GBA Logo horizontal Facebook LinkedIn Email Pinterest Twitter Instagram YouTube Icon Navigation Search Icon Main Search Icon Video Play Icon Plus Icon Minus Icon Picture icon Hamburger Icon Close Icon Sorted

Community and Q&A

Anyone use Dennyfoil to block fumes from a renovation?

daisy63 | Posted in Green Products and Materials on

A Contractor is renovating two walls in my apartment near the windows. I’m very chemically sensitive. one suggestion is to place dennyfoil on the wall to block the fumes from coming into my apartment.

Has anyone used it successfully for this purpose and have any suggestions
On how to reduce the risk of mold growing. One person suggested applying the foil tightly to the wall using tape. To not use the air conditioning. And to consider getting a dehumidifier when it’s humid in my apartment.

She also recommended I consult with a building science expert. Any advice or feedback?

Is it realistic to use this for this purpose short term, versus long-term. it would have to stay on the walls to continue to block the fumes in order for me to live in the apartment


GBA Prime

Join the leading community of building science experts

Become a GBA Prime member and get instant access to the latest developments in green building, research, and reports from the field.


  1. Expert Member
    Dana Dorsett | | #1

    The use of foil vapor barriers in a wall would be effective in blocking gases of all types from passing through it, but the wall's material stackup needs to be assessed relative the local climate to see if installing a vapor barrier would cause a problem.

  2. GBA Editor
    Martin Holladay | | #2

    Q. "One suggestion is to place Dennyfoil on the wall to block the fumes from coming into my apartment. Has anyone used it successfully for this purpose?"

    A. I have never heard of Dennyfoil, so I did some Googling. It turns out that Dennyfoil is the brand name for an aluminum radiant barrier / vapor barrier. Here is a link to a relevant page: Dennyfoil.

    I have no idea what your plan is. Do you intend to attach this aluminum foil to the exterior side of the wall, or the interior side of the wall? If you want to keep fumes out of your house, you would need to install the foil in an airtight manner, which would require the foil to be attached with all seams taped with compatible tape. I can't visualize this as a sensible solution. For one thing, the aluminum foil is fragile. For another thing, it can trap moisture in the wall and lead to mold growth or rot.

    Q. "On how to reduce the risk of mold growing: One person suggested applying the foil tightly to the wall using tape [and] to not use the air conditioning. And to consider getting a dehumidifier when it’s humid in my apartment."

    A. Again, we need to know whether you plan to install it on the interior or the exterior side of the wall. In either case, it sounds totally impractical. My guess is that you want a solution that allows you to continue to use your air conditioner.

  3. GBA Editor
    Martin Holladay | | #3

    Why do you think that the planned renovations will reduce dangerous fumes? What fumes are you worried about?

  4. daisy63 | | #4

    Thanks for responding. After they finish renovating two walls in my apartment-they’re replacing brackets and insulation in the wall and then they close up the wall, re plaster and paint, then when things are dry they would apply the dennyfoil to the interior wall in my bedroom and living room.

    I checked out one apartment where they did the work and I have bad reactions to the outgassing of these renovation materials that were used for the wall work. I have severe chemical sensitivity.

    I think it’s just a short term Band-Aid until I can find more suitable housing, and not a long-term fix for me to live there.

    I didn’t say because of fatigue, that I used dennyfoil before. Maintenance applied it very loosely around the window frame and the wall below frame where they used caulk that I was reacting to. It Also was applied underneath the exhaust vent for my heat/air conditioning. I don’t think it was applied very tightly to the wall. I read on some forum that one person who used it, said if it wasn’t applied tightly that there’s less risk of mold growth. It was on for about a year. The problem that I saw was that mold grew on the wall underneath exhaust vent. So I assume that using the air conditioning was a reason mold grew?

    I wondered if mold could grow within the wall and it wouldn’t be visible because of you using dennyfoil? Is it possible to talk to anyone at Green building advisor directly regarding this project? I have chronic fatigue, so I have a hard time formulating what I need to say to get help online.

    I need to inform people what experts say Who are more knowledgeable. I don’t think that this is a long-term solution and that I would need housing very soon that is safer, with no recent renovations.


  5. Expert Member
    Michael Maines | | #5

    Daisy, since I advised you to ask here I'll chime in. Not everyone at GBA is sensitive to chemical sensitivity, but I think your core question can be boiled down to this: In what situations would a temporary interior vapor barrier be safe or unsafe regarding mold growth within a wall assembly. If you tape thick foil to the wall I don't believe significant VOC's (volatile organic compounds) would get through, but it would need to be very tightly taped with a high-quality tape, and will probably peel paint off when removed.

    What you had asked me was if the foil would cause mold growth in the wall. For that we would need to know what is the wall assembly, where are you located, do you need to use air conditioning, and how long does the foil need to be on the walls.

  6. user-2310254 | | #6


    It sounds like you need a temporary fix that will hold until you move. It may not be possible to prevent all the chemical odors using any practical method. But if I were you, I would ask the contractor to install painter’s plastic over the partition wall (taped at the perimeter). If the weather was nice, I would put a box fan in a window and use it to ventilate and slightly over pressurize the apartment.

  7. GBA Editor
    Martin Holladay | | #7

    Now that you've provided more of a description, I'll sum up. Tell me if I got this right.

    1. The renovation work is occurring indoors, not outdoors.

    2. The contractor will be installing gypsum drywall, drywall mud, and interior paint on the wall. You are sensitive to these fumes.

    3. You want to cover the interior wall with aluminum foil after the painting work is complete.

    Here's my reaction to the plan: Attaching aluminum foil to a recently painted wall with tape will probably damage the paint job, because of all the necessary tape. It might be easier just to tell the contractor to skip the paint. Of course, you might be sensitive to drywall compound (mud), so that wouldn't necessarily solve the problem.

    Even if the aluminum foil is installed with attention to airtightness, I doubt if you could do an airtight job, and smells might still be detectable. And as I pointed out earlier, the foil might get damaged.

    Is it possible for you to leave the window open for a few days after the work is complete -- perhaps with a fan in the window to encourage ventilation -- while you sleep at a friend's house?

  8. daisy63 | | #8

    Thanks for the responses! I’ll have to get back to you soon regarding the questions asked of me. I did speak to Foust regarding usage of dennyfoil. I purchased the foil from this company

  9. daisy63 | | #9

    Hi, Would you say that Overlaping dennyfoil sheets about 3 inches so no gaps between 2 sheets would be sufficient?
    How many inches would you tell workmen to overlap 2 dennyfoil sheets when applying to wall.

    I have concerns that there’s no gaps far outgassing to seap through since I am very chemically sensitive.

    I have to ask the manager about the wall assembly. And someone else suggested I ask If an exterior vapour barrier is on the exterior wall. And I’ll fu with all answers to questions asked last week.

    Thanks for all your help and suggestions!

  10. GBA Editor
    Martin Holladay | | #10

    Honestly, I don't think your project is a good idea. But from an air sealing standpoint, you don't need 3 inches of overlap. You only need 1/2 inch or 1 inch of overlap, as long as you are taping the seams.

    The integrity of this new air barrier will only last until someone bumps against the aluminum foil and leaves a hole or tear. I suppose you can buy an extra roll of aluminum tape, so you are ready to repair any damage.

    It's hard to predict whether this aluminum foil layer will cause moisture or mold problems. Suffice it to say that the foil-covered assembly will be safer in cold weather (when your heating system is operating) than in hot, humid weather (when your air conditioner is operating). In some climate zones, you might end up with a layer of mold behind the aluminum foil if your air conditioning season lasts a long time.

  11. daisy63 | | #11

    Thanks Martin for your response! I’ll pass on what you said to the property manager. Sorry for the delay in responding, dealing with health problems

  12. daisy63 | | #12

    In response to these questions:
    What is the wall assembly and Is an exterior vapour barrier on the exterior wall?

    the property mngr said:
    There is no vapor barrier that has been installed in your apartment. The wall board that was replaced is the standard gypsum wall board that is used.

    I live in Boston, MA. It can get humid inside and outside the apartment. I don’t need to use air conditioning. Please advice, If you think I should avoid using air-conditioner to reduce the chance of mold growth. I think I have to avoid using it because the Denny foil is covering the wall were the walen unit is and the vent that the air would come out of and I think that this wall can get colder because the air is circulating up that wall.

    Do I need a very accurate humidity gauge to monitor the humidity. And do you think I need a dehumidifier for each room or whole apt, dennyfoil is on one wall in living room and bedroom. Would I need to check the wall sporadically behind the dennyfoil.

    The foil needs to be on as long as I’m living there, since I am so chemically sensitive that once it’s removed I would have symptoms - dry irritated nose, eyes and confusion. I had those symptoms when I checked out the apartment before they applied dennyfoil.

    I’m looking into a way to outgass the wall in each room so the foil will stay on a shorter time. Having the heat high is one way, but can’t use the heat until Sept.
    My understanding is that the foil reduces the outgassing of those materials. So I feel it’s a short-term fix

    Thanks for any advice you can give me

    What you had asked me was if the foil would cause mold growth in the wall. For that we would need to know what is the wall assembly, where are you located, do you need to use air conditioning, and how long does the foil need to be on the walls.
    Answered by Michael Maines

  13. Jon_R | | #13

    Long term, I would look into installing a HRV and running it at higher than normal ventilation rates. Also have it balanced for slightly positive pressure.

  14. daisy63 | | #14

    Hi Jon, what does HRV stand for? Thanks

  15. Jon_R | | #15

    Heat recovery ventilator - a fan like device to replace polluted indoor air with outside air while wasting less heating/cooling energy.

    Is your health better when windows are open?

    Maybe there are some wallpapers that could be used instead of paint.

Log in or create an account to post an answer.


Recent Questions and Replies

  • |
  • |
  • |
  • |