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Serving Reno, NV and surrounding areas(775) 491-3183
Insulation slows heat transfer through the materials, but air leaks bypass it entirely. A blower door test locates the specific gaps and bypasses driving your highest energy losses, and systematic sealing from attic to foundation closes them for good.
Air sealing in Reno identifies and closes the uncontrolled gaps in your building envelope — attic bypasses, band joists, plumbing penetrations, electrical boxes — that let conditioned air out and outdoor air in; most whole-home jobs are scheduled within a week and completed in a single day.
Older Reno homes, particularly the pre-1980 houses concentrated in Midtown, Old Southwest, and the neighborhoods around the University of Nevada campus, routinely test at 8 to 10 air changes per hour at 50 Pascals — two to three times the 3 ACH50 maximum required by Nevada's current energy code for new construction. That leakage rate means the home is effectively replacing its entire air volume multiple times per hour with outside air, regardless of how much insulation is in the attic. Adding more insulation on top of that level of leakage delivers a fraction of its expected benefit.
Air sealing is most effective when paired with home insulation improvements, because sealing controls the air movement that insulation cannot stop. Homes that only need targeted attic work can start with attic air sealing, which addresses the highest-pressure leakage zone in most Reno homes without a full envelope diagnostic. The right scope for your home depends on what the blower door shows.
Electrical boxes on exterior walls are rarely sealed to the framing and create a direct pathway for cold outside air. In a Reno home during a Washoe Zephyr wind event, a single unsealed outlet box can drive a noticeable draft into the room. These are among the easiest and highest-impact fixes in a whole-home sealing job.
Floors that stay cold no matter how high the thermostat runs usually point to an unsealed band joist — the framing where the floor system meets the foundation wall. This is one of the largest air leakage zones in a typical Reno home and is often left completely open on homes built before the 1990s.
Insulation slows conductive heat transfer, but a home can be well-insulated and still lose enormous amounts of energy to air leakage. If you have upgraded attic insulation and your NV Energy bills have not improved proportionally, air sealing the bypasses and penetrations that insulation does not cover is typically the next highest-return step.
Smoke entering a closed home arrives through the same gaps that drive energy loss the rest of the year. Reno's wildfire smoke events are becoming longer and more intense, and a professionally sealed building envelope is the most durable way to reduce indoor particulate load — more effective long-term than portable air filtration alone.
Every air sealing project starts with a blower door test. A calibrated fan is mounted in an exterior doorway, the house is depressurized to 50 Pascals below outdoor pressure, and the total leakage rate is measured in ACH50. That number tells us how leaky the home is. A smoke pencil or thermal camera reveals where the leaks are. Without this step, sealing work is directional at best. The pre-work test also establishes the baseline for post-work verification — the second test that confirms the improvement was real and documents the result for permit compliance or tax credit purposes.
The sealing sequence follows the physics of how air actually moves. The attic plane comes first because stack-effect pressure drives the most leakage through ceiling penetrations, top plates, recessed light fixture boxes, duct chases, and attic hatch perimeters. Contractors move systematically across every bay, using low-expansion spray foam for gaps between a half inch and three inches, caulk for narrower cracks, and rigid blocking combined with fire-rated caulk around flue and chimney penetrations where foam is not permitted. The band joist — where the floor framing meets the foundation — is typically the second-largest leakage zone and is sealed with foam board and spray foam in a single pass. The U.S. Department of Energy's air sealing guide identifies these as the highest-priority locations in any residential sealing scope.
Before any sealing begins, combustion appliances are tested under worst-case depressurization conditions. This step is required under DOE Standard Work Specifications and by Nevada's Weatherization Assistance Program — it is not optional. If a gas furnace, water heater, or fireplace shows backdrafting risk at the pre-work test, that issue is addressed before sealant is applied, because tightening the envelope without resolving a combustion safety problem creates a carbon monoxide hazard. Post-work, if the home tests below approximately 5 ACH50, ventilation adequacy is confirmed against ASHRAE Standard 62.2 minimums and supplemental mechanical ventilation is recommended where needed. The Building Performance Institute (BPI) Building Analyst credential is the recognized national benchmark for contractors performing this full diagnostic and sealing scope — the training standard our technicians follow.
Best for older Reno homes with high ACH50 readings — blower door test, attic-to-foundation sealing, combustion safety, and post-work verification in a single scope.
Best for builders needing documented 3 ACH50 compliance under Nevada's energy code — sealing during framing, followed by a verified blower door report for the inspector.
Best for homes where the attic is the primary leakage zone — ceiling penetrations, top plates, duct chases, and hatch perimeters sealed without a full envelope scope.
Best for homes with cold floors or high foundation-level infiltration — foam board plus spray foam at the rim joist, with optional crawl space floor sealing.
Reno's 4,500-foot elevation and semi-arid continental climate create conditions that make air leakage more costly than in lower-elevation or warmer Nevada cities. The daily temperature swing of 30 to 45 degrees — common across all four seasons — intensifies the stack effect that drives infiltration. Cold outside air continuously pushes in at the foundation level while warm conditioned air escapes through the attic. The Washoe Zephyr wind events, which can sustain 40 to 60 mph gusts across the Truckee Meadows, create additional pressure differentials that accelerate this exchange through any unsealed gap.
Reno's growing wildfire smoke seasons have added a second reason to take air sealing seriously. Fine particulate matter from regional fires enters through the same gaps that drive energy loss, and the health impact of elevated indoor PM2.5 during Red AQI days is real. A tightly sealed building envelope reduces the indoor particle load more durably than portable air filtration, which has to cycle contaminated air continuously to maintain air quality.
The communities northwest of Reno see some of the highest pre-retrofit leakage rates in the metro because of the age and construction methods of their housing stock. Cold Springs and Lemmon Valley homeowners regularly contact us after NV Energy bills spike in the first winter after moving in. To the east, Sparks has a mix of newer subdivisions that require new-construction blower door compliance and older neighborhoods where retrofit sealing delivers the largest energy returns.
Contact Reno Insulation by phone or the online form. We respond within 1 business day to schedule a diagnostic visit at a time that fits your calendar.
A technician installs the blower door, depressurizes the home, and measures the current ACH50 leakage rate. We also test every gas combustion appliance under worst-case conditions before any sealing begins — this step is required under DOE Standard Work Specifications and protects your family from backdrafting risk.
Work proceeds from the attic plane downward — top plates, recessed light fixtures, duct chases, attic hatch perimeters — then moves to the band joist and crawl space. Caulk, low-expansion foam, rigid blocking, and weatherstripping are selected based on gap size and substrate. You do not need to be home for most of this phase.
A second blower door test confirms the improvement and documents the ACH50 result. For new construction, this report satisfies the Washoe County building inspector's code compliance requirement. For existing homes, it supports your Inflation Reduction Act tax credit claim.
The blower door test takes about an hour and gives you a concrete ACH50 number. No guessing, no obligation to proceed until you see the written estimate.
(775) 491-3183Every job starts with a calibrated pre-work test that identifies where air is actually escaping, not where it might be. That data directs the sealant crew to the highest-impact locations first, so you pay for work that measurably reduces your ACH50 reading.
We run a worst-case depressurization combustion safety test before and after sealing on every home with a gas appliance — following the same protocol required by Nevada's Weatherization Assistance Program. If a furnace or water heater shows backdrafting risk, we address it before the job closes, not after.
For new construction in Reno and Washoe County, we deliver a signed blower door test report meeting the 2021 IECC Climate Zone 5 maximum, giving your building inspector the verification needed to issue a final certificate of occupancy.
We have worked in pre-1980 homes throughout Midtown and Old Southwest Reno, where older combustion appliances and knob-and-tube wiring passages create air sealing challenges that require a different approach than a typical newer-construction job.
Diagnostics-first sealing, combustion safety, code-compliant documentation, and local experience with Reno's specific housing stock — these are the elements that separate a job that genuinely reduces your ACH50 from one that applies sealant and calls it done. The blower door numbers before and after the work are the only objective measure of whether air sealing actually worked.
Focused sealing of the attic plane — top plates, recessed fixtures, duct chases, and hatch perimeters — where stack-effect pressure drives the most leakage in a typical Reno home.
Learn moreWhole-home insulation assessment covering attic, walls, rim joist, and crawl space — typically the next step once air sealing has closed the infiltration pathways.
Learn moreReno temperatures drop fast in October. Knowing your ACH50 now means you can seal before the cold sets in — not after your first high gas bill of the year.