Johns Manville Blown-In Insulation in Schertz: What to Know First
We provide independent Johns Manville blown-in insulation service in Schertz, typically completing attic jobs in one day with a written price delivered before any work starts. Most Johns Manville blown-in cellulose or fiberglass top-ups in the Schertz corridor run between $1,800 and $3,400 for a standard 1,500-square-foot attic, depending on existing depth and air-sealing needs. Call (830) 402-5240 for a free estimate with a written scope.
This page is for homeowners who already have Johns Manville insulation in their attic or walls and need a top-up, replacement, or dense-pack installation. If you’re seeing uneven temperatures, rising energy bills, or you bought a home in Sedona, Willow Grove, or another Schertz subdivision built between 2015 and 2020, there’s a fair chance your builder spec’d Johns Manville blown-in fiberglass or cellulose. We’re not affiliated with or authorized by Johns Manville - we’re an independent Johns Manville service provider - which means we work on what you actually have, not what a manufacturer’s marketing says you should buy next.
How Johns Manville Products Fail - and How We Fix Them
- Climate Pro Blown-In Fiberglass settles below labeled R-value in Schertz’s heat. The 140°F attic temps we measure in Sedona and along FM 1518 accelerate binder breakdown in JM’s fiberglass batts and loose-fill. Over 7-10 years, what was sold as R-38 compresses to R-26 equivalent. We remove the settled material, air-seal the top plates and can-light penetrations, then reinstall to true depth with a depth-stick photo log.
- Attic Pro Blown-In Cellulose develops voids near eaves where baffles failed. Johns Manville’s cellulose performs well when contained, but Schertz’s wind-driven rain events push moisture past compromised baffles. The cellulose wicks water, clumps, and creates cold spots. We inspect every baffle, replace water-damaged sections, and dense-pack the eave zone with fresh material rather than blowing over the clumps.
- Wall-Safe loose-fill in 2×4 walls slumps in balloon-framed sections. Older Schertz homes near the original downtown core, plus some 2010s builds with irregular framing, see JM Wall-Safe settle in tall wall cavities. We diagnose this with thermal imaging - the thermal-imaging summary we provide shows exactly where - then dense-pack those cavities at higher density (3.5 lbs/cubic foot) to lock the material in place.
- Formaldehyde-free fiberglass irritates during disturbance. JM’s formaldehyde-free binders are safer for long-term occupancy, but the alternative binder can become airborne more readily during top-up work. We run negative air and sealed-cavity extraction during removal, then wet-spray the new blow to control dust. The crew wears respirators; you don’t smell anything downstairs.
- Multi-layer installs hide air leaks between old and new material. When a previous contractor blew new JM over old without sealing first, the interface becomes a convection highway. We strip to the deck, seal every penetration with fire-rated foam and gasketed covers, then reinstall. The blower-door test - pressurization reading before and after - proves the fix: we’ve seen 4,200 CFM50 drop to 2,100 on Schertz jobs where this was the primary failure.
Our Johns Manville Blown-In Insulation Process

- 1
Call and scheduling. A live person answers 24/7. We book a site visit in Schertz, usually within 48 hours. You get a text when the technician is en route - Haven Standard: Arrive on schedule.
- 2
Pre-work inspection and blower-door test. We pressurize the house and measure CFM50 baseline. Then we thermal-scan the attic, mark every penetration, and photograph existing Johns Manville product labels where visible. Wes Okafor, our owner, grew up on Chicago’s South Side and learned building science at Richard J. Daley College; he’s been in attics for two decades and won’t let a crew start if the pre-work inspection turns up something that needs addressing first.
- 3
Written price before any work starts. Flat price, written scope, written warranty - Haven Standard Clause 1. No work begins until you have all three in hand. Free Second Opinion on any written estimate if you want us to read a competing quote with you.
- 4
Air sealing first, then insulation. Seal the leaks first. Then insulate. The attic doesn’t care how thick the insulation is if the air is still moving through it. We seal top plates, wire penetrations, can lights, and chimney chases with fire-rated materials. The crew documents every sealed point with photos.
- 5
Blown-in installation to spec. We install Johns Manville, Owens Corning, Knauf, or another specified material to the depth and density on the written scope. Depth-stick photos every 100 square feet. For dense-pack wall work, we verify cavity fill with thermal imaging in real time.
- 6
Post-work verification and documentation. Blower-door test repeated. Printed thermal-imaging summary. Post-install depth-stick photo log. Written warranty and 365-Day Done Right Promise delivered before the crew leaves. Every job since 2016 - over 9,000 homes - has closed with this documentation.
What Johns Manville Blown-In Insulation Costs in Schertz
| Job Type | Typical Range | What Moves the Price |
|---|---|---|
| Attic top-up (existing R-19 to R-38) | $1,800 - $2,600 | Attic square footage, access difficulty, whether air sealing is needed |
| Attic removal + reinstall to R-38 | $2,800 - $4,200 | Volume of settled material, rodent damage, deck repairs |
| Dense-pack wall insulation (per 1,000 sq ft wall) | $3,200 - $4,800 | Cavity accessibility, balloon framing, exterior finish type |
| Crawl space encapsulation + rim joist | $4,500 - $7,500 | Crawl height, existing vapor barrier condition, pest damage |
These are real Schertz-market numbers for homes we work on - Sedona, Willow Grove, the corridor near I-35 and FM 3009. Price goes up if we find failed baffles, moisture damage, or unsealed penetrations that weren’t visible from the access hatch. Price goes down if your existing Johns Manville is in good shape and only needs a targeted top-up. We don’t guess; we inspect, then write the price. Call (830) 402-5240 for a free estimate - the written scope comes with it.
Why Schertz Homeowners Call Topside Attic Insulation Schertz for Johns Manville Work

We’ve been working the Schertz corridor for several years now, including jobs where summer attic temps push past 140°F before we start. Our sequencing matters: blower-door test first, air-sealing second, blown-in third. Adding R-38 over an unsealed attic floor is money spent on the wrong problem, and we won’t do it.
The 365-Day Done Right Promise applies to every completed job. Background-checked, uniformed technicians. Calls answered by a live person, 24/7. We also service Reflectix and other brands, so if your job involves mixed materials or a radiant barrier layer, we don’t need a second contractor.
Every homeowner receives the same documentation: written price before work starts, printed thermal-imaging summary, post-install depth-stick photo log, and before-and-after blower-door numbers on applicable jobs. That’s been the standard since 2016. It’s not an upgrade.
FAQs
No. Johns Manville’s product warranties cover material defects, not who installs or services them. Manufacturer warranties remain valid as long as the product itself is genuine Johns Manville; our documentation supports any future claim you might need to file. Call (830) 402-5240 if you want us to verify what you have and walk through the warranty terms.
We can source current Johns Manville lines - Climate Pro, Attic Pro, Wall-Safe - or specify an equivalent from Owens Corning, Knauf, or another manufacturer we carry. We don’t lock you into proprietary products. The written scope names exactly what goes in, by brand and R-value, before anyone lifts a tool.
Repair is cheaper when the material is dry, evenly distributed, and only thin in spots - typically $1,800-$2,600 for a Schertz attic top-up. Removal and replacement runs $2,800-$4,200 but is necessary when there’s moisture damage, rodent contamination, or settled fiberglass that’s lost its labeled R-value. We inspect and tell you which category you’re in, with photos.
Most attic jobs finish in one day. Dense-pack wall work or full removal-and-replace may run two days. We schedule within 48 hours of your call, and a live person answers 24/7 - no callback windows measured in business days. Call (830) 402-5240 to book.
A printed thermal-imaging summary, post-install depth-stick photo log, before-and-after blower-door readings on applicable jobs, your written warranty, and the 365-Day Done Right Promise. This is standard on every job, not available on request. You’ll know what leaving looks like before we arrive.
Written by Wes Okafor, Owner, Topside Attic Insulation Schertz at Topside Attic Insulation Schertz, serving Schertz and nearby areas.