Fast, Reliable Spray Foam Insulation Across Alamo Heights
Spray foam insulation in Alamo Heights typically costs $2.80-$5.40 per board foot installed, with most whole-attic retrofits running $4,200-$8,600 depending on whether open-cell or closed-cell foam is used and how complex the roofline is. We’re the Spray Foam Insulation crew that serves Alamo Heights from our San Antonio dispatch office, and we answer calls live 24/7 at (830) 420-0953. Most Alamo Heights appointments are scheduled within 48 hours because we know the area well - from the winding streets off Broadway to the older homes near the Quarry - and we don’t make you wait through callback windows.
Alamo Heights is different from the rest of the metro. The homes here are older, larger, and built with materials you can’t replace at a hardware store. That matters when you’re choosing a spray foam contractor because the wrong approach damages what can’t be undone.
Why Topside Attic Insulation Converse Is Alamo Heights’s Preferred Spray Foam Insulation Company
We’ve worked on enough Alamo Heights homes to know the pattern before we pull into the driveway. The 1920s Tudor off Austin Highway with the original plaster crown molding. The 1948 ranch near Alamo Heights High School with three additions, each framed differently. The Corona Avenue cottage where the attic still had knob-and-tube from before Pearl Harbor. Our reputation here is built on not being surprised by any of it.
Homeowners in Alamo Heights research thoroughly before they call, and they should. We publish our before-and-after blower-door numbers on every applicable job so you can verify the air-sealing result in a single figure, not take our word for it. Our 365-Day Done Right Promise applies to all completed work, and every job starts with a written price and scope under Haven Standard Clause 1 - flat price, written scope, written warranty before anyone lifts a tool.
Calls are answered by a live person, 24/7. No voicemail loops. No “we’ll call you back Tuesday.” When you need a free second opinion on any written estimate from another contractor, bring it to us and we’ll read it with you line by line.
Our Spray Foam Insulation Services in Alamo Heights
Open-Cell Spray Foam
Open-cell spray foam is our most common recommendation for Alamo Heights’s older homes with plaster-on-lath walls and complex rooflines. At roughly half-pound density, it expands to fill irregular cavities in balloon-framed walls and rafter bays of varying depths - exactly what you find in a 1935 home that’s had two additions. It breathes, which matters in Alamo Heights’s humid subtropical climate, and it won’t generate the pressure that can crack original plaster. Most open-cell attic jobs in Alamo Heights run $2.80-$3.80 per board foot installed.
Closed-Cell Spray Foam
Closed-cell foam at 2-pound density delivers higher R-value per inch and acts as its own vapor barrier. We use it selectively in Alamo Heights - typically for rim joists in pier-and-beam foundations, garage ceiling applications where headroom is limited, or exterior walls where every fraction of an inch counts. It’s not our default for attic roof decks in historic homes because the rigidity can stress older substrates. When we do specify closed-cell in Alamo Heights, it’s with full masking of original millwork and a written plan for protecting irreplaceable finishes. Closed-cell work here typically runs $4.20-$5.40 per board foot.
Rim Joist Spray Foam
The rim joist is where your floor framing meets the foundation, and in Alamo Heights’s older homes it’s often completely unsealed. Winter air pours in here, and summer humidity follows. We spray closed-cell foam into these cavities after sealing all penetrations, which stops the stack effect that pulls conditioned air out of your living space. On a 1941 plaster-on-lath home off Corona Avenue, our crew found original knob-and-tube wiring in the attic joist bays and a complex roofline with three different rafter depths from separate additions. We first had the legacy wiring decommissioned, then applied open-cell spray foam across the roof deck and rim joists to stop the 140°F summer attic heat gain and the winter freeze losses that showed up after Uri. The result was a sealed, code-compliant thermal envelope without disturbing the original plaster walls or millwork the owners were determined to preserve.
Garage Ceiling Spray Foam
Attached garages in Alamo Heights’s older homes often have uninsulated ceilings that act as thermal bridges straight into bedrooms above. We spray foam these ceilings after air-sealing all top plates and penetrations, which keeps the rooms above from baking in summer and freezing in winter. Because garage ceilings in these homes are frequently low, we often use closed-cell foam here to maximize R-value in limited space.
Spray Foam Roof Deck
Spray foaming the roof deck - rather than the attic floor - creates a conditioned attic space that’s especially valuable in Alamo Heights’s 1920s-1950s homes with HVAC ductwork running through 140°F attics. The foam is applied directly to the underside of the roof sheathing, bringing the attic into the thermal envelope and eliminating the extreme temperature swings that destroy duct efficiency. This is our preferred approach for Alamo Heights homes with original plaster ceilings we can’t disturb, and for any home where the attic contains ductwork that deserves to live in conditioned space.
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.
Before
AfterTrusted Brands We Service in Alamo Heights
We source spray foam materials from established manufacturers including Johns Manville, Knauf, and CertainTeed - no proprietary lock-in that limits your options or inflates your price. For Alamo Heights homeowners, this means we specify the right product for your specific assembly rather than forcing a one-size-fits-all solution. Our crews carry stock for common Alamo Heights applications, and when a job requires something specialized for a historic substrate or unusual cavity, we source it without extended lead times. You get the material that belongs in your home, not whatever we happen to have on the truck.
Common Spray Foam Insulation Problems We See in Alamo Heights Homes
- Live knob-and-tube wiring hidden in joist bays. In Alamo Heights, spray foam crews routinely hit original 1920s-1950s knob-and-tube wiring still running through attic joist bays and wall cavities, a condition that almost never appears in the post-1980s tract subdivisions just across the San Antonio line and must be resolved before any spray foam or blown insulation can legally be installed. Foam applied over live knob-and-tube creates a code violation and a hidden heat/fire risk that only surfaces during a later inspection.
- Closed-cell foam overspray on irreplaceable finishes. When crews fail to mask delicate 1920s-1950s plaster-on-lath or historic millwork, closed-cell foam bonds permanently to surfaces that cannot be matched or replicated. We’ve been called in to fix this after other contractors treated a Corona Avenue craftsman like a new-construction tract home.
- Foam cracking or delaminating in multi-era additions. A single Alamo Heights home may have three or four distinct wall and attic assemblies from additions built in the 1940s, 1960s, and 1980s. When the substrate is prepped as if it were one uniform cavity, the foam fails at the transition points between different materials and depths.
- Unsealed chase gaps in balloon-framed walls. Ignoring the complex roofline and balloon-framed walls common here leaves vertical air channels that short-circuit the thermal envelope even after foaming the visible roof deck. The attic looks insulated, but air is still moving through walls you can’t see.
Pricing for Spray Foam Insulation in Alamo Heights, TX
Here’s what spray foam insulation costs in Alamo Heights’s market, based on jobs we’ve completed here:
| Application | Price Range (Installed) | Typical Total Job |
|---|---|---|
| Open-cell attic roof deck | $2.80-$3.80 / board foot | $4,200-$6,800 |
| Closed-cell rim joists | $4.20-$5.40 / board foot | $1,800-$3,400 |
| Closed-cell garage ceiling | $4.20-$5.40 / board foot | $2,400-$4,200 |
| Whole-attic open-cell with air sealing | $2.80-$3.80 / board foot | $5,600-$8,600 |
What moves you within these ranges: the condition of existing wiring (knob-and-tube remediation adds cost), the number of distinct roofline sections from additions, accessibility of rim joists in crawl spaces, and whether we’re working around original finishes that require extensive masking. Every job begins with a written price before any work starts - Haven Standard Clause 1 - and we provide free estimates. Call (830) 420-0953 for yours.
We Also Serve Cities Near Alamo Heights
Our crews work throughout the San Antonio metro, including Alamo Heights and nearby Converse, Universal City, Live Oak, and Windcrest. Scheduling is coordinated from our San Antonio office, with local crews dispatched to each area.
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
No - live knob-and-tube wiring must be decommissioned by a licensed electrician before any insulation, including spray foam, can legally be installed. We identify this condition during our initial assessment, document it with photos, and can recommend electricians we’ve worked with in Alamo Heights who understand historic homes. Call (830) 420-0953 and we’ll walk you through the sequence - estimates are free.
Open-cell is almost always our recommendation for attic and roof deck applications in Alamo Heights’s plaster-walled homes. Its lighter density and vapor-permeability won’t generate the pressure that cracks original plaster, and it fills irregular cavities in balloon-framed walls without forcing rigid foam against delicate substrates. Closed-cell has its place for rim joists and limited-space applications, but it’s not our default for historic interiors. We’ll specify what’s appropriate after seeing your specific assemblies - call (830) 420-0953 for a free assessment.
We mask every surface that isn’t being foamed with polyethylene sheeting and painter’s tape rated for delicate substrates, and we use low-pressure application near finished edges. Our crews are trained to recognize the difference between replaceable drywall and irreplaceable 1920s plaster - and we document the masking with photos before foam goes in. The Documented Photo Record is included on every job, not available on request. You’ll see exactly how we protected your home.
Because each addition was likely built with different framing, different rafter depths, and different existing insulation conditions. A 1935 original may have 2×6 rafters and balloon framing, while a 1972 addition has 2×4 trusses and platform framing. Applying the same foam type and thickness to both creates gaps at the transitions and can overfill or underfill cavities. We assess each section separately, specify the right product and depth for each assembly, and document the plan in writing before work starts. That’s Haven Standard - Have it in writing.
Yes - it’s one of the most effective upgrades for both conditions. San Antonio’s climate drives attic temps routinely above 140°F in summer, and the February 2021 Winter Storm Uri exposed how poorly Alamo Heights’s vintage homes retain heat during hard freezes. Spray foam on the roof deck or attic floor creates an air-sealed thermal boundary that blocks both heat gain and heat loss. We verify the result with before-and-after blower-door tests on applicable jobs - a pressurization reading that shows, in one number, how much conditioned air your home was losing before and after the work. Call (830) 420-0953 for a free estimate and we’ll show you what the numbers would look like for your home.
Ready to see what spray foam can do for your Alamo Heights home? Call (830) 420-0953 for a free estimate. We’ll provide a written price before any work starts, a documented photo record when the crew leaves, and before-and-after blower-door numbers on every applicable job so you can verify the result yourself. Our 365-Day Done Right Promise applies to all completed work, and a live person answers the phone 24/7.
Written by Wes Okafor, Owner at Topside Attic Insulation Converse, serving Alamo Heights since 2016.