Fast, Reliable Blown-In Insulation Across San Antonio
Blown-in insulation in San Antonio typically runs $1.80-$3.40 per square foot of attic floor, with most complete attic jobs falling between $2,400 and $5,800 depending on existing conditions and R-value target. Our crews dispatch from the San Antonio office and usually book initial blower-door assessments within 48 hours. Call (830) 529-7780 for a written price before any work starts.
We’ve sealed and insulated over 9,000 homes since 2016, and the San Antonio market is where we see the most dramatic gap between what was built and what Climate Zone 2 actually demands. The 1950s-1970s slab-on-grade ranch homes that dominate neighborhoods like Castle Hills, Windcrest, and the areas around Lackland AFB were built with R-11 fiberglass batts or less - specifications that made sense on paper in 1962 but collapse under attic temperatures that hit 150-160°F in July and August. Our Blown-In Insulation team treats every job as a building-envelope repair, not a commodity install.
Why Topside Attic Insulation Boerne Is San Antonio’s Preferred Blown-In Insulation Company
San Antonio homeowners find us through referrals from energy auditors, real estate inspectors, and neighbors who’ve compared their CPS Energy bills before and after. Our reviews mention the same things repeatedly: the crew showed the blower-door numbers, explained what they meant, and left documentation that actually worked for the rebate submission.
We answer calls live, 24/7. No callback windows. When you schedule in San Antonio, you get a named technician and a text when they’re en route - that’s Haven Standard: Arrive on schedule.
Our dispatch operates from the San Antonio metro office, so crews know the local housing stock without GPS coaching. They recognize the 1958 ranch with the scuttle-hole access in the hallway closet, the 1925 Monte Vista Craftsman with balloon-frame walls and original knob-and-tube remnants, the 1972 Alamo Heights split-level with the cathedral ceiling that was never properly vented. This familiarity saves time and prevents the “we’ll have to come back with different equipment” conversation that out-of-town contractors seem to have a lot.
Our Blown-In Insulation Services in San Antonio
Blown-In Cellulose
Cellulose - ground and treated paper fiber - packs tighter than fiberglass and performs better at the temperature extremes San Antonio attics reach. We source GreenFiber cellulose for dense-pack wall work and loose-fill attic applications. In San Antonio’s Climate Zone 2, cellulose’s higher settled density slows convective looping through wall cavities, which matters when your attic is trying to turn your top floor into a convection oven six months a year. Typical installed cost for a full attic: $2.60-$4.20 per square foot.
Blown-In Fiberglass
We use Owens Corning and Johns Manville fiberglass for attic top-ups and full replacements where moisture history or homeowner preference points away from cellulose. Fiberglass doesn’t absorb humidity and recovers its full R-value faster if disturbed. In San Antonio’s semi-arid climate, that’s less of a concern than in Houston, but it matters in homes with roof leaks or bathroom venting issues. Full attic replacement with fiberglass to R-38: $2.20-$3.80 per square foot.
Dense-Pack Wall Insulation
This is our most called-for service in Monte Vista, Beacon Hill, and other inner-city neighborhoods with pre-1940 construction. Dense-pack means blowing cellulose into closed wall cavities at 3.5-4.0 pounds per cubic foot - dense enough to resist settling and slow air movement without removing drywall. Balloon-frame Craftsman homes have continuous wall cavities from foundation to attic; without dense-packing, those cavities act as chimneys that connect your crawl space to your roof. We document cavity fill with boroscope inspection photos. Dense-pack wall jobs in San Antonio typically range $3.20-$5.50 per square foot of wall area.
Blown-In Top-Up
Most common call we get: “My attic has some insulation, but it’s thin and patchy.” We never blow new material over an unsealed attic floor. Period. Our crew air-seals top plates, can lights, plumbing and electrical penetrations, and the chase around the flue first - then measures existing depth, calculates the fill needed to reach target R-value, and blows to spec. A typical San Antonio top-up from R-11 to R-38 runs $1,800-$3,400 for a 1,200-square-foot attic footprint. We photograph before, during, and after for your CPS Energy rebate documentation.
What happens when you call
- 1
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.
Trusted Brands We Service in San Antonio
We stock GreenFiber, Owens Corning, and Johns Manville materials locally - no special-order delays, no proprietary-product lock-in. Knauf fiberglass is available for jobs specifying higher recycled content or specific formaldehyde-free certifications. Our San Antonio warehouse carries the full range of densities and conditioned attic assemblies, so we don’t show up with the wrong blower door or insulation machine for your cavity size. Every bag is tracked to the job, and every install spec is written into your scope before the crew starts.
Common Blown-In Insulation Problems We See in San Antonio Homes
- Compressed legacy batts in 1950s-1970s ranch attics. Original R-11 fiberglass, often 3-4 inches thick where 6 inches was specified, has degraded to R-8 or less. Summer heat has baked the binder brittle; walking through the attic turns it to powder. We remove and start clean, or dense-pack over only after assessing compression and moisture history.
- Zero air sealing at top plates in Beacon Hill and Monte Vista homes. The gap between the wall top plate and drywall ceiling is rarely sealed in pre-1960 construction. Blown-in insulation covers it visually but doesn’t stop the air. A blue norther hits, and that convective loop you couldn’t feel in August becomes a draft you can’t ignore in January.
- Dense-pack failures from crews who don’t know balloon-frame construction. Hollow wall cavities with diagonal bracing create voids if the installer doesn’t map the framing first. We’ve opened walls where “dense-packed” cellulose had settled to 1.5 pounds per cubic foot - barely better than empty. Our crews use cavity-fill calculators and verify with boroscope.
- Attic access too small for proper work. Many slab-on-grade ranches have 14×22 scuttle holes or pull-down stairs with 7-foot clearance. We modify access points when needed, or use specialized hose equipment to reach distant corners. We document the access limitation and solution in your photo record.
Pricing for Blown-In Insulation in San Antonio, TX
Here’s what blown-in insulation costs in the San Antonio market, based on jobs we’ve completed in the last 24 months:
| Service | Typical Range | What Affects Price |
|---|---|---|
| Attic top-up (R-11 to R-38) | $1,800 - $3,400 | Existing depth, access difficulty, air-sealing extent |
| Full attic replacement to R-38 | $2,800 - $5,200 | Removal labor, decking condition, ventilation fixes |
| Full attic replacement to R-49 | $3,400 - $6,200 | Higher fill volume, access constraints |
| Dense-pack wall insulation | $3.20 - $5.50/sq ft wall | Cavity depth, framing complexity, interior or exterior access |
| Air sealing only (before insulation) | $800 - $1,800 | Attic size, can light count, chase complexity |
These ranges assume standard attic access and no active roof leaks or rodent damage requiring remediation first. Every job gets a written price before work starts - Haven Standard Clause 1 - and we offer a Free Second Opinion on any competing written estimate. Call (830) 529-7780 to schedule assessment.
We Also Serve Cities Near San Antonio
Our crews work daily in San Antonio and the surrounding communities: Converse, Universal City, Schertz, and Helotes. Same written-price guarantee, same blower-door documentation, same live-answer dispatch.
Serving San Antonio, TX - Our Local Coverage Area
We’re based in the San Antonio area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
FAQs - Blown-In Insulation in San Antonio
CPS Energy requires pre-installation photos, post-installation photos, and documented R-value calculations submitted in a specific format that out-of-town contractors routinely get wrong. We build the documentation into every job - photos of existing depth, air-sealing completion, finished depth with ruler visible, and blower-door results if air sealing was performed. The rebate typically runs $0.10-$0.30 per square foot depending on R-value improvement and income qualifications. Call (830) 529-7780 and we’ll walk you through current CPS rebate tiers before you commit.
No - not without inspecting what’s there first. Fifty-year-old batts in San Antonio attics are often compressed to R-8 or less, contaminated with rodent activity, or moisture-stained from roof leaks. Blowing over compromised material traps problems and voids manufacturer warranties. Our crew removes degraded material, air-seals the attic floor, then blows to spec. You’ll get photos of what we found and what we did. Written price before any work starts.
Monte Vista’s 1920s balloon-frame homes have continuous wall cavities from foundation to attic with no top plates to block air movement. Without dense-packing, those cavities function as chimneys connecting conditioned space to the attic. Dense-pack cellulose at 3.5+ pounds per cubic foot fills the cavity, bridges around diagonal bracing, and slows both convective heat gain and the cold drafts that blue northers push through every gap. We verify fill density with boroscope inspection. Call (830) 529-7780 for a wall-cavity assessment.
Current IECC code for Climate Zone 2 calls for R-38 minimum in vented attics; we typically specify R-38 to R-49 for San Antonio retrofits given the extreme attic temperatures. The difference in material cost is usually $400-$700 for a typical ranch, and the incremental cooling-load reduction pays back in 3-5 years at CPS Energy rates. We calculate payback explicitly in your written scope so you can decide with numbers, not pressure.
We create code-compliant access - typically a framed scuttle hole with trim and weatherstripping, or an insulated pull-down stair assembly if ceiling height allows. The access modification is itemized in your written price, not sprung as a surprise. Some ranches with cathedral ceilings or conditioned attic spaces need different approaches; we assess and specify in the initial scope. Every option is photographed, priced, and documented before any insulation moves.
Written by Wes Okafor, Owner at Topside Attic Insulation Boerne, serving San Antonio since 2016.