Short answer
AeroBarrier seals the building envelope from the inside. A blower door pressurizes the closed-up house, and a computer-controlled system fills it with a water-based sealant mist. Air escaping through the gaps carries the particles to the edges of each leak, where they build up until the gap closes. The blower door stays on the whole time, so the leakage reading drops live and I stop when the house reaches your target ACH50. A typical single-family home is one day on site.
Why it works differently from hand sealing
Hand sealing finds the leaks you can see. Caulk, tape, spray foam and gaskets are all good tools, and you still need them for the big holes. The problem is the leakage you cannot see: the hundreds of small gaps at plates, rim joists, penetrations, window rough openings and drywall edges that add up to most of a failed number. Nobody can find all of them by eye, and you do not learn what you missed until the blower-door test.
An aerosol seal flips that. The pressure difference drives the sealant to the leaks, so it reaches gaps nobody knew were there, and the blower door measures the result while it happens. You are not sealing and hoping. You are sealing to a number.
When to book it
The sealing window is a range, not a single day. These are the conditions I need before I can seal:
- Windows and exterior doors installed. The house has to be closed up so it can be put under pressure. This is the one people miss.
- Rough-ins done and inspected. Electrical, plumbing and HVAC, so nobody drills back through the seal afterwards.
- Big holes closed. The aerosol is built for small gaps. Open chases, unsealed duct boots, missing sheathing and large penetrations get closed by hand first, and I will walk the house and flag them when I scope the job.
The best day is after insulation, before drywall. Nothing is covering the gaps, so the sealant gets straight to them and the day goes quicker. Drywall up, taped and even primed still works; it takes a little longer because the board is in the way. What closes the window is finished materials: flooring, cabinets and trim. If those are booked, that date is the one that matters.
Tip for supers: book the seal around your mid-construction blower-door test with your energy advisor. Testing before and after the seal gives you an independent number on both sides of it. See Step Code airtightness for how the testing fits together.
What happens on seal day
- Walk-through and prep. I confirm the house is closed up, check for open holes that need hand sealing first, and set up the equipment.
- Masking. Anything the mist should not land on gets covered: window and door faces, finished horizontal surfaces, fixtures, and any openings that are meant to stay open (vents, drains, mechanical penetrations that get sealed separately). More finishes in the house means more masking.
- Baseline reading. The blower door brings the house to test pressure and records where the leakage starts.
- The seal. The system atomizes the sealant and fills the house while the blower door holds the pressure. The software tracks the leakage reading the whole time, so you watch the number fall.
- Stop at the target. I run it until the house reaches the target we agreed, then ventilate, unmask and clean up.
- Final reading and report. A closing blower-door reading and an Airtightness Verification Report for your file, showing where the house started and where it finished.
Other trades stay out of the house while the seal runs. A typical single-family home is one day on site including setup and cleanup.
When the seal stops, the house is ventilated before anyone goes back in. Trades are usually back in the same day, and by the next morning at the latest.
What you get at the end
You get an Airtightness Verification Report documenting the readings taken on site during the seal: the starting leakage, the finished leakage, and the target. It is a record of the seal, not a code compliance certificate. Code compliance airtightness testing is done by your project's energy advisor, and their test is the number that goes into your Step Code file. The point of my report is that you already know the answer before they arrive.
What it does not do
- It does not replace your air barrier details, firestopping, or the hand sealing of large openings. It finishes the job those start.
- It does not replace ventilation. A tight house needs mechanical ventilation (an HRV or ERV) sized by your designer. Build tight, ventilate right.
- It is not insulation. It closes air leakage paths; it does not change R-value.
- It cannot be run once flooring, cabinets and trim are in, because masking finished interiors at that point is not practical.
If an aerosol seal is not the right call for your build, I will tell you before you spend anything.
Written by Sebastian Motora, owner-operator. Last reviewed October 7, 2026.