Your commercial building didn’t hit its air tightness target, and now the whole team wants answers. That’s a stressful spot, especially when closeout is close and every day counts. The good news is a failed test isn’t the end of the road. It’s a signal that points you toward a fix.
This blog will walk you through an ASTM E779 test failure step by step. You’ll learn what the threshold means, where leaks usually hide, how remediation works, and how retesting fits your commissioning timeline. Keep reading so you know exactly what to expect and how to protect your schedule.
A failure means your building let in more air than the project spec allows. Testing crews run a blower door to change the air pressure inside the building, then measure how much air sneaks through the building envelope. The result gets compared against your target.
Most commercial projects follow the ACH75 commercial requirement, which reports air changes per hour at 75 pascals. Your air leakage test threshold comes from your energy code, ASHRAE 90.1, or the project’s own spec. When your number lands above that limit, you’ve missed the mark. It’s a clear, measurable result, not a judgment call, which makes the next steps easier to plan.
When a commercial blower door test fails, the diagnosis starts quickly. Crews use smoke and infrared imaging to trace air pathways while the building stays under pressure. The leaks tend to cluster in the same trouble spots.
Watch the roof-to-wall transitions, penetrations for pipes and conduit, expansion joints, and door and window frames. Curtain wall connections and unsealed deck edges leak too. These gaps add up quickly across a large envelope. Because your code requirement ties directly to the test result, pinpointing each source matters. A clear map of the leaks tells your team what to seal and where, so no one wastes time guessing.
Once you know where the air escapes, building air barrier remediation gets to work. Crews seal gaps with the right products for each spot, like fluid-applied membranes, sealants, gaskets, and proper flashing details.
The fix depends on when you catch the problem. Pre-drywall leaks are cheap and quick to close. Leaks found after finishes go up cost more and take longer. That’s why early testing pays off. A tight, well-documented remediation plan keeps the work focused and your budget in check.
After the sealing wraps up, a commercial air leakage retest confirms the building now meets its target. Here’s how that sequence usually runs within a Cx and closeout timeline.
Air Tight Solutions was born from hands-on work on real construction sites. We saw how energy code compliance frustrated builders and slowed projects down, so we built a company that makes testing simple, accurate, and reliable. Our certified team uses industry-leading equipment and deep knowledge of standards to help you hit your numbers and stay on schedule.
We work side by side with GCs, owners, and commissioning teams across the Southeast. From testing to clear reporting to retest support, we guide you through every step with honest advice and precise results. When your project’s envelope needs a partner who knows the protocol inside and out, we’re ready.
No. Failing points to specific leaks you can seal. Most fixes are targeted repairs rather than major rework, especially when you catch issues early.
Often the next day, once sealing wraps up. We coordinate around your trades so the building stays ready for an accurate measurement.
Your energy code, ASHRAE 90.1, or the project spec sets it. We test your building against that exact number.
Yes, and we recommend it. Pre-drywall testing catches leaks while they’re cheap and easy to seal, saving time and money.
Yes. We deliver clean, formatted reports ready for your commissioning agent and code official to review and close out.