Johns Manville Insulation Removal & Replacement in Seguin: What to Know First
We provide independent Johns Manville insulation removal and replacement in Seguin, with most attic jobs completed in one day and a written price delivered before any work starts. Our crew removes failed or contaminated JM batts, blown-in, and board products, then replaces with matched or upgraded material - documented with before-and-after photos and, on applicable jobs, blower-door readings that show the actual air-leakage reduction. This page is for Seguin homeowners who have Johns Manville insulation that has settled, gotten wet, been compromised by rodents, or simply reached the end of its functional life. Call (830) 549-6646 for a free written estimate - the price we put on paper is the price you pay.
How Johns Manville Products Fail - and How We Fix Them
- JM Spider blown-in fiberglass settles below labeled R-value in Seguin’s humidity. Spider - the loose-fill product that Johns Manville markets as “self-supporting” - loses loft in attics where summer attic temperatures exceed 140°F and relative humidity cycles hard. We’ve pulled Spider that had compressed from 14 inches to 8 inches in homes near Guadalupe Regional Medical Center, delivering R-19 performance where R-38 was specified. We remove it completely and replace with either fresh blown-in fiberglass at proper depth or switch to cellulose, which holds loft better in our climate.
- JM Formaldehyde-free batts sag in open-floor attics with active air leaks. The batts without binder resin are softer and more prone to falling away from top plates and kneewalls when attic air moves through gaps. We find this especially in 1970s and 1980s Seguin construction where original batts were stuffed without air sealing. Our fix: remove the fallen material, seal every top plate and penetration with foam and caulk, then reinstall with proper friction fit or netting.
- JM polyiso board insulation traps moisture when the facing fails. The foil or fiberglass facings on JM AP Foil-Faced and similar boards delaminate at fasteners and edges after 15-20 years. Once the facing is compromised, humid Hill Country air reaches the foam core; we’ve cut open boards that were wet to the center in unvented cathedral ceilings near the Seguin River. We remove the full board assembly, inspect and dry the cavity, and replace with new polyiso or switch to closed-cell spray foam if the assembly allows.
- JM mineral wool batts degrade from rodent urine saturation. The dense, fire-resistant batts - ComfortTherm and similar lines - don’t compress easily, but they do absorb urine and hold odor. In Seguin attics with roof rat activity near wooded lots, we’ve removed mineral wool that registered high on moisture meters despite feeling dry to the touch. We remove, HEPA-vacuum the cavity, sanitize, rodent-proof with steel mesh at all entry points, then replace with fresh material.
- JM Kraft-faced batts develop mold on the paper vapor retarder. The asphalt-impregnated paper facing is a food source when attic humidity stays above 60% for extended periods, which happens in Seguin during spring and fall when outside air sits below dew point against cooled drywall. We remove affected batts, treat framing with antimicrobial where needed, improve ventilation or air sealing depending on what the attic needs, and replace with unfaced batts plus proper ventilation strategy.
Our Johns Manville Insulation Removal & Replacement Process

- 1
Call and scope. A live person answers at (830) 549-6646. We ask what JM product you have if you know it, what’s driving the call (odor, high bills, visible damage), and schedule a site visit.
- 2
On-site inspection and written price. We identify the JM line, measure depths, check for contamination or moisture, and photograph everything. You get a flat price, written scope, and written warranty before anyone lifts a tool - Haven Standard Clause 1.
- 3
Air sealing first, always. Before new insulation touches anything, we seal top plates, can lights, plumbing and electrical penetrations, and the attic hatch with foam, caulk, and rigid baffles. The blower-door test - a pressurization diagnostic that measures how much conditioned air your house loses per hour - gives us the baseline.
- 4
Removal and disposal. We bag old JM material, HEPA-vacuum the deck, and haul everything. Contaminated material gets documented with photos for your records.
- 5
Replacement and verification. New insulation goes in to spec depth or R-value. We run the blower-door test again and hand you the printed pre- and post-installation report with ACH50 numbers. The report goes home with you - the numbers do the talking.
- 6
Cleanup and 365-Day Done Right Promise. We leave the attic cleaner than we found it. If anything’s not right, we make it right - backed by the written scope you already have.
Before
AfterWhat Johns Manville Insulation Removal & Replacement Costs in Seguin
Most Johns Manville insulation removal and replacement jobs in Seguin run between these ranges:
| Scenario | Typical Range |
|---|---|
| Partial JM batt removal and replacement (one area, no contamination) | $1,400 - $2,600 |
| Full attic JM blown-in removal and replacement with air sealing | $3,200 - $5,800 |
| JM board insulation removal in cathedral ceiling (per section) | $2,800 - $4,500 |
| Contaminated JM removal with sanitizing and rodent proofing | $3,500 - $6,200 |
| Add blower-door testing with printed report | $350 - $450 (included on most full jobs) |
What moves the price: attic square footage, accessibility (scuttle vs. pull-down stairs vs. cut new access), contamination level, whether the original JM product was installed over an unsealed attic floor (which we fix first), and your choice of replacement material. We also source from Owens Corning, Knauf, Rockwool, CertainTeed, and others - no proprietary lock-in, so we match the right product to your assembly. Call (830) 549-6646 for a free written estimate with exact numbers for your house.
Why Seguin Homeowners Call Topside Attic Insulation Seguin for Johns Manville Work

We’re an independent Johns Manville service provider - not affiliated with or authorized by the manufacturer - which means we work for you, not a brand rep. Wes Okafor, our owner and lead technician, learned thermal envelope science at Triton College in River Grove, IL, and has spent over two decades in insulation work. His crew has served Seguin and the Hill Country edge long enough to know that older attic framing near Guadalupe Regional Medical Center almost always hides air leaks that need sealing before new insulation goes in.
We publish before-and-after blower-door numbers on every applicable job, deliver a Documented Photo Record on every visit, and back everything with the 365-Day Done Right Promise. Calls are answered by a live person 24/7. We also service Reflectix and other brands, so if your assembly calls for a material switch, we can handle it without calling a second contractor.
FAQs
No - the original JM product warranty on insulation materials is typically limited to manufacturing defects and does not cover removal for cause (damage, contamination, or end of service life). As an independent Johns Manville service provider, we document the condition of your existing material with photos before removal, which protects you if any defect claim arises. Call (830) 549-6646 and we’ll review what documentation you have.
Most full attic jobs in Seguin are completed in one day, with larger or contaminated jobs running into a second day. We don’t rush the air-sealing phase - that’s what makes the replacement perform. You’ll get a written schedule with your price before work starts.
We can match JM batts and loose-fill from current production lines. Discontinued JM products get replaced with equivalent or upgraded material from JM or another manufacturer - Owens Corning, Knauf, Rockwool, depending on what’s right for your assembly. We never lock you into a single brand.
Almost never, if the old material is compressed, contaminated, or wet. Adding over compromised insulation traps moisture and hides problems. We remove it, fix the underlying issue, and start clean. The written price we give you covers the full scope - no surprise add-ons after we open the attic.
We keep slots open for urgent situations - active roof leaks into insulation, rodent contamination with occupants sensitive to allergens, that sort of thing. A live person answers (830) 549-6646 24/7, and we’ll tell you honestly if we can get there today or if first thing tomorrow is the realistic option.
Written by Wes Okafor, Owner & Lead Insulation Technician, Topside Attic Insulation Seguin at Topside Attic Insulation Seguin, serving Seguin and nearby areas.