

  2. Ben r | | #2

    Just discovered that the contractor also put down some glue over the waterproofing, which may actually seal the waterproofing (?), but is nasty in and of itself.
    VOC: 86 g/L

    versus the VOC: 126 in the waterproofing material.

  3. Ben r | | #3

    Hi Martin. Thanks for the quick response! (much appreciated as we are super stressed about this right now).

    No, we have no reason to believe that they didn't install correctly. We're worried though, given that there are low VOC products on the market, that the implication is that the higher VOC products would offgass through the tounge & grove flooring.

    We're wondering if we should go through
    a) the terrible headache of removing the newly installed flooring and the waterproofing+adhesive.

    b) sealing the wood with some sort of material that would prevent offgassing


    c) are we worrying too much about offgassing through an engineered floor?

  4. User avatar GBA Editor
    Martin Holladay | | #4

    Since you're asking, I'll answer: I think you are worrying too much.

    A lot of the worry about VOCs is unscientific. Some of it, however, relates to special medical conditions, including multiple chemical sensitivity. If you or members of your family have special medical conditions, you should ask your physician these questions.

    Otherwise, tell the contractor to open the window and turn on the fan.

  5. Riversong | | #5

    I think that Martin is being far too cavalier about a bedroom for a baby. Infants are far more vulnerable to minute doses of toxins, mutagens and carcinogens. Exposure to indoor VOCs, particularly formaldehyde, can be the trigger for Multiple Chemical Sensitivity.

    If you had a clear understanding with either the flooring contractor or whichever contractor hired him/her, then I would have the responsible party remove the entire flooring system at their expense. If not, then perhaps you could have an air sample tested to determine whether you want to undertake the expense of removal.

    The MSDS documents for both those Bostik products indicate considerable potential for toxic and possibly carcinogenic effects. If you chose to use healthy products in your remodeling project, then there's no reason to settle for anything less. The human immune system is under considerable stress from the thousands of toxic substances in our indoor and outdoor environments. In our homes, we should have the choice to live toxin-free.

  6. Trina Masepohl | | #6

    I agree with both Robert and Martin... BUT I'm taking Robert's stance on this one and here's why. GreenGuard produced a fabulous report titled "Chemicals in Common Products: Risky Business for Children's Health" ( In it they discuss, through countless references, how children's systems are not like "little adults" and that the effect of combined indoor air toxicants on children's developing systems is of concern. Furthermore, young children are closer to the ground and have the tendency to put anything and everything in their mouths. While some VOCs are likely to only cause acute symptoms of eye, nose and throat irritation, other VOCs have been shown to be quite damaging: benzene is a known human carcinogen; trichloroethylene has been linked to childhood leukemia; toluene is linked to reproductive and developmental problems; xylenes cause birth defects in animal studies; and styrene is linked to endocrine disruption. Formaldehyde, although usually discussed separately, is also a VOC and is a known human carcinogen, as well. BTW, this is all referenced from a CDC report called the Healthy Housing Reference Manual; you can find it online. And this information can all be corroborated through multiple references from the CDC, EPA, GreenGuard, countless scientific and medical journals and more. It's not just some scary stuff I pulled from random online articles. It keeps showing up again and again and again...

    So... I'm not sure I would categorically say that "the worry about VOCs is unscientific".

    If it were my child and knowing what we know now, I would find a way to get the problem fixed. After all your efforts to build green, this seems like a significant error on the part of your building team.

  7. Jeff L | | #7

    I think you all have valid points however consider this, what kind of floor do you want? I have not seen any superior product that is more "green". Perhaps you should find out if you can even get a better product before making a decision. Or maybe a concrete floor or tile floor would be better. There are very few other options out there.

  8. Allison A. Bailes III | | #8

    Here's another option: Provide extra ventilation for that room until the off-gassing has diminished and keep the baby out of there until then. It's cheaper than ripping up the whole floor, and I agree with Martin that the VOC issue is a bit hyped.

    If you've got an ironclad contract that specifically forbids the builder and trades from using those materials, then you could have them rip it up and redo it, but it's not very green to create a lot of unnecessary waste either.

    Allison A. Bailes III, PhD
    Energy Vanguard

  9. B. Wright | | #9

    Our bodies all react different, and with the many cases out there with MCS, CFS and the increase rate of children with allergies, the above concerns should not be downplayed - contractors need to give it the respect and attention it deserves.

    The product mentioned is essentially a urethane compound - known as a carcinogen if ingested. To some degree it has VOCs, but locking it (sealing) would only slow down off gassing but not rid it of such. My suggestion would be to remove the compound, and question the need for this moisture barrier in the first place. If needed, then there exists some non-toxic vapour barriers used prior to floor installation below-grade (very thin mat you can roll out).

    I would then question the flooring type. The best flooring option is reclaimed or natural hardwood (ex: For engineered, choose a known manufacturer to get proper info on adhesives as they may also have VOCs. For installation, you can nail it down, or glue tongue and groove systems together with non-toxic, no VOC carpenter's glue, or have floating Clip systems. Hardwood (non-engineered) proves to be the best for your health, and your baby's.

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