Fast, Reliable Attic Insulation Across San Antonio
Attic insulation in San Antonio is the highest-ROI upgrade most homeowners can make, especially in the 1970s through 2000s production homes that dominate the north and west sides. A typical full attic insulation project in San Antonio runs $1,800 to $4,200 for a 1,800 to 2,400 square foot single-story home, with blown-in fiberglass or cellulose at the lower end and spray foam or radiant barrier packages higher. We serve every corner of San Antonio, from King William to Stone Oak, with crews dispatched from our local San Antonio office. When you call (903) 437-9164, a live person answers and schedules your written estimate, usually within 24 to 48 hours.
Why Thistledown Insulation San Antonio Is San Antonio’s Preferred Attic Insulation Company
We’re a Cedarwell-family company, founded in 2003, and we’ve spent two decades learning exactly how San Antonio attics behave under 100°F summers and muggy Gulf-coast humidity. Our crews arrive in uniform, background-checked, and wearing shoe covers from the moment they step through your front door. Drop cloths go down across the hallway and up to the attic hatch, so your floors look the same when we leave as they did when we arrived. We photograph the clean-up before we pull away, and we hand you that photo along with your written job summary.
San Antonio homeowners tell us the same thing over and over: they called other insulation companies and got a vague range and a week of waiting. With Thistledown, you get a written price before any work starts. Neil Barron leads our San Antonio operation, and he holds every job to the Cedarwell Care Promise: clean up like it’s our own home, ask before we move or touch anything, respect the family’s time and quiet hours, and explain the price before the work. The 365-Day Done Right Promise backs every install, no debate, no fine print.
Our Attic Insulation team has worked in bungalows in Monte Vista where the attic access is a 20-inch square in a hallway ceiling, and in sprawling two-story brick veneer homes off Loop 1604 where the attic is big enough to stand up in. That range matters because the right product depends on the house. We carry Owens Corning, Johns Manville, Knauf, Rockwool, CertainTeed, Icynene, Demilec, and GreenFiber, which means we’re not pushing one brand onto every roof. We match the product to your attic and your family, including pet-safe options where a choice exists, so the dog can stay home during the job.
Blown In Insulation in San Antonio
Blown In Insulation is the workhorse upgrade for San Antonio’s older production homes and detached workshops, where existing batt insulation has compressed or settled and left bare spots over rooms that bake in the afternoon sun. The job involves running a hose from a truck-mounted blower up to the attic, air-sealing the top plates and can lights, and laying down an even blanket of loose-fill fiberglass or cellulose to a depth that hits your target R-value. For a typical 1,500 to 2,000 square foot attic in San Antonio, blown-in insulation runs $1,500 to $3,300 depending on depth and product. We use Owens Corning AttiCat fiberglass on most San Antonio jobs because it holds its loft in high heat and won’t settle the way older cellulose can.
What Happens During the Install
We arrive with the blower truck, run the hose through a window or up the attic hatch, and two technicians work from inside the attic. One runs the hose; the other checks depth with a ruler every few feet so you get the R-value you paid for, not a guess. The whole job takes three to five hours for a standard ranch home.
When San Antonio Homes Need It Most
Homes built before 2000 in neighborhoods like Oak Hills and Churchill Estates often have only R-11 batts that have flattened under decades of heat. Upstairs bedrooms run 10 to 15°F hotter than downstairs until we blow in a fresh R-38 to R-49 layer. The difference shows up the same week we finish.
Insulation Contractors in San Antonio
Insulation Contractors in San Antonio are not all the same, and the ones worth hiring show you exactly what they’ll do before they start. We’re the crew that puts the number in writing first. A typical attic top-up in a 1980s San Antonio ranch runs $1,200 to $2,500; a full removal and replacement runs $2,800 to $5,000. Our role as your insulation contractor includes inspecting the attic, identifying settled areas and air leaks, recommending the right product and depth, and installing it cleanly in one trip.
Working With Thistledown
We show up when we say we will. We lay drop cloths, we wear shoe covers, and we keep the noise down if your kids are napping. At the end of the job, you get a photo of the cleaned-up attic and hallway before our van leaves your street.
Detached Workshops and Outbuildings
San Antonio acreage properties often have detached workshops, garages, or bonus rooms that were never properly insulated. We treat those as their own job: air-seal the top plates, insulate the attic and walls where accessible, and address the roll-up door’s air seal as part of the thermal boundary. One trip, done right.
Trusted Brands We Service in San Antonio
We install and service products from Owens Corning, Icynene, and GreenFiber across San Antonio, and we stock the common materials locally so we’re not waiting on a truck from Dallas or Houston. If your attic has old Owens Corning batts that have settled, we can top them up with the same brand or switch you to GreenFiber cellulose where it makes sense. For closed-cell spray foam in humid San Antonio attics, we use Icynene and Demilec products applied by our trained crew. The right product for the right attic, not whatever is on sale this month.
Common Attic Insulation Problems We See in San Antonio Homes
- Compressed R-11 batts in 1970s production homes: In neighborhoods like Oak Hills and Churchill Estates, the original fiberglass batts have flattened from decades of heat cycling. Upstairs bedrooms run 10 to 15°F hotter than downstairs until the attic is topped up to R-38 or higher.
- Settled blown-in cellulose leaving bare spots over detached additions: San Antonio’s high attic heat causes older cellulose to settle unevenly, especially over workshop additions where the original install was thin. Those bare spots turn into hot zones directly over the room you’re trying to cool.
- Warped overhead attic access doors on acreage outbuildings: Humidity in San Antonio makes the plywood or drywall hatch doors on detached workshops and garages swell and warp, breaking the air seal. Hot, moist air pours into the insulated space and undoes the work the insulation is trying to do.
- Radiant barrier trapping condensation in metal-roofed workshops: Stapling radiant barrier directly to the underside of rafters in a metal-roofed outbuilding can trap moisture against the roof deck, promoting rust and mold on the purlins. This is a San Antonio-specific failure we see on rural properties around Cibolo and Floresville.
Pricing for Attic Insulation in San Antonio, TX
A typical attic insulation project in San Antonio runs $1,800 to $4,200 for a standard 1,800 to 2,400 square foot home. Attic top-ups run $1,200 to $2,500. Full removal and replacement runs $2,800 to $5,000. Detached workshops and acreage outbuildings run $1,500 to $3,800 depending on size and whether the roll-up door needs air sealing. What moves the number is attic size, the depth of insulation you want, whether old insulation needs removal, and whether you’re adding radiant barrier. You’ll have your exact written number before we touch a rafter.
San Antonio’s hot, humid summers with frequent 100°F days and mild but occasionally freezing winters mean cooling dominates the energy budget. Radiant barrier and attic ventilation are critical to prevent heat buildup, while humidity makes proper air sealing essential to avoid mold in wall cavities. Every estimate includes a full attic inspection, and every estimate is free. Call (903) 437-9164 to schedule yours.
We Also Serve Cities Near San Antonio
Our crews serve San Antonio and surrounding communities including Cibolo, Floresville, Boerne, and New Braunfels. If you’re just outside the city on an acreage property, we’ll bring the same written estimate and shoe covers to your door. Response times to these areas run one to two days for estimates, with installation typically scheduled within the week.
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 About Attic Insulation in San Antonio
Yes. The original R-11 batts in Oak Hills homes have compressed over 40 to 50 years of Texas heat, losing most of their insulating value. Blowing in a fresh layer of Owens Corning AttiCat fiberglass to reach R-38 to R-49 typically brings upstairs bedrooms within 3 to 5°F of downstairs. Pair it with air sealing on the top plates and can lights, and the fix holds through the worst of August. Call (903) 437-9164 for a written quote.
Attic insulation helps more than most people expect, but the roll-up door has to be handled too. We insulate the workshop attic and air-seal the top plates, then address the door’s air seal as part of the thermal boundary. On a detached workshop off a gravel drive in the Oak Hills area, our crew removed settled R-11 fiberglass, air-sealed the top plates and can lights, blew in R-38 Owens Corning AttiCat, and installed a radiant barrier under the rafters. The owner had been resetting the overhead door opener monthly because the heat made the spring tension drift. After the upgrade, the upstairs bonus room above the shop held 78°F on a 102°F day without the window unit cycling nonstop.
In most cases, yes. For a King William bungalow with uninsulated or under-insulated walls, we can blow dense-pack cellulose into the wall cavities through small holes drilled in the exterior or interior surface, then patch and repaint. The attic is the bigger win for most older bungalows, and we handle that by air-sealing and blowing in fiberglass to R-49. A written estimate will tell you what your specific house needs and what it will cost before any work starts.
You usually don’t need to remove settled wall batts. We can drill small access holes and blow in additional insulation to fill the voids left by settling, restoring the wall’s thermal performance without tearing out drywall. The attic is typically the priority on 1990s two-story homes, since heat rises and the attic is where the most cooling energy escapes. We’ll inspect both and give you a written number for each option.
In San Antonio’s hot, humid climate, the vapor drive runs from outside to inside most of the year, so a traditional polyethylene vapor barrier on the interior side is not recommended the way it is in northern climates. What matters more here is air sealing and proper ventilation to prevent moist air from reaching cool surfaces and condensing. On spray foam jobs, closed-cell foam acts as its own vapor and air barrier. We’ll explain exactly what your attic needs when we inspect it, and the written price covers everything.
If your San Antonio attic has been ignored since the 1980s, call (903) 437-9164 today. We answer live, 24/7, and we’ll schedule a free attic inspection with a written estimate. No voicemail trees, no vague ranges, no surprises.
Written by Neil Barron, Owner at Thistledown Insulation San Antonio, serving San Antonio since 2003.