Fast, Reliable Spray Foam Insulation Across Kirby
Spray foam insulation in Kirby runs strictly as retrofit work on 1950s-1970s slab-on-grade ranch homes, with most attic jobs falling between $2,800 and $5,400 depending on whether we’re treating the roof deck, rim joist, or both. Our crews dispatch from the San Antonio office and typically reach Kirby properties within 30-45 minutes. Call (830) 402-5240 for a written price before any work starts.
Kirby’s one-square-mile footprint is fully built out and landlocked by San Antonio, so every job we do here is on aging housing stock where original fiberglass batts have spent 50-plus years in attic heat that routinely hits 140-150°F. That context matters. A crew that treats Kirby like any other Bexar County suburb will miss the specific failure modes these homes present: un-insulated wall cavities, rim joists open to alley-side crawlspaces, and roof decks that need to be sealed during the narrow window when a reroof crew has already exposed them.
Why Topside Attic Insulation Schertz Is Kirby’s Preferred Spray Foam Insulation Company
We’ve sealed and insulated more than 9,000 homes since 2016, and Kirby’s compact housing stock is familiar territory. Our Spray Foam Insulation team knows the difference between a 1962 tract ranch off Ackerman Road and a 1974 build near the old Kirby city limits, and we adjust our material specs accordingly.
Kirby homeowners review us specifically for showing up during reroof windows and documenting the result. Our three-star reviews get read as carefully as our five-stars, and they consistently mention the same thing: we deliver the written scope, the blower-door numbers, and the photo record we promised. No voicemail loops, no callback windows measured in business days. A live person answers at (830) 402-5240 24/7.
Response time to Kirby averages under 45 minutes from dispatch. That’s not a marketing claim; it’s a function of geography. Kirby sits entirely inside San Antonio’s loop, with no rural stretch to cross. When a reroof crew calls us in because the shingles are off and the attic deck is exposed, that proximity determines whether we hit the window.
Our Spray Foam Insulation Services in Kirby
Closed-Cell Spray Foam
Closed-cell spray foam is our primary specification for Kirby’s exposed roof decks and rim joists. At roughly 2.0 lbs per cubic foot, it adds structural rigidity to 1960s decking that has warped through decades of heat cycling, and its 6.0+ R-value per inch lets us hit code-minimum R-38 in the shallow rafter bays common to these ranch homes. On a typical Kirby attic with 2×6 rafters, we can achieve R-38 in a single 6-inch pass without furring down the ceiling.
The exotherm risk is real on these old decks. We never apply closed-cell thicker than 2 inches per lift, and we monitor deck surface temperature between passes. A crew that sprays too thick, too fast will bow the sheathing and crack the flashing points before the roofer returns. We’ve seen it on Kirby jobs where we were called to fix another contractor’s work.
Open-Cell Spray Foam
Open-cell spray foam, lighter and more vapor-permeable at 0.5 lbs per cubic foot, is what we use for attic-side walls and larger cavity fills where we want the assembly to breathe. In Kirby’s hot-humid Climate Zone 2, open-cell on the attic side of a knee wall lets moisture drive outward rather than trapping it against the gypsum.
We do not use open-cell as a single-pass solution over old fiberglass batts. The bond fails. In Kirby’s attics, where settled batt residue is almost always present, we remove or thoroughly vacuum the existing material before any foam goes in. Skipping this step is how you get delamination within two seasons.
Rim Joist Spray Foam
The rim joist is where Kirby’s alley-loaded lots create a specific problem. These 1960s slab ranches often have rim joists open to narrow crawlspaces or utility alleys, creating a direct air path between outside and the conditioned floor plane. In winter, this pulls cold air across the slab edge; in summer, it pressurizes the living space with attic-temperature air.
We treat rim joists with closed-cell foam, typically 2-3 inches, to create both an air seal and a thermal break. On Kirby’s tight lots, access means working around AC condensers, alley gates, and sometimes neighbor fences. Our crews carry portable rigs sized for these constraints.
Garage Ceiling Spray Foam
Garage ceiling foam in Kirby is usually tied to a larger attic job. These ranch homes often have attached garages with un-insulated ceilings that communicate directly with the attic space. We treat the garage ceiling as part of the thermal envelope when the homeowner is already investing in the main attic, using open-cell for cost efficiency in the larger cavity and closed-cell at any rim joist or header that spans the garage-to-house junction.
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 Kirby
We source spray foam systems from Icynene, Demilec, and Owens Corning, among others, and we do not lock into proprietary products. For Kirby’s pre-1970 housing stock, we most often quote Icynene and Demilec closed-cell systems for roof deck and rim joist work, with open-cell specifications from the same manufacturers for attic-side walls. We stock local inventory for Kirby jobs to avoid the lead times that can kill a reroof window. When a roofer calls on Tuesday saying the deck is exposed and dry, we need material on the truck by Wednesday morning.
Common Spray Foam Insulation Problems We See in Kirby Homes
- Low-density open-cell sprayed directly over settled batts without removal. In Kirby’s Zone 2 attics, foam bonded to moisture-wicked fiberglass traps water vapor at the interface. The bond fails within a season or two, and the homeowner is left with a delaminated mess that costs more to remove than the original job.
- Rim joist skipped on alley-loaded lots. The crawlspace or utility alley is three feet from the living room, and the rim joist is wide open. Crews focused only on the attic deck miss this bypass completely. The house still leaks, and the floor still runs cold in January.
- Closed-cell applied too thick in a single lift on warped 1960s decking. The exotherm reaction generates enough heat to bow sheathing that already has 60 years of thermal cycling behind it. Cracked decking means delayed reroof completion and sometimes re-flashing.
- Moisture not verified before foam application. Kirby’s attics hit 140-150°F regularly, but they also cool rapidly after rain. We moisture-map the deck and existing insulation before quoting. Foam on wet substrate is a guaranteed callback.
Pricing for Spray Foam Insulation in Kirby, TX
Most spray foam jobs in Kirby fall into these ranges based on what we’re treating:
| Application | Typical Range |
|---|---|
| Open-cell attic (roof deck, 6-8 inches) | $2,800 - $4,200 |
| Closed-cell attic (roof deck, 3-4 inches) | $3,600 - $5,400 |
| Rim joist only (closed-cell, typical Kirby slab ranch) | $1,400 - $2,200 |
| Combined roof deck + rim joist | $4,200 - $6,800 |
| Garage ceiling add-on | $900 - $1,600 |
These are Kirby-specific ranges for 1,200-1,800 square foot ranch homes, the dominant housing type here. Actual price depends on accessible square footage, existing material removal requirements, and whether we hit a reroof window that simplifies deck prep. We deliver a written price before any work starts, always, under Haven Standard Clause 1. Free second opinion on any competing written estimate. Call (830) 402-5240 for exact numbers on your property.
We Also Serve Cities Near Kirby
Our crews work throughout the I-35 and Loop 1604 corridor, including Kirby neighbors in Schertz, Cibolo, Universal City, and Selma. Dispatch and scheduling run from our San Antonio office. Same written-price standard, same documented photo record, same 365-Day Done Right Promise.
Serving Kirby, TX - Our Local Coverage Area
We’re based in the Kirby 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 Kirby
We prefer the deck fully exposed and visually dry before we mask and spray, which usually means coordinating for the day after tear-off completes. On a 1962 slab-on-grade ranch off Ackerman Road, our crew arrived mid-reroof to find the original 3-inch fiberglass batts torn out, un-insulated stud bays behind the knee wall, and a rim joist open to the alley-side crawlspace. We masked and applied closed-cell spray foam on the exposed roof deck and rim joist, then finished with open-cell on the attic-side wall. The key is timing: we need a dry deck, clear access, and the roofer’s schedule locked before we commit. Call (830) 402-5240 to coordinate windows.
For walls with intact drywall, we typically recommend dense-pack cellulose or injection foam through discrete exterior holes rather than spray foam, which requires cavity access. However, if the wall is already open during a reroof or addition, we will spec open-cell foam for the cavity fill. In Kirby’s un-insulated tract construction, the bigger thermal bypass is usually the attic and rim joist, not the walls. We address those first and measure the result with a blower-door test before recommending wall work. Free estimate at (830) 402-5240.
Yes. The rim joist is a separate thermal bypass. In Kirby’s alley-loaded lots, the rim joist often communicates with a narrow crawlspace or utility passage that is outside the attic envelope. Open-cell in the attic does not seal this path. We spec closed-cell at the rim joist, 2-3 inches, to create both an air seal and a thermal break at the slab edge. Skipping it leaves the floor plane leaking.
Spray foam on the roof deck reduces the attic to a semi-conditioned space, dropping surface temperatures significantly and reducing the delta-T that drives heat into the living space. On that July afternoon at the Ackerman Road job, the unvented attic was still reading triple digits, but the deck surface dropped out of the 140-150°F band and the return-side of the house stopped pulling attic air into the living space. The real win is air sealing: a blower-door test before and after shows the reduction in conditioned air loss, which is what you pay the utility for.
Our rigs are sized for urban access, and we coordinate with homeowners on alley gate codes, neighbor notifications, and condenser clearances before arrival. On the tightest Kirby lots, we stage material in the driveway and run hose through the garage or side yard rather than blocking the alley. We text when the technician is en route, with a named technician and ETA, under Haven Standard: Arrive on schedule. Call (830) 402-5240 to walk through access on your specific property.
Written by Wes Okafor, Owner at Topside Attic Insulation Schertz, serving Kirby since 2016 under The Haven Standard.