Trusted Attic Air Sealing for Boerne Homeowners
Attic Air Sealing in Boerne typically costs $1,200-$3,800 for a complete job, and most homes we seal show a 30-50% reduction in air leakage on the blower-door test. We’re Topside Attic Insulation Boerne, and we’ve been sealing attics across Kendall County and the Hill Country since 2016. Our crews complete most attic air sealing projects in a single day, and we publish before-and-after blower-door numbers on every job so you can verify the result in writing. Call (830) 529-7780 - a live person answers 24/7, and we’ll have a technician to your Boerne home with a written price before any work starts.
The Hill Country’s temperature swings are hard on houses. In summer, your attic hits 140°F while your living room sits at 72°F. In winter, hard freezes roll through Boerne from the northwest, and every crack in your ceiling plane lets heated air escape into that ventilated attic space. We’ve sealed and insulated over 9,000 homes since 2016, and the pattern we see in Boerne is consistent: builders insulated first, sealed never. The fiberglass or cellulose went in over gaps, bypasses, and unsealed penetrations that have been leaking conditioned air since the day the house was finished. We’re not here to add more insulation on top of that mess. We seal first. Then we talk about insulation.
What Our Attic Air Sealing Service Includes
Attic Floor Air Sealing
The attic floor is your home’s thermal boundary, and in most Boerne homes built between 1995 and 2020, it’s full of holes. We seal the drywall-to-top-plate joint, plumbing and electrical penetrations, and any gaps around chimneys or framing members using polyurethane foam, acoustical sealant, or fire-rated caulk depending on the application. A typical 2,400-square-foot home in Boerne leaks enough air through the attic floor to equal a 2×2 foot hole in the ceiling. We find every bypass with a blower-door test and infrared camera, then seal them methodically. No insulation touches that attic floor until the sealing is complete and verified.

Top Plate & Penetration Sealing
Top plates are the horizontal framing members where interior walls meet the ceiling. Every one of them has a gap where the drywall doesn’t quite meet the framing, and that gap runs the full length of every wall in your house. In Boerne’s older homes near Main Street and in newer subdivisions like Herff Ranch alike, these top plates are unsealed. We pull back existing insulation, run a continuous bead of sealant along every top plate, and seal every wire, pipe, and duct penetration that passes through it. This is tedious work that takes time. We don’t rush it. The blower-door test at the end tells us if we got it right.

Can Light & Duct Boot Sealing
Recessed can lights are among the worst offenders in Boerne attics. The old-style non-IC fixtures create a direct pathway from your conditioned space into the attic, and even IC-rated fixtures rarely seal airtight. We install preformed fire-rated covers over can lights, then seal the edges with high-temperature caulk. Duct boots - the sheet metal transitions where your HVAC ducts enter the ceiling - are another chronic leak point. The flex duct collar often pulls away from the boot, or the boot itself was never sealed to the drywall. We reattach, support, and seal every boot with mastic or foil tape rated for duct applications. In Boerne’s cooling-dominated climate, these leaks cost you more in summer than winter, but they cost you year-round.

Attic Hatch Sealing
The attic hatch is a hole in your ceiling by design, and most are built without weatherstripping, without insulation on the back, and without any attempt at airtightness. We build up insulated, gasketed hatch covers that seal against a clean stop when closed. For pull-down stairs, we install a sealed, insulated enclosure above the frame. This is especially important in Boerne homes with attic access in conditioned hallways, where the hatch sits in the path of your most-used living space. We document the before-and-after with photos, and the blower-door test captures the improvement.

What happens when you call
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A real person answersNo phone trees - you reach a local pro.
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You get an upfront price rangeHonest numbers before anyone is dispatched.
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A background-checked tech heads outLicensed & insured, dispatched right away.
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You approve before work beginsNothing starts until you say go.
Brands We Service for Attic Air Sealing

We’ve worked with Owens Corning air-sealing products since our first year in business, and we know their Foamular rigid foam and ProPink sealants well enough to specify them by application without looking at the catalog. For homes in Boerne where we’re sealing around complex penetrations or need a vapor-closed assembly, Icynene’s water-blown spray foam gives us the control we need for thin, precise applications. And when we’re topping off a sealed attic with blown cellulose, GreenFiber’s stabilized product packs well around our sealed penetrations without settling away from the work we just finished. We don’t push proprietary systems or lock you into a single manufacturer. We pick the material that matches the detail.
Whether your Boerne home has Demilec open-cell foam from a previous contractor’s partial job, Johns Manville batts that need to be moved and replaced, or any other combination of materials in the attic, we can work with it. Our inventory includes Knauf and CertainTeed products as well, and our technicians are trained to identify what they’re looking at before they disturb it. The point isn’t the brand on the bag. The point is a sealed ceiling plane that holds up under a blower-door test.
Signs You Need Attic Air Sealing Right Now
- Your upstairs rooms are 8-12°F warmer than downstairs in summer. This isn’t normal. In a sealed, properly insulated Boerne home, the temperature difference between floors should be 3-5°F at most. Hot upstairs rooms mean conditioned air is leaking out through the attic floor faster than your HVAC can replace it, and the stack effect is pulling superheated attic air down through light fixtures and outlets.
- You can see dirty insulation in your attic. Fiberglass or cellulose that looks gray, brown, or streaked has been filtering air passing through it. Clean insulation is a uniform color. Dirty insulation is a map of every leak path in your ceiling. We’ve shown homeowners in Boerne neighborhoods like Menger Springs and Balcones Creek their own attic photos, and the reaction is always the same: they didn’t know their ceiling had that many holes.
- Your energy bills spike every July and August. Boerne’s cooling season runs long, and an unsealed attic forces your air conditioner to work overtime. If your summer electric bills are 40% higher than your spring bills and your neighbors’ homes aren’t, the building envelope is the place to look. We’ve seen $200-$400 monthly reductions after sealing and re-insulating attics in 2,500-square-foot homes.
- You feel drafts from light fixtures or outlets in winter. Those aren’t ghosts. Cold air falls from your ventilated attic through penetrations in the ceiling plane, and the path of least resistance often ends at a can light or switch box. In Boerne’s occasional hard freeze events, these drafts make rooms uncomfortable even when the thermostat reads 70°F. Sealing the attic floor stops the air movement at its source.
- Your HVAC runs constantly but never catches up. An air conditioner that cycles on for 45 minutes, off for 5, then on again is fighting a losing battle against air leakage. The equipment is sized correctly for your home’s load, but the load calculation assumed a sealed building envelope. Yours isn’t. Before you replace a “failing” unit, have the attic tested. We’ve saved Boerne homeowners thousands by sealing instead of upsizing.
Our Attic Air Sealing Process - Step by Step

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Schedule and arrival. You call (830) 529-7780, a live person picks up, and we book a time that works. Under Haven Standard: Arrive on schedule, you get a named technician and a text when they are on the way. Our technician arrives in a marked vehicle, uniformed, background-checked, with photo ID.
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Blower-door test and infrared scan. We install a blower door - a calibrated fan in a temporary frame that depressurizes your home to measure air leakage in CFM50, cubic feet per minute at 50 Pascals of pressure. While the fan runs, we use a thermal imaging camera to map the leak paths through your ceiling. You see the images in real time. This baseline number, typically 3,500-6,000 CFM50 for an unsealed Boerne home of 2,000-3,000 square feet, is your before.
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Written price and scope. Before anyone enters the attic, we deliver a written price, a written scope of work, and a written warranty. Haven Standard Clause 1: flat price, written scope, written warranty before anyone lifts a tool. No surprises, no “we found more once we got up there” add-ons. If you have a competing estimate, bring it - our Free Second Opinion means we’ll read it with you and explain where the scope differs.
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Air sealing execution. We move existing insulation aside, seal every penetration and bypass we documented, then replace the insulation undisturbed. We work methodically across the attic floor, photographing every stage. For Attic Air Sealing in Boerne, our crews know the local building practices: the unsealed top plates in 2000s-era production homes, the can-light proliferation in 2015-2020 builds, the duct boots that never got mastic in any decade.
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Verification and documentation. We run the blower-door test again. The after number goes on your invoice, along with the before, the photo record, and the technician’s notes. You get a Documented Photo Record on every visit, included, not available on request. If the numbers don’t meet our standard for the scope, we keep sealing until they do. The 365-Day Done Right Promise applies from that moment.
How Much Does Attic Air Sealing Cost in Boerne?
Most complete attic air sealing jobs in Boerne run $1,200-$3,800, with the majority of single-family homes falling in the $1,800-$2,800 range. A focused job - sealing can lights and duct boots in a 1,800-square-foot home, for example - might land at $900-$1,400. A comprehensive seal of a 4,000-square-foot home with multiple attic planes, complex framing, and extensive penetration work can reach $4,500-$5,500.
What moves the number: square footage of attic floor, accessibility (truss height, existing insulation depth, obstructions), number and type of penetrations (can lights, chimneys, ductwork), and whether we’re working around existing insulation or removing it first. Homes in Boerne’s newer developments like Esperanza or Kendall Creek often have straightforward truss attics with good access. Homes in the historic district near Main Street may have balloon framing, multiple small attic compartments, or knob-and-tube wiring that requires careful coordination.
We don’t quote by phone without seeing the space. What we do promise: the price we write is the price you pay. No change orders, no “while we were up there” surprises. Every estimate includes the blower-door test, the sealing work, the verification test, and the photo documentation. If another contractor in Boerne gave you a written estimate, bring it. Our Free Second Opinion is exactly what it sounds like - we’ll sit down with you and compare scope line by line.
Attic Air Sealing Near Boerne - Our Service Area

We seal attics from our Boerne base across the Hill Country and northern San Antonio metro. Typical drive times: Attic Air Sealing in Fair Oaks Ranch is 15 minutes south on Boerne Stage Road. Attic Air Sealing in Scenic Oaks is 20 minutes southeast. We regularly work in Helotes, Timberwood Park, Lakehills, Bulverde, Leon Valley, Castle Hills, and Alamo Heights. San Antonio proper and Terrell Hills are within our standard service radius. Most attic air sealing projects in the Boerne area are scheduled within 3-5 business days, with same-day emergency response available for homes where air leakage has created an active moisture or safety issue.
Serving Boerne, TX - Our Local Coverage Area
We’re based in the Boerne area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
Frequently Asked Questions - Attic Air Sealing in Boerne

Attic air sealing is the process of closing gaps, cracks, and penetrations in your ceiling plane to stop conditioned air from escaping into your ventilated attic. We use foam, caulk, and specialized gaskets to seal the attic floor, top plates, can lights, duct boots, and attic hatch. In Boerne’s climate, this single measure often reduces heating and cooling loads more than adding insulation alone.
Most attic air sealing jobs in Boerne are completed in one day, typically 4-8 hours of crew time depending on attic size and complexity. A focused job - can lights and duct boots only - might take 3 hours. A comprehensive seal with multiple attic planes, chimney work, and hatch rebuilding can extend to two days. We tell you the expected duration in your written scope before we start.
Attic Air Sealing - Bulverde and Boerne projects typically cost $1,200-$3,800 for a complete job, with most homes falling between $1,800-$2,800. The price depends on attic square footage, accessibility, number of penetrations, and whether existing insulation needs to be moved or removed. Call (830) 529-7780 for a free estimate with a written price before any work starts.
Yes. We’ve worked with Owens Corning air-sealing products since 2016 and use Icynene spray foam for specialized sealing applications around complex penetrations. We also service homes with Demilec, GreenFiber, Johns Manville, Knauf, CertainTeed, and Rockwool materials. We don’t require you to use a specific brand, and we don’t claim exclusive status with any manufacturer.
Yes. A live person answers our phones 24/7, and we prioritize calls where air leakage has created an active problem: moisture accumulation in the attic, ice dam conditions during rare hard freezes, or visible mold growth traced to conditioned air escaping into cold spaces. For standard scheduling, most Boerne-area homes are booked within 3-5 business days.
Every attic air sealing job is backed by our 365-Day Done Right Promise - if it’s not done right, we make it right. The specific warranty terms are written and delivered before work begins, per Haven Standard Clause 1. The warranty covers both materials and workmanship, and it’s transferable if you sell your home within the coverage period.
Clear a path to your attic access and remove any stored items within 3 feet of the hatch. We need working electrical outlets for our blower-door fan and lighting. If you have pets, secure them in a separate room during the blower-door test - the pressure change can startle animals, and doors will be opened repeatedly. We’ll handle everything else, including moving and replacing insulation. Call (830) 529-7780 to schedule, and we’ll send a text when your technician is on the way.
Schedule Your Attic Air Sealing Service in Boerne Today
Call (830) 529-7780 now. A live person answers 24/7, and we’ll schedule your free estimate with a written price before any work starts. Every job includes a blower-door test, documented photo record, and our 365-Day Done Right Promise. Serving Boerne, Fair Oaks Ranch, Scenic Oaks, our Attic Air Sealing in Helotes, and the full Hill Country area since 2016.
Written by Wes Okafor, Owner at Topside Attic Insulation Boerne, serving Boerne since 2016.