Fast, Reliable Spray Foam Insulation Across Terrell Hills
Spray foam insulation in Terrell Hills typically runs $2.80-$5.40 per board foot depending on open-cell or closed-cell product, and most attic and rim-joist jobs are completed in one to two days with the home ready for re-occupancy the same evening. We’re familiar with the permitting process at Terrell Hills city hall, and our crews coordinate dispatch from our San Antonio office to reach Bel Meade, Oak Park, and the older neighborhoods off Terrell Road with same-day or next-day scheduling. Call (830) 529-7780 for a written price before any work starts.
Why Topside Attic Insulation Boerne Is Terrell Hills’s Preferred Spray Foam Insulation Company
We’ve sealed and insulated more than 9,000 homes since 2016, and a significant share of those have been in the enclave communities surrounded by San Antonio. Terrell Hills stands apart because it’s not San Antonio for permitting purposes, and crews who assume Bexar County paperwork routinely discover their mistake at final inspection. We don’t make that assumption.
Our Terrell Hills customers find us through referrals from neighbors who’ve seen our blower-door numbers, the before-and-after documentation we publish on every applicable job. Reviews from local homeowners mention specifically that we found empty wall cavities their previous contractor never checked, and that we delivered a written scope and warranty before anyone lifted a tool. That’s Haven Standard Clause 1.
Response time to Terrell Hills is same-day or next-day for estimates, with crews typically on-site within 48 hours of written approval. Calls are answered by a live person 24/7, no voicemail loops.
Wes Okafor, who leads our operation, established the documentation protocols we still use: every job begins with a written price and ends with a Documented Photo Record plus blower-door readings where air sealing is performed. Homeowners in Terrell Hills receive the same documentation package as any other client, with the added specificity that their permit was pulled correctly through Terrell Hills city hall the first time.
Our Spray Foam Insulation Services in Terrell Hills

Open-Cell Spray Foam
Open-cell spray foam expands to roughly 100 times its liquid volume, creating a soft, permeable insulation layer ideal for attic floors and wall cavities in Terrell Hills’s vented attics. At 3.5 inches, it delivers approximately R-13.5 and allows moisture vapor to pass through, which matters in San Antonio’s humidity because it reduces the risk of trapped condensation against old brick. A typical open-cell attic job in a 2,400-square-foot Terrell Hills ranch runs $3,200-$4,800. We use products from Icynene and Demilec, specified to the cavity depth and condition we find after removing degraded original insulation.

Closed-Cell Spray Foam
Closed-cell spray foam is a rigid, dense product at 2 pounds per cubic foot, delivering R-6.5 per inch and forming both an air barrier and a vapor barrier in one application. In Terrell Hills, we specify closed-cell for rim joists, roof decks, and any exterior-facing north wall where the February 2021 freeze revealed near-zero existing insulation. The material rejects bulk water and adds structural rigidity to the building envelope. Closed-cell runs higher at $4.50-$5.40 per board foot, but in a Terrell Hills brick home with uninsulated wall cavities, it’s often the only product that can achieve code-minimum R-value in a 2×4 stud bay. Our crews are trained in the application thickness limits that prevent over-application and waste.

Rim Joist Spray Foam
The rim joist, where the foundation meets the first floor, is the most common overlooked air leak in older homes. In Terrell Hills’s 1950s-60s custom brick ranches, rim joists were typically left completely open to the exterior, with nothing but a thin strip of tar paper or nothing at all. We spray closed-cell foam to a minimum 2-inch thickness here, creating a continuous thermal and air barrier that stops the stack effect from pulling conditioned air down into the crawl space or slab perimeter. This is the single most cost-effective spray foam application for freeze protection in Terrell Hills homes, and it’s where we see the most dramatic blower-door improvement per dollar spent.

Garage Ceiling Spray Foam
Terrell Hills homes with attached garages often have bonus rooms or bedrooms above, and the garage ceiling is frequently a gaping thermal hole with no air sealing at all. We spray open-cell foam across garage ceilings to separate the conditioned space above from the unconditioned garage below, paying particular attention to the wall-to-ceiling junction where framing irregularities create bypasses. This application typically runs $1,800-$2,800 for a two-car garage in the area, depending on whether the ceiling is finished or open joist.

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 Terrell Hills
We specify materials from Owens Corning, Icynene, Demilec, and GreenFiber based on what the assembly requires, not what we have a truckload of. For Terrell Hills’s older brick homes with complex rooflines and large attic volumes, we stock both open-cell and closed-cell formulations rated for the temperature and humidity conditions of South Texas. No proprietary lock-in means if a specific product is back-ordered, we can substitute an equivalent from another manufacturer without delaying your job. Our San Antonio warehouse carries the full range, so Terrell Hills customers aren’t waiting on a shipment from Houston or Dallas.
Common Spray Foam Insulation Problems We See in Terrell Hills Homes

- Spray foam applied over original rock wool without full removal. The old insulation masks air leaks at top plates and can light housings, and the uneven surface prevents proper foam adhesion. We remove all degraded material, seal every penetration, then spray. The blower-door test proves the difference.
- Uninsulated wall cavities ignored in favor of attic-only treatment. This is the pattern we see most often in Terrell Hills: a homeowner sprays the attic, the west bedroom still hits 102°F in July, and thermal imaging reveals the brick veneer is radiating heat through an empty 2×4 cavity. Attic work alone cannot fix this.
- Rim joists and north-facing exterior walls left untreated. The February 2021 freeze burst pipes in these exact locations across Terrell Hills’s mid-century homes. Closed-cell foam at the rim joist and any accessible north wall cavity is the minimum retrofit for freeze resilience.
- Permits pulled through San Antonio or Bexar County instead of Terrell Hills city hall. This stops jobs at inspection. Terrell Hills is a self-governing enclave with its own building department, and our Spray Foam Insulation in Terrell Hills process includes correct permitting from the start.
Pricing for Spray Foam Insulation in Terrell Hills, TX
| Application | Typical Range (Terrell Hills) | Notes |
|---|---|---|
| Open-cell attic (flat ceiling, 2,400 sq ft home) | $3,200 - $4,800 | Includes removal of degraded original insulation, air sealing, R-38 equivalent |
| Closed-cell rim joist (typical ranch) | $1,400 - $2,200 | 2-inch minimum, freeze-protection priority |
| Closed-cell wall cavities (west/south walls, injected) | $2,800 - $4,500 | Requires drilling access; price varies with cavity condition |
| Closed-cell roof deck (cathedral or conditioned attic) | $4,200 - $6,800 | R-21 minimum at 3.25 inches; full air barrier |
| Garage ceiling (2-car, open joist) | $1,800 - $2,800 | Open-cell; finished ceiling adds labor |
What moves the price: the condition and volume of existing insulation to remove, accessibility of wall cavities for injection, whether the roof deck or attic floor is being sprayed, and the extent of air sealing required before foam application. Every Terrell Hills job gets a Written Price Before Any Work Starts, with the scope, warranty, and blower-door target documented in writing. We also offer a Free Second Opinion on any competing written estimate. Call (830) 529-7780 for exact numbers on your home.
We Also Serve Cities Near Terrell Hills

Our crews work throughout the San Antonio metro area, including our Spray Foam Insulation service in Boerne, Fair Oaks Ranch, Scenic Oaks, and Helotes. Each of these markets has its own housing stock characteristics and, where applicable, local permitting requirements. Dispatch and scheduling for Terrell Hills are coordinated from our San Antonio office.
Serving Terrell Hills, TX - Our Local Coverage Area
We’re based in the Terrell Hills 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 Terrell Hills

You need a permit from Terrell Hills city hall specifically; San Antonio and Bexar County have no jurisdiction here. Terrell Hills is a self-governing enclave completely surrounded by San Antonio, with its own municipal building department and inspection schedule. We pull these permits as part of our standard scope, and we know the inspectors who evaluate spray foam in the city’s 1940s-1970s custom homes. Call (830) 529-7780 and we’ll confirm the current permit fee and timeline for your specific project.
No, and any contractor who proposes that is skipping the step that determines whether the foam will perform. Original rock wool in Terrell Hills homes has typically settled to R-5 or below, and it hides air leaks at top plates, can lights, and duct penetrations that must be sealed before insulation goes in. We remove all degraded material, perform air sealing with documented blower-door verification, then spray. The old rock wool goes to disposal; the new foam goes on a clean, sealed substrate.
Because the wall cavity is likely empty, and in Terrell Hills’s 1950s-60s brick homes, many were built with no wall insulation whatsoever. Brick thermal mass was considered sufficient by South Texas builders of that era, but it cannot compensate for a 2×4 cavity that conducts afternoon solar gain directly into the room. We verify this with thermal imaging; if the cavity is empty, we inject open-cell foam to achieve R-13.5 in the wall. Attic-only upgrades in these homes routinely fail to solve west- and south-facing room overheating.
Attic spray foam helps, but the critical vulnerabilities in Terrell Hills’s mid-century homes are the rim joists and any exterior-facing north wall cavities, which often had near-zero insulation during the 2021 freeze. We prioritize closed-cell foam at rim joists to a minimum 2-inch thickness, and we inspect accessible north walls for injection. The attic is part of the solution; the lower envelope is where the pipes actually froze. Our written scope specifies which assemblies we’re treating and why.
Open-cell is lighter, less expensive at $2.80-$3.60 per board foot, and permeable to moisture vapor, making it suitable for attic floors and wall cavities in vented assemblies. Closed-cell is denser, rigid, more expensive at $4.50-$5.40 per board foot, and forms a vapor barrier, making it necessary for rim joists, roof decks, and any location where bulk water or freeze protection is a concern. In Terrell Hills’s older brick homes, we often use both: open-cell in wall cavities for cost-effective R-value, closed-cell at rim joists and roof decks for air sealing and moisture control. The specific mix is written into your scope before work starts. Call (830) 529-7780 for a free estimate with exact product specification.
Written by Wes Okafor, Owner at Topside Attic Insulation Boerne, serving Terrell Hills since 2016.