Icynene Attic Air Sealing: The Schertz Owner’s Guide
We stock and install Icynene-compatible attic air sealing components in Schertz, with most residential jobs running between $1,800 and $3,400 installed, depending on attic square footage and penetration count. Same-day service is available when you call before noon, and we carry Icynene-compatible sealants, gasket materials, and spray-foam touch-up kits on every truck. Most Schertz homeowners discover their attic air sealing has failed when utility bills spike during July and August despite the AC running constantly, or when they notice hot attic air pushing through can-light trim during our 100°F stretches.
Which Icynene Models This Applies To
Icynene’s open-cell and closed-cell spray foam systems seal the building envelope differently, and the air-sealing layer we’re addressing sits at the attic floor plane, not the roof deck. If your Schertz home was built between 2015 and 2022 and has Icynene open-cell under the roofline, you likely have a hybrid system where the spray foam seals the rafter bays but the attic floor still needs top-plate and penetration sealing to isolate the conditioned space below.
Check your Icynene installation paperwork for the series designation: LD-C-50 (open-cell) and MD-C-200 (closed-cell) are the two most common in the Schertz market. The label is usually on a beam tag near the attic access hatch or on the electrical panel door if your builder documented the envelope work. We don’t need the exact batch number, but we do need to know whether the foam was applied to the roof deck or the floor, because that determines whether we’re sealing against conditioned attic air or sealing the floor plane below an unconditioned vented attic.
Topside Attic Insulation Schertz is an independent service provider, not affiliated with Icynene. For OEM-grade compatibility, we source Icynene-compatible acrylic sealants and one-component foam from the same supply chain used by certified Icynene installers. Aftermarket equivalents exist, but in Schertz’s heat-cycling climate, we’ve seen generic sealants chalk and crack within 18 months on south-facing top plates. We stock both and will show you the spec sheet difference before we open a tube.
Signs Your Icynene Attic Air Sealing Is Failing

- Dust streaks around ceiling registers or can-light trim. This means conditioned air is escaping into the attic through gaps in the top-plate seal, carrying dust that deposits on the ceiling surface. In Schertz, we see this most in homes where the original builder skipped sealing the partition-wall top plates before blowing insulation.
- Hot spots on the ceiling during afternoon hours, especially in second-floor rooms. When attic air sealing fails, convective loops pull 140°F attic air down through gaps around duct boots and electrical penetrations. Your insulation doesn’t stop air movement, it only slows conductive heat transfer.
- Ice damming or heavy frost on roof sheathing in winter. Warm, moist interior air leaking through failed seals condenses on the underside of cold roof decking. Even in Schertz’s mild winters, a week of sub-40°F nights is enough to show this pattern if the seal is compromised.
- Insulation that looks disturbed or settled unevenly near eaves and penetrations. Air moving through gaps carries fine insulation particles with it, creating depressions or bare spots. This is a telltale sign we check for first on every Schertz attic inspection.
- Blower-door test showing little improvement after insulation upgrade. If you added insulation but your home still tests above 3,000 CFM50, the air leaks were never sealed. We see this in Sedona subdivision homes where a previous contractor blew fiberglass over unsealed top plates and called it done.
Replacement Cost & What’s Included
Most Icynene attic air sealing jobs in Schertz run between $1,800 and $3,400, with the lower end covering a single-story home under 2,000 square feet with standard penetration counts, and the upper end hitting two-story homes with complex HVAC routing, multiple bath-fan penetrations, or recessed can lights requiring gasketed covers. The price includes labor, Icynene-compatible sealant, one-component foam for small gaps, fire-rated caulk for top plates, and rigid foam blocking at large penetrations.
What drives the range: attic accessibility (scissor truss vs. conventional), penetration density, and whether we need to remove existing insulation to access the leaks. We price by the linear foot of top plate and per-penetration count, not by attic square footage, because a 1,500-square-foot home with 40 can lights takes longer than a 2,500-square-foot home with surface-mounted fixtures. Every job gets a written price before any work starts, under Haven Standard Clause 1, and includes a Documented Photo Record and before-and-after blower-door test so you can verify the result.
Seal the leaks first. Then insulate. The attic doesn’t care how thick the insulation is if the air is still moving through it.
DIY or Call Us?

There’s a short list of what a Schertz homeowner can safely check: look for visible gaps around the attic access hatch, pull back insulation at a few top plates to see if black gaps show daylight, and note any dust streaks on the ceiling below. Do not, however, attempt to seal around recessed can lights yourself unless you know whether they’re IC-rated (insulation contact) and what fire-rated caulk rating your jurisdiction requires. Guessing wrong creates a combustion hazard.
Where DIY goes wrong: walking the attic floor without knowing where the ceiling drywall is supported, compressing insulation while trying to seal underneath it, and using the wrong sealant for the substrate. We’ve found latex caulk slathered over dusty OSB in Schertz attics, already peeling at the edges. The blower-door test is the only way to verify your work, and the fan assembly runs about $4,000. Call (830) 402-5240 and we’ll test, seal, and document it properly.
FAQs
Properly installed acrylic sealant on clean substrates lasts 15 to 20 years in our climate, but one-component foam degrades faster, typically 7 to 10 years before re-checking is warranted. Schertz’s combination of 140°F attic peaks and occasional hard freezes accelerates thermal cycling stress on flexible sealants. We recommend a blower-door re-test at year 5 to catch degradation before it shows on your utility bill. Call (830) 402-5240 to schedule - estimates are free.
Localized repairs are possible if the failure is isolated to a few penetrations or a single top-plate section, but if the original work was skipped entirely or done with incompatible materials, spot-fixing leaves adjacent leaks unaddressed. We evaluate this with a smoke-pencil walk during the blower-door test to map active leak paths. Call (830) 402-5240 and we’ll show you the thermal-imaging summary so you can decide repair scope with actual data.
A typical Schertz single-story home takes one crew day, with two-story or complex attics running into a second day. We don’t start insulation until the sealing is verified with a mid-process blower-door reading, so the timeline includes testing, not just application. You’ll get a printed scope with the hour-by-hour plan before we begin.
Yes. Every Topside Attic Insulation Schertz truck carries Icynene-compatible acrylic sealant, fire-rated caulk, one-component foam, gasketed can-light covers, and rigid foam board for blocking large penetrations. We also stock Reflectix components for radiant-barrier integration where the attic design calls for it. If your Icynene system needs a manufacturer-specific touch-up, we source from the same distribution channel and document the batch number in your job record.
Ready to stop paying to air-condition your attic? Call (830) 402-5240 for a free estimate. We’ll run the blower-door test, show you the leak map, and give you a written price before any work starts. Every job closes with a Documented Photo Record and your before-and-after CFM50 numbers, because in Schertz, you should be able to prove what you paid for.
Written by Wes Okafor, Owner, Topside Attic Insulation Schertz at Topside Attic Insulation Schertz, serving Schertz and nearby areas.