Fast, Reliable Spray Foam Insulation Across Alamo Heights
Most spray foam insulation jobs in Alamo Heights run $3,200-$7,800 depending on whether we’re sealing a roof deck, filling balloon-framed walls, or encapsulating a kneewall cavity in a 1940s home near Broadway. We’re typically on-site within 24-48 hours of your call, and every job starts with a written price before anyone mixes a batch. Call (830) 529-7780 for a free estimate.
We’ve worked the 78209 zip code long enough to know that Alamo Heights isn’t just another San Antonio neighborhood. It’s an independent municipality with its own permit process, a tight-knit stock of 1920s-1960s custom homes, and plaster-and-lath walls that don’t forgive a contractor who treats the job like a standard suburban retrofit. Our crews coordinate dispatch from our San Antonio office but live and work in this market, and we pull every Alamo Heights permit through City Hall, not San Antonio Development Services.
Why Topside Attic Insulation Boerne Is Alamo Heights’s Preferred Spray Foam Insulation Company
We’ve sealed and insulated over 9,000 homes since 2016, and a growing share of them sit within Alamo Heights’s city limits. Homeowners here find us the same way most do: they read our three-star reviews as carefully as our five-star ones, they ask for the blower-door numbers, and they want to see the photo documentation before they commit. We don’t perform enthusiasm. We perform air-sealing, and we publish the proof.
Response time to Alamo Heights averages same-day or next-day for standard calls, and our live-answered phone line means you’re talking to a person who can schedule, not a callback queue measured in business days. Under Haven Standard: Arrive on schedule, you get a named technician and a text when they are on the way.
What separates our work here is that we understand the local failure modes. Balloon-framed walls on streets like Tuxedo and Fresno. Kneewall cavities in two-story homes along the Broadway corridor. Pier-and-beam and early slab foundations with settled or absent original insulation. These aren’t hypotheticals for us. They’re what we find on initial inspection, and our written scope accounts for them before any foam is sprayed.
Our Spray Foam Insulation in Alamo Heights reputation rests on one fact: we’ve never damaged original plaster or woodwork on a historic home here because we don’t use the open-bay tear-out methods that work in newer San Antonio suburbs.
Our Spray Foam Insulation Services in Alamo Heights

Closed-Cell Spray Foam
Closed-cell spray foam is our go-to for Alamo Heights’s balloon-framed wall cavities and rim joist applications where vapor control matters. At roughly 2 lbs per cubic foot, it delivers R-6.5 per inch and acts as its own air barrier and vapor retarder. In a 1940s home on Castano or Evans, where the wall depth is fixed by plaster-and-lath thickness, we match the density and lift to the cavity rather than defaulting to a target R-value that would overfill and push plaster keys loose. Most closed-cell jobs in Alamo Heights run $4,500-$8,200 for targeted wall and rim applications.

Open-Cell Spray Foam
Open-cell spray foam, at roughly 0.5 lbs per cubic foot and R-3.6 per inch, is what we use for roof deck applications where we want the assembly to dry to the interior. In Alamo Heights’s 150°F summer attics, spraying open-cell directly to the roof deck creates a conditioned attic that stops ductwork from cooking in the chase, which is why many homeowners pair this with our Attic Insulation in Alamo Heights for complete thermal protection. We source open-cell from Icynene and Demilec, matching the product to the specific roof assembly. Typical roof deck jobs here run $3,200-$6,400 depending on pitch and accessibility.

Rim Joist Spray Foam
The rim joist is where the foundation meets the floor system, and in Alamo Heights’s pier-and-beam and early slab homes, it’s often completely unsealed. We use closed-cell spray foam here because the rim joist sees both air leakage and potential moisture from the perimeter soil. On a 1930s home near Alamo Heights Avenue, we recently sealed a rim joist assembly that was pulling 380 CFM50 of unconditioned air through a 2-inch gap. The blower-door test dropped to 2,100 CFM50 after sealing and insulating. Most rim joist jobs run $1,800-$3,400.

Garage Ceiling Spray Foam
Garage ceiling spray foam in Alamo Heights addresses a specific local problem: attached garages with bedrooms above them that bake in summer and freeze in winter. We spray open-cell or closed-cell depending on whether the garage is conditioned or ventilated, and we always seal the top plates and penetrations first. On a recent job near New Braunfels Avenue, the second-floor bedroom above an uninsulated garage was running 14°F off the main house thermostat. After spraying the garage ceiling and sealing the rim, the delta dropped to 3°F. Typical garage ceiling jobs run $2,400-$4,800.

Spray Foam Roof Deck
Spray foam roof deck application is the single highest-return upgrade for Alamo Heights’s pre-1970 homes with HVAC ductwork in the attic. Instead of insulating the attic floor and leaving ducts to radiate heat, we spray directly to the roof deck and bring the ductwork inside the conditioned envelope. This requires careful attention to the existing ventilation strategy, and in Alamo Heights, we always pull a permit through City Hall to verify the assembly meets local code. Our Spray Foam Insulation team has completed over 200 roof deck jobs in the 78209 zip code, and we publish before-and-after blower-door numbers on every one.

What happens when you call
- 1
A real person answersNo phone trees - you reach a local pro.
- 2
You get an upfront price rangeHonest numbers before anyone is dispatched.
- 3
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 Alamo Heights
We source spray foam materials from Owens Corning, Johns Manville, Knauf, and Icynene, among others, with no proprietary product lock-in. For Alamo Heights homeowners, this means we specify the right foam for the assembly rather than pushing whatever’s in the truck. Closed-cell from Icynene for rim joists and balloon-framed walls. Open-cell from Owens Corning or Johns Manville for roof decks where drying potential matters. We stock local inventory for fast turnaround, and every batch is documented with manufacturer lot numbers in your job record.
Common Spray Foam Insulation Problems We See in Alamo Heights Homes

- San Antonio permitting assumed. Contractors working across the broader metro pull a San Antonio permit and proceed, only to discover Alamo Heights City Hall requires its own inspection sequence. We pull every permit through the correct jurisdiction before work starts.
- High-pressure closed-cell into balloon-framed chases. The pressure pushes plaster keys loose and leaves ornate wood trim proud of the wall. The damage isn’t visible until the next paint cycle. We use low-pressure application and small-diameter penetrations to avoid this.
- Foam sprayed over settled original insulation. Trapping old batts or moisture-laden cellulose against a pier-and-beam underside or slab edge creates a rot risk in 1940s homes with no vapor barrier. We remove or verify the condition of existing material before spraying.
- Uninsulated kneewall cavities in two-story homes. On streets like Tuxedo and Fresno, these balloon-framed chases pull outdoor air straight from the roofline to the living space. We find them on initial inspection and address them in the written scope.
Pricing for Spray Foam Insulation in Alamo Heights, TX
| Service | Typical Range in Alamo Heights |
|---|---|
| Rim Joist Spray Foam | $1,800 - $3,400 |
| Garage Ceiling Spray Foam | $2,400 - $4,800 |
| Open-Cell Roof Deck | $3,200 - $6,400 |
| Closed-Cell Wall/Rim (targeted) | $4,500 - $8,200 |
| Full Attic Conversion (roof deck + air sealing) | $5,800 - $11,500 |
What moves the number: cavity depth and accessibility, whether we’re drilling through exterior brick or working from interior closets, the condition of existing insulation that must be removed first, and whether the home has active knob-and-tube wiring that requires electrical coordination. Every Alamo Heights job gets a written price before any work starts, and we offer a Free Second Opinion on any competing written estimate. Call (830) 529-7780 for your exact quote.
We Also Serve Cities Near Alamo Heights

Our crews work throughout the northern San Antonio metro, including Alamo Heights, Boerne, Fair Oaks Ranch, Scenic Oaks, and Helotes. Dispatch and scheduling are coordinated from our San Antonio office, with local crews serving each market.
Serving Alamo Heights, TX - Our Local Coverage Area
We’re based in the Alamo Heights 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 - Spray Foam Insulation in Alamo Heights

Yes. Alamo Heights is an independent municipality with its own permit and inspection process through City Hall, and attic spray foam jobs require a permit separate from San Antonio’s jurisdiction. We pull every permit before work starts and schedule the inspection sequence so there’s no hold-up at closeout. Call (830) 529-7780 and we’ll confirm the permit status for your specific address.
Yes, when the job is scoped for small-diameter drill penetrations and low-pressure application rather than open-bay tear-out. On a 1940s two-story on Tuxedo near Broadway, we used Icynene closed-cell sprayed through small penetrations in the closet knee wall to seal the rim and cap the chimney chase, then added Icynene open-cell to the roofline deck. The homeowner reported a 9-12°F drop in second-floor summer ceiling temps and no visible damage to the original wood trim or plaster. We document every penetration point with photos before and after.
Yes, when the density and lift are matched to the specific wall depth rather than defaulting to a target R-value. The danger isn’t the foam itself; it’s high-pressure application that overfills the cavity and pushes plaster keys loose. We use low-pressure closed-cell and verify the cavity volume with a borescope before spraying. Your written scope specifies the pressure settings and lift schedule.
No. Our method preserves interior finishes by working from the exterior or through minimal interior penetrations in closets and utility chases. The 365-Day Done Right Promise applies: if any trim or plaster is disturbed, we make it right. We provide a Documented Photo Record of every penetration point so you have a record of the home’s condition before and after.
Closed-cell spray foam at the rim joist and in balloon-framed walls eliminates the thermal bypass channels that made 1940s-1950s brick homes so vulnerable during the February 2021 freeze. A continuous air barrier plus insulation stops the stack effect that pulls cold air through the wall assembly. After Uri, we saw a spike in Alamo Heights homeowners requesting rim joist and wall cavity work specifically. The blower-door test proves the result: we measure it, we publish it, you verify it.
Written by Wes Okafor, Owner at Topside Attic Insulation Boerne, serving Alamo Heights since 2016.