Trusted Spray Foam Insulation for San Antonio Homeowners
Spray foam insulation in San Antonio typically costs $2.50 to $6.50 per square foot installed, depending on whether you choose open cell or closed cell foam and how much surface area needs coverage. Most whole-attic spray foam jobs in San Antonio run $4,800 to $9,500, and we complete most installations in one day. Call (361) 213-9499 for a free, no-pressure estimate with the price in writing before any work starts.
Aspen Attic Insulation San Antonio has been insulating homes across Bexar County since 2002, and we’ve seen what San Antonio summers do to under-insulated attics. When your attic hits 140 degrees in July, your AC works double shifts and your electric bill shows it. Spray foam seals the gaps that fiberglass batts leave open, cutting air movement through your attic, walls, and crawl space. Garrett Sloane leads our San Antonio crew, and every technician who shows up at your door is background-checked, uniformed, and photo-badged. We send you their name and photo before the visit so you know exactly who’s knocking. No surprises at the door, no surprises on the bill.
Closed Cell Spray Foam Insulation
Closed cell spray foam insulation is a high-density foam that expands to roughly 1 to 1.5 inches per application pass and cures into a rigid, moisture-resistant barrier with an R-value of about R-6.5 to R-7 per inch. We recommend closed cell in San Antonio for homes where you want structural reinforcement along with insulation, or where moisture from humidity and seasonal rain is a real concern. It costs $3.50 to $6.50 per board foot installed, and a typical San Antonio attic runs $6,000 to $9,500. Aspen Attic Insulation San Antonio installs closed cell from Demilec and Icynene, and your written price includes all labor, materials, and cleanup.
Moisture and Humidity Control
San Antonio’s average relative humidity hovers around 67% year-round, and closed cell foam acts as a vapor barrier that keeps that damp air from soaking into your roof decking and wall cavities. In crawl spaces and rim joists, closed cell prevents the condensation that causes mold and wood rot. We see this most often in older homes near Alamo Heights and Terrell Hills where vented crawl spaces pull in humid air every summer.
Structural Reinforcement
Closed cell spray foam adds shear strength to walls and rooflines once it cures, which is why some San Antonio homeowners choose it before hurricane season or after roof repairs. The foam bonds to the substrate and stiffens the assembly without adding meaningful weight. It’s not a substitute for proper framing, but it does make the building envelope noticeably stronger.
Open Cell Spray Foam
Open cell spray foam is a lighter, semi-rigid foam with an R-value around R-3.5 to R-3.8 per inch, designed primarily for sound dampening and air sealing rather than moisture control. In San Antonio, open cell works well in attics and interior walls where you want to stop air movement and quiet things down without paying for closed cell density. It costs $2.50 to $4.50 per board foot installed, and a standard San Antonio attic typically runs $4,800 to $7,200. Aspen Attic Insulation San Antonio uses open cell foam from Icynene and Demilec, chosen for consistent curing in South Texas heat.
Attic Air Sealing
Open cell foam expands up to 100 times its liquid volume, filling every crack, gap, and odd corner in an attic roofline. That expansion is why it works so well in San Antonio homes with complex rooflines, recessed lighting, or existing ductwork running through unconditioned space. We’ve insulated attics in Castle Hills and Kirby where fiberglass batts had been patched four times and still leaked air around every penetration.
Sound Dampening
Open cell spray foam is a good choice for interior walls and ceilings where noise transfer is the main complaint, especially in two-story homes and townhomes near Live Oak and Universal City. The foam’s cell structure absorbs sound instead of reflecting it, reducing the noise moving between floors and rooms. It’s not a recording-studio solution, but it makes a noticeable difference in day-to-day living.
Spray Foam Insulation Contractors
Spray foam insulation contractors are the crews who install foam insulation into attics, walls, rim joists, and crawl spaces using specialized proportioner equipment and professional-grade chemical blends. In San Antonio, you want a contractor who has been doing this long enough to know how foam behaves in 100-degree heat and high humidity, because bad installations cure wrong and are expensive to fix. Most San Antonio spray foam contractors charge $3,000 to $12,000 per project depending on scope, and Aspen Attic Insulation San Antonio operates with a written price before work begins. Garrett Sloane’s crew has installed foam across Bexar County since 2002.
How We Verify Our Technicians
Every Aspen technician is identity-verified, background-checked, and sent to your home with a photo ID badge and marked uniform. We send you their name and photo before the visit. If anyone else shows up claiming to be from Aspen, the visit is free and we make it right. That’s the Threshold Standard, and it’s our minimum.
Why Written Pricing Matters
Spray foam jobs can hide a lot of costs in verbal estimates, and we’ve seen San Antonio homeowners get burned by crews who added fees for “excess foam” or “unexpected prep work” after the fact. Our written price covers everything from setup to cleanup, no add-ons. If it’s on the quote, that’s what you pay.
Spray Foam Attic Insulation
Spray foam attic insulation seals the attic roofline or floor with expanding foam that blocks the air movement responsible for most of San Antonio’s cooling loss. In a typical San Antonio summer, your attic can reach 140 to 150 degrees, and that heat pours down through your ceilings unless the barrier is continuous. Spray foam attics run $4,800 to $9,500 in San Antonio depending on square footage and foam type, and most installations finish in one day. Aspen Attic Insulation San Antonio insulates attic rooflines, attic floors, and attic access points.
Roofline Foam Applications
Foaming the roofline turns the attic into semi-conditioned storage space and protects ductwork from sitting in extreme heat. If your HVAC ducts run through the attic, which they do in most San Antonio slab homes, this is the application that cuts your cooling bill most. We’ve insulated rooflines in Helotes and Fair Oaks Ranch where homeowners reported 15% to 25% lower electric bills the first summer.
Insulating Around Existing Ductwork
Most San Antonio attics have ductwork with aging or partial insulation, and spray foam is one of the few materials that seals directly around ducts, vents, and plenums without leaving air gaps. The foam adheres to the metal and flex duct, creating a continuous thermal boundary. It works especially well in older homes in Alamo Heights and Terrell Hills where duct replacement isn’t in the budget this year.
Spray Foam Wall Insulation
Spray foam wall insulation fills wall cavities with expanding foam that stops air infiltration through the wall assembly, which is the second biggest source of energy loss in San Antonio homes after the attic. For existing homes, installers typically drill access holes and inject foam into each stud bay, or foam walls during new construction and major remodels before drywall goes up. Wall foam projects in San Antonio run $3,000 to $8,000 depending on wall area and accessibility. Aspen Attic Insulation San Antonio handles both open wall retrofit and enclosed cavity injection.
Retrofit Wall Cavity Injection
For homes already built, foam can be injected into wall cavities through small holes drilled in the drywall or exterior siding, then patched clean. It’s more involved than attic work and takes one to two days for most San Antonio homes, but it stops the drafts and uneven temperatures that plague older construction. We’ve done injection work in Bulverde and Castle Hills where the original insulation had settled to half its original depth.
New Construction and Remodel Applications
If walls are already open, spray foam goes in fast and cures to a complete air and thermal barrier behind the drywall. We work with San Antonio general contractors on remodels and additions in Live Oak and Kirby, coordinating the insulation schedule so the project doesn’t stall. Your written price includes the full wall scope with no per-cavity surprises.
Rim Joist Spray Foam
Rim joist spray foam seals the band board where your foundation meets your floor framing, the spot where outside air leaks into basements and crawl spaces in San Antonio homes. Rim joists are often left completely uninsulated during original construction, and on humid days the exposed wood sweats and feeds mold. Rim joist foam sealing runs $900 to $2,500 for a typical San Antonio home, and most jobs finish in half a day. Aspen Attic Insulation San Antonio uses closed cell foam from Demilec for rim joists because the moisture resistance is worth it at this location.
Stopping Air Movement at the Foundation Line
The rim joist is the single leakiest seam in most crawl space and pier-and-beam homes around San Antonio, especially in older neighborhoods like Terrell Hills and Alamo Heights. Foam seals the wood-to-wood joints that caulk and fiberglass can’t fill. Once sealed, floor temperatures rise noticeably in winter.
Moisture Protection at the Sill Plate
Because closed cell foam blocks vapor movement, it protects the sill plate and rim joist from the condensation that leads to rot and insect activity. San Antonio’s humid springs make this a real problem in vented crawl spaces. Sealing now is cheaper than replacing a rotted rim joist in five years.
Crawl Space Spray Foam Insulation
Crawl space spray foam insulation coats the underside of your floor or the crawl space walls with foam that seals out ground moisture and outside air, turning a damp vented crawl into a clean conditioned space. In San Antonio, vented crawl spaces pull in humid air all summer, which soaks your floor joists and makes your home feel muggy even with the AC running. Crawl space foam runs $3,500 to $7,000 for most San Antonio homes depending on access and square footage. Aspen Attic Insulation San Antonio applies closed cell foam from Icynene to crawl space walls and rim joists for a complete moisture and air seal.
Encapsulation with Spray Foam
Foaming crawl space walls instead of the floor creates what’s called an encapsulated or conditioned crawl space, the same air quality as the rest of the house. It stops the musty smell that rises into living spaces and keeps floor temperatures stable. We’ve converted crawl spaces in Fair Oaks Ranch and Helotes where homeowners had fought musty odors for years with dehumidifiers and vents.
Underside Floor Applications
For some San Antonio homes, foaming the underside of the floor is a better fit, especially when the crawl space has limited access or the homeowner isn’t ready for full encapsulation. The foam seals gaps around plumbing penetrations and electrical runs, which is where most air and insects get in. It’s a solid mid-price option that still stops most of the moisture and air movement.
Garage Spray Foam Insulation
Garage spray foam insulation seals the garage ceiling and walls so your garage stops radiating heat into adjacent rooms and your water heater doesn’t work as hard. In San Antonio, a west-facing garage door can push garage temperatures past 130 degrees in August, and that heat soaks through the shared wall into your living space. Garage foam insulation runs $1,800 to $4,200 for a typical two-car San Antonio garage. Aspen Attic Insulation San Antonio sprays garage ceilings, shared walls, and the area above the garage door where the biggest gaps usually are.
Ceiling and Shared Wall Sealing
The wall between the garage and the house is rarely insulated well in the original build, especially in production homes around Live Oak and Universal City. Foaming the garage ceiling and that shared wall brings a quick and measurable drop in the temperature of rooms adjacent to the garage. If a bedroom sits over the garage, this is one of the best-value insulation upgrades we do.
Garage Door Gap Sealing
Spray foam can’t be applied directly to a moving garage door, but the gaps around the door frame, the top rail, and any side weatherstripping are prime candidates for foam sealing. We seal the perimeter and insulate whatever surrounds the door opening. It’s not a substitute for an insulated garage door, but it eliminates the biggest drafts.
Brands We Service
We install spray foam from Demilec and Icynene. Demilec’s closed cell foam cures hard and consistent even when San Antonio heat pushes ambient temperatures past 100 degrees, and we’ve used their Heatlok product line on hundreds of attics and crawl spaces with predictable results. Icynene’s open cell foam expands reliably in tight cavity work and holds its shape without shrinking, which matters in wall injection and rim joist applications.
For blown-in and batt applications that pair with spray foam jobs, we also stock CertainTeed and GreenFiber. CertainTeed’s fiberglass batts and rolls fit wall and floor cavities where foam isn’t the best tool, and GreenFiber’s cellulose is a good fit for attic floors over foam-sealed rooflines. Whatever brand you have currently or whichever material fits your job, Aspen Attic Insulation San Antonio can help and will put the right product in, not just the available one.
Signs You Need a Pro Right Now
- Your electricity bill jumped without a life change. San Antonio summers punish under-insulated attics hard, and a 20% or 30% year-over-year bill increase with the same thermostat settings typically means your air barrier has failed. The heat you’re paying to fight is leaking through your ceiling.
- One room stays hot while the rest of the house is fine. If your upstairs bedroom or a room over the garage never cools down, the wall or ceiling cavity likely has no insulation or settled insulation. Spray foam fills the cavity completely and stops the hot wall effect.
- You smell musty air from your crawl space. That damp, earthy smell means ground moisture is moving into your floor system, and it will not go away on its own. Closed cell spray foam on the crawl space walls or floor stops the vapor at the source.
- You can feel drafts around baseboards and outlets. Air moving through wall cavities around outlets, switches, and baseboards means your wall insulation is incomplete or missing. Foam injection seals the cavity and stops the draft, not just the symptom.
- Your AC runs constantly but the house never feels comfortable. In San Antonio’s climate, constant AC runtime with poor comfort is almost always an air sealing problem, not a sizing problem. Sealing the attic and rim joists with spray foam reduces the air exchange your system is fighting.
Our Process, Step by Step
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Call us and get a real person. We answer the phone 24/7, no voicemail loops and no callback windows. You describe the problem in your own words, and we book an assessment at a time that works for you.
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Free on-site assessment. A background-checked tech in a marked uniform, with a photo ID badge, shows up at your door at the scheduled time. We inspect the attic, walls, rim joist, or crawl space, measure square footage, and identify air leaks with a thermal camera where relevant.
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Written price before work starts. You receive a written quote covering labor, materials, cleanup, and any access work. That’s the price you pay. No add-ons, no surprise fees after the fact.
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Installation day. We protect floors and walls, set up the proportioner, and apply the foam to the agreed-upon spec. Most San Antonio attic jobs finish in one day; wall and crawl space work may take one to two days. We walk you through the result before we leave.
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365-Day Done Right Promise. Our written guarantee covers labor and materials for a full year. If anything isn’t right, we come back and fix it free. That’s the deal, in writing, every job.
How Much Does Spray Foam Insulation Cost in San Antonio?
A typical open cell attic spray foam job in San Antonio runs $4,800 to $7,200, while a closed cell attic runs $6,000 to $9,500 depending on square footage, roof pitch, and access. Wall cavity injection runs $3,000 to $8,000. Rim joist sealing runs $900 to $2,500, and crawl space foam runs $3,500 to $7,000. Garage foam runs $1,800 to $4,200 for a two-car space. These are real ranges we quote in San Antonio, not national averages.
What moves the price is square footage, foam type, access difficulty, and whether we’re retrofitting or working in open framing. To avoid overpaying, get a written quote that includes everything: setup, foam, labor, cleanup, and any patching. If a contractor won’t put the full number on paper before starting, walk away. Our free estimate includes the full written price and a foam type recommendation based on your home, not on what’s easiest for us.
Our Service Area Near San Antonio
We serve San Antonio and the surrounding communities: Alamo Heights, Terrell Hills, Castle Hills, Kirby, Live Oak, Universal City, Schertz, Helotes, Fair Oaks Ranch, Bulverde, and Lackland AFB. Typical response time is same day or next day depending on your location and our schedule. If you’re in Schertz, see our Spray Foam Insulation in Schertz page. If you’re near Universal City, see Spray Foam Insulation in Universal City. And for a full overview of the service, see our Spray Foam Insulation in San Antonio page. Back to home.
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.
Frequently Asked Questions About Spray Foam Insulation in San Antonio
Spray foam insulation is a two-part liquid that expands on contact to fill cavities with a continuous air and thermal barrier. It seals gaps that fiberglass and cellulose leave open, and in San Antonio it’s the single most effective way to stop hot attic air from pushing into living space. You can learn more on our Spray Foam Insulation in San Antonio page. Call (361) 213-9499 for a free estimate.
Most San Antonio attic spray foam jobs are done in one day, including setup and cleanup. Wall injection and crawl space work usually takes one to two days depending on access and square footage. We’ll give you a specific time window in your written quote.
Open cell attic foam runs $4,800 to $7,200, closed cell runs $6,000 to $9,500, and smaller jobs like rim joists run $900 to $2,500. Every job gets a written price before work starts. Call (361) 213-9499 for an exact quote, free.
Yes, we install open cell and closed cell foam from Demilec and Icynene, and we stock CertainTeed and GreenFiber for complementary batt and blown-in applications. We match the material to the specific job. Call us and we’ll walk you through the right choice for your home.
We answer the phone 24/7 and can often schedule same-day or next-day assessments across San Antonio and nearby cities. Emergency situations get priority, and every visit starts with a free inspection and a written price. Call (361) 213-9499 and ask for Garrett’s team.
The 365-Day Done Right Promise covers labor and materials in writing for a full year on every spray foam job. If a repair fails, you get a free second visit. It applies to every job we do in San Antonio, no exceptions.
Clear access to the attic hatch, crawl space entry, or garage walls, and move anything fragile below the work area. We protect floors and furnishings with drop cloths, and we’ll tell you exactly what to clear before the crew arrives. It takes about 15 minutes of prep on your end for most jobs.
Schedule Your Spray Foam Insulation Service in San Antonio Today
Get the exact price for spray foam insulation in San Antonio before any work begins, with a background-checked technician you’ll know by name and photo before the visit. Call (361) 213-9499 for a free, no-obligation estimate, 24/7, and we’ll put our recommendation and the full written price in your hands. The Spray Foam Insulation in San Antonio page has more detail on the service, and we’re ready when you are.
Written by Garrett Sloane, Owner at Aspen Attic Insulation San Antonio, serving San Antonio since 2002.