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Product Guide

The Promise of AeroBarrier for Air Sealing Homes

AeroBarrier West is using this air sealing system on existing and even occupied homes

AeroBarrier West air sealing an occupied, existing home. Photo courtesy of AeroBarrier.

AeroBarrier has been in the building news quite a bit lately:

How AeroBarrier Works

AeroBarrier is an innovative and sophisticated system for air sealing buildings. During installation, a proprietary synthetic acrylic is aerosolized while the home is under pressure developed by a blower door. As the air leaks through the building enclosure, the latex aerosol sticks and builds up on pretty much any crack up to about ½-inch.

AeroBarrier is installed using a system of equipment seen here in a fully outfitted construction trailer. Photo courtesy of AeroBarrier.
During installation, the AeroBarrier system is controlled by software that keeps track of blower door pressure, pressure delivered at aerosol heads, temperature, and relative humidity inside and outside the building. Photo courtesy of AeroBarrier.

AeroBarrier aerosol head fired up to seal leaks using positive pressure delivered by blower door. Photo courtesy of AeroBarrier.

Blower door outfitted with an inline heater to ensure that proper temperature is maintained inside the building during the air sealing aerosol process. Photo courtesy of AeroBarrier.
In this AeroBarrier project, an exterior 6-inch exhaust duct was outfitted with a taped-in mesh to show how the aerosol fills in and seals. Photo courtesy of AeroBarrier.
The mesh sealed after AeroBarrier installation. Photo courtesy of AeroBarrier.

In under 2 hours, a home can move from leaky to pretty much whatever level of air sealing you are prepared to pay for.

You do, of course, need to prep the building, air sealing pathways larger than ½-inch, but following the Energy Star Thermal Bypass Checklist heavy hitters is straightforward.


Air seal needed at eave prior to AeroBarrier process. Photo courtesy of U.C. Davis Western Cooling Efficiency Center.
Thermal bypass rough cut insulation and perimeter spray foam sealed prior to AeroBarrier process. Photo courtesy of U.C. Davis Western Cooling Efficiency Center.

You can use AeroBarrier before cavity insulation is installed (essentially completing an exterior air barrier) or after drywall (essentially completing an interior air barrier); in either case requiring pretty limited protection of finished surfaces.

The real beauty to me of the AeroBarrier approach is that it is real-time performance-based. The blower door testing and results is built into the AeroBarrier process.

AeroBarrier in existing buildings

If an existing building is between occupants, there will be protection of more finished surfaces required—and the bigger thermal bypasses still need to be at least “rough” sealed—but that does not seem like that much of a jump from AeroBarrier post-drywall in new construction.

Paul Springer, manager of business development for AeroBarrier, connected me to Mitchell Spence of Redfish Builders, the leading AeroBarrier partner doing existing homes. Springer stated that about 10% of the AeroBarrier partners nationwide work on existing buildings but they do this completely on their own. Springer also noted: “We do have a new grant from the DOE in which we are going to be applying AeroBarrier in finished spaces (non-occupied) to understand the benefits.”

“About 10% of our air sealing business currently is AeroBarrier in existing homes,” says Spence. “The key for us managing the liability of damage to contents is our partnership with a painting company. They know how to rigorously and efficiently seal everything from clothing to furniture to floor coverings and we know how to seal the building.”

Spence feels the other key to his AeroBarrier work is his background in high performance building at Redfish. It’s his knowledge of the building process and business partnerships with trade contractors and other builders that means AeroBarrier work on new production homes, new custom homes, existing homes, and multi-family projects.

Spence has tuned his air sealing of existing buildings with AeroBarrier. “I pretty routinely suit up with respiratory protection to first target my Retrotec fogger  at suspected leaky areas and then relocate the AeroBarrier spray heads to target those leaks. I also use “first sweep” during AeroBarrier air sealing, brushing off aerosol that is going after surface leaks encouraging aerosol sealing a bit deeper into existing building assemblies.” Spence also noted that quite a bit of the prep for holes and cracks larger than ½-inch gets addressed with closed-cell backer rod, which costs about $100 for a 500 foot roll off of Amazon.

The following images are various types of prep completed by Mitchell Spence’s painting contractor in occupied existing projects.

Painter prep in rec room Photo: Mitchell Spence
Note how the carpet has been pulled back from exterior walls and the bed fully sealed. Photo: Mitchell Spence
Sealing off all fixtures in a bathroom. Photo: Mitchell Spence
Masking off kitchen appliances and cabinetry. Photo from CEE report: Using and Aerosol Sealant to Reduce Multifamily Envelope Leakage.

Spence is a big advocate of AeroBarrier for multi-family air sealing. “We can do unit-by-unit AeroBarrier work, not only sealing the building enclosure but between units. This has big indoor air quality and sound transmission benefits,” says Spence.

Using two duct blaster fans to pressurize an existing MF unit to 100 Pa for AeroBarrier air sealing. Photo from CEE report: Using and Aerosol Sealant to Reduce Multifamily Envelope Leakage.
From early work on aerosol sealing of multi-family units comparing the labor for new construction, existing, and existing occupied. Chart from CEE report: Using and Aerosol Sealant to Reduce Multifamily Envelope Leakage.
Tested results. Chart from CEE report: Using and Aerosol Sealant to Reduce Multifamily Envelope Leakage.

How AeroBarrier in existing buildings could be a game changer

Increasingly, as I do assessments and investigations of existing buildings, performance concerns of the building owners are rooted in air leakage, from comfort complaints to more serious moisture issues. And those same clients often have questions and concerns regarding spray foam as pretty much the only game in town for seriously improving the airtightness of existing buildings.

I think that AeroBarrier in existing buildings can give spray foam a real run for its money in many of the 100+ million existing dwelling units we have in the US. An aggressive and elastic yet largely benign acrylic aerosol (see AeroBarrier MSDS) could be just what our existing building stock needs to safely improve the toughest aspect of existing building performance: airtightness.

But how much does it cost?

Spence told me that for occupied homes AeroBarrier runs between $3 and $4.25 per square foot of building but it makes a big difference what type of building. “Large custom homes can be up to $7 per square foot including both prep and AeroBarrier process,” says Spence.

What do you think?

Peter Yost is GBA’s technical director. He is also the founder of a consulting company in Brattleboro, Vermont, called Building-Wright. He routinely consults on the design and construction of both new homes and retrofit projects. He has been building, researching, teaching, writing, and consulting on high-performance homes for more than twenty years, and he’s been recognized as NAHB Educator of the Year. Do you have a building science puzzle? Contact Pete here.


  1. John Clark | | #1

    I like the idea but I wonder it it's any less resilient with regards to daily thermal expansion and customary settling of the structure itself.

    I think of it as an interior applied liquid WRB.

    1. User avater GBA Editor
      Peter Yost | | #12

      Hi John -

      Big concern of mine too is the service life of AeroBarrier as an air sealing method. I do like the fact that the "sticky stuff" is acrylic, since in my testing of PSA tapes, acrylic adhesives fared the best with lots of different substrates and cold and wet as well as hot and dry.

      There has been a lot of research on AeroBarrier and longitudinal testing by Dave Bohac at CEE in Minnesota and my understanding is that sustained performance has been good, at least for some years.

      I also know that Steve Baczek and Jake Bruton have a couple or so of Jake's homes that have/will get the AeroBarrier system and Jake is going to be blower-door testing these homes over time.


  2. Trevor Lambert | | #2

    I'm not sure about existing homes, but this makes zero sense for new construction. Just design the house properly, and pay attention to details while you build it and <1.5ACH is very easy. A 2500 square foot home would cost between $7500 and $10,600 using Aerobarrier. There's no way you'd spend close to that much using taping, etc. The only scenario this makes sense for is if you realised part way into construction that you forgot (or hadn't yet learned the importance of) air sealing details, or at blower door testing stage you found out some of your subs didn't do their jobs; a last resort to fix a big "whoopsie". Not as a primary means of air sealing. Planning on Aerobarrier from the start is like installing tires on rims without sealing the rims to the tires and using "fix-a-flat" when you inflate them.

    1. User avater Expert Member
      Dana Dorsett | | #3

      The cost for existing homes is indeed daunting. Even spending the same amount of money on rooftop PV is likely to have a better net energy ROI.

      1. User avater GBA Editor
        Peter Yost | | #21

        Interesting Dana.

        It did not occur to me to compare PV and air sealing based on ROI because a big part of air sealing existing homes to me is about thermal comfort, indoor air quality, durability, moisture management.


    2. Sean Conta | | #16

      The cost in the article is for occupied homes, new construction is quite a bit cheaper (I just did this on my project).

      I must say you're living in a bubble if you think that getting under 1.5 ACH50 is "very easy" for a huge number of builders in this country (who aren't reading GBA and have never used tape). The real potential for AeroBarrier is that market, not us GBA dorks! :D

  3. Alan B | | #4

    These aeroseal people are like vultures, they trawl the internet and anytime someone mentions them or a concept close enough they show up to hawk their wares. And then the grandiose claims, then the arguing with anyone who disagrees with them, its like a messed up evolutionary offshoot of multi level marketing.
    If anyone even asks about the toxicity or durability its likely they will show up and start spamming us. Though i hope this forewarning will keep them away.

    All that said it would be far cheaper to hire a blower door tech, find all the leakage vectors you can, list or photograph them, seal them, repeat and seal more if necessary. I don't know what the going price for a blower door test and letting it run for 15 minutes is but i imagine its vastly cheaper.

    If your walls and ceilings are made of mesh screens instead of solid matter then aeroseal may be your best option though it will have no R value, just air sealing value.

    1. JohnP123 | | #22

      The testing has been done. VOC emissions and long term durability. Its as advertised.

  4. Ron Keagle | | #5

    If this sealing process is continued long enough, does it result in a 100% sealed building with no leakage whatsoever?

    1. User avater Expert Member
      Dana Dorsett | | #6

      Depends on what you mean by 100%. Percentages of what starting point, and how many signficant digits of accuracy?

      There is no absolute zero of air leakage the way there is with temperature. Even hermetically sealed enclosures for space grade microchips will pass some amount of helium, and are thus arguably not 100% sealed.

      From an energy and ventilation point of view the ~50 cfm/50 after 135 minutes shown in the graph is tight enough to be considered "as good as 100%" from a practical point of view. At that level of tightness energy and moisture impacts are WAY down "in the noise" of other building factors in a house.

    2. Expert Member
      Malcolm Taylor | | #7


      If they could get below 0.05 ACH @ 50 pascals, it would be the tightest house in the world

      1. User avater Expert Member
        Michael Maines | | #13

        A house I designed, built by Emerald Builders in Bowdoinham, Maine, shell tested at 0.12 ACH50. That's with no sprayed foam, just double-stud walls with cellulose and meticulous taping using Pro Clima products. I have a hard time seeing where Aerobarrier makes sense.

        1. Expert Member
          Malcolm Taylor | | #14


          The only way I can see it making sense is if it completely displaces other methods of air-sealing and becomes the accepted industry norm. For that to happen the price would have to come down substantially - and I don't know if that's possible.

          1. Alan B | | #19

            I think they want to preserve their margins.

        2. user-6765831 | | #17

          It might make sense for homeowners who don’t have time to become green building gurus and whose builders aren’t conscientious about green building techniques. It can make up for a lot of stupid. I’m sure you didn’t just accidentally build a house that air-tight.

        3. JohnP123 | | #23

          You make it sound like installing pro clima products is a walk in the park - or that the pro clima system is cost effective. Its expensive, its incredibly labor intensive to install and hard to ensure performance after sheetrock is installed. Everyone drinking the 475 koolaid needs to pump the brakes and accept that fact there are alternatives to the products and concepts 475 sells / markets and promotes. Aero barrier offers a cost effective approach to achieving low ACH performance without ensuring that every trade on a job site will follow through with their promise to put tape on any hole they create. There is room in the market for more than the 475 membrane and tape system for high performance homes. And yes, even room for spray applied foam. The more options available, the better for the performance of our buildings.

          1. User avater Expert Member
            Michael Maines | | #24

            JohnP123, I think I've tried every method out there at this point (except Aerobarrier) and I am not loyal to 475 or Pro Clima. But they have a good system that I've spec'd and or used myself many times and it's not that hard to do. Certainly less than spending $10K on Aerobarrier. But it does require some education. I don't expect subs to learn or care about building airtight; that's the GC's job. The tightest house I've done with spray foam was 1.7 ACH50. I thought it was good at the time, but it's not really.

          2. Deleted | | #25


          3. Sean Conta | | #26

            Reality check on cost: I just did AeroBarrier on a small home here in Seattle (new construction, before insulation) and it was about $1.40/ square foot of floor area. Obviously this varies based on a lot of factors including what dealer you're using, but it's one data point.

      2. User avater
        Tom Miller | | #27

        ICF houses are typically in the 0.25 ACH range without a lot of extra work. All walls ICF and roof using advanced wood framing techniques.

  5. user-6765831 | | #8

    So I want to leave a little perspective on my recent Aerobarrier experience. It was on a major remodel (down to studs) of existing home. I used it to supplement my own exterior air barrier. I put forth a pretty good effort with caulk, foam, and taping sheathing, but could still only get to 3ACH50. There were some limitations in a remodel situation regardless that would not exist with good planning in new construction, and I am sure I could do better next time if I kept doing this kind of thing.

    I negotiated 2.19 per SF in Bay Area for a 2000 sf home, though they knew I was doing my own air sealing ahead of time, and my situation was closer to new construction for them. They got me to 0.22ACH50. Of course, I had to take a couple of days off work since my GC wouldn't airseal beyond taping the sheathing. So you could say I paid for it one way or another. I worked with Western Aerobarrier and they were great, but I also had a great conversation with SDI insulation which is Bay Area based.

    Certainly, where I live it was not "cost effective" to use Aerobarrier when I was already at 3ACH50. I hope this will become cheaper as it is scaled up. I think there are a lot of situations where it is difficult, for a variety of reasons, for a homeowner to get a tight house and this is one solution, albeit at a high cost.

    When my house was being Aerosealed, it seemed like 0.2ACH50 was the asymptote for my house and that no matter how much longer we continued, it would not get any tighter. Later I found one large hole that had been missed during my own air sealing, around 1.5" sq, and the Aerobarrier hadn't filled it in at all. So maybe the theoretical max of house is less than 0.2, but there seems to be a limit to what it can do.


    1. Expert Member
      Malcolm Taylor | | #9

      Thanks Asaf, that's interesting to hear.

    2. Cory Holliday | | #10

      Is that 0.2ACH50 measured during the Aeroseal process with windows and ducts taped?



      1. user-6765831 | | #15

        That is an important clarification you made. This is the airtightness during the air sealing process so windows door and ducts taped. This is also pre-dense packed cellulose and drywall in my case. So not the “true” number yet and provided by the AeroBarrier technology. In a few months I’ll report here the final Ach50 from blower door when house is complete. As the ducting has been well sealed, It may give me some insight also as to how leaky these Integrity windows are.

        1. Cory Holliday | | #18

          Thanks Asaf,

          It will certainly be interesting to compare the numbers from different stages of the build. Best of luck with your build.


    3. User avater GBA Editor
      Peter Yost | | #11

      Thanks much for sharing this Asaf.

      Though we could not get this set up in time for this blog, I am very much hoping to get our home AeroBarrier-ed. I am at about 4 ACH50 after a 12-year, room-by-room deep energy retrofit ( and I don't really feel that I can get to many or most of the remaining thermal bypasses.

      I very much want to see the existing, occupied, AeroBarrier up front and personal, and to track by IR and fogging exactly where and how the air leaks get addressed by AB.

      Hearing your experience is really helpful.


  6. BrewerLarry | | #20

    I'm a curious consumer interested in green building with low knowledge of how all of this works. What strikes me about the AeroBarrier methodology is the potential to increase the air tightness of existing homes.

    The following scenario runs through my head. What if states implemented programs that required increased air sealing on homes when they sell? The AeroBarrier method could be used when the home is empty between people moving out and the next folk moving in. That would reduce the cost of having to seal furniture and and all the other items in a house that's being lived in. Perhaps states could offer a rebate for the work. Here in Oregon I could see Energy Trust of Oregon getting involved to help facilitate the program. I can envision power companies becoming involved too. If currently leaky houses are tighter then that is better for the long-term reduction of power that utilities have to produce.

    Plenty of older houses sell every day that were built before air sealing technology advanced to the point where it is today.

  7. User avater
    Harris Woodward | | #28

    Not regular construction, and not existing housing.:We did a MODULAR home. Our mostly finished 4-box 2-story started at 3.06ACH50, and ended at 1.08ACH50 170 minutes later. See attached Report. The curve indicates the constant buildup of sealant as the installation reached diminishing returns.

    Ironically, there was a missing piece of drywall discovered behind our 2nd floor air handler, and our AB tech explained that patching that would get us well below 1ACH. Which also tells me we would have been well below 3ACH from the gitgo - which is code required in Maryland.

    What we learned:
    1. This confirmed what we've known for years: modular/prefab construction is inherently tighter because modules (boxes) are built inside out in a controlled environment.
    2. Our 2-story on full basement and pulldown ladder to unfinished attic was pretty damned tight before AB, even before we patched a drywall hole in a mech. closet.
    3. New-to-modular contractors that forget to foam-seal the marriage floors/walls/ceilings (where boxes come together) before closing in can definitely save their skins with AeroBarrier.

  8. User avater
    Jeff_LDC | | #29

    The concept sounds appealing, however I have some concern about aerosolizing all these particles throughout the entire house. Obvy if the particles stick to the walls of the leaky spots, they will stick pretty much everywhere else too.

    My biggest concern though, is that of resilience. It stands to reason that the particles will build up only until the hole is sealed, but then no more. Thus, there will be "just enough" to fill the leaky spot, but maybe (probably?) not enough to last for the long haul (maybe a few years?) IMO... it's been too short a time for adequate "longevity" testing to have been performed, so we really have no way of knowing how long this air sealing option will last. Whereas we do know that if we liberally apply a flexible acrylic caulk, it will last many decades, barring any major movement of the building structure of course.

    If Aerobarrier is confident that their system will last for the long haul, I'd like to see a commitment to this end. I.e., some sort of written guarantee that they will come out for free and pressure test the house again after a decade, and if the product has not stood the test of time, they will visually inspect various areas that were treated with the customer to verify if they have degraded or separated, and if so, they will give a pro-rated portion of the initial costs back to the customer. If they are confident enough in their product, this should not be an issue to implement., especially at current costs.

    My final concerns are that of product waste, and potential air contamination of adjacent properties. These "particles" will be released en-masse, so there will potentially be a huge waste associated with this method (possibly part of the reason for such a high cost), and, these particles will filter through the air leaks contaminating the surrounding air to some extent... can't be good to breath this stuff in. That being said, unfortunately, there are always plenty of nuisance and/or toxic dusts floating around construction sites. But do we need more?

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