Johns Manville Crawl Space Encapsulation & Vapor Barrier Nationwide

Johns Manville Crawl Space Encapsulation & Vapor Barrier in New Braunfels: What to Know First

We provide independent Johns Manville crawl space encapsulation and vapor barrier service in New Braunfels, with most jobs scheduled within 48 hours and completed in a single day. A typical crawl space encapsulation runs between $3,200 and $6,800 depending on square footage, existing moisture damage, and whether the home needs full perimeter drainage matting or just a vapor barrier upgrade. Every job starts with a written price before any work begins, and we publish before-and-after blower-door numbers so you see the air-sealing result in CFM50, not just a promise.

Call (830) 243-6352

This page is for homeowners in New Braunfels who have Johns Manville insulation products in their crawl space and need encapsulation, vapor barrier replacement, or moisture control. We also service Reflectix and other major brands. Call (830) 243-6352 for a free estimate with a written scope.

How Johns Manville Products Fail - and How We Fix Them

• JM Spider blown-in fiberglass settling in damp crawl spaces. Spider is engineered to cling without netting, but in New Braunfels crawl spaces with seasonal humidity spikes above 70%, the binder breaks down and the material compacts to half its installed thickness. We remove the settled product, install a sealed vapor barrier first, then replace with JM Climate Pro or an equivalent high-density batt that maintains R-value at 75% relative humidity.
• Formaldehyde-free batts wicking moisture from unsealed earth floors. Johns Manville’s formaldehyde-free batts use a plant-based binder that degrades faster than phenolic binders when it cycles through wet-dry conditions. In Comal County homes near the Guadalupe River corridor, we’ve found batts that test at R-6 despite being labeled R-19. We extract the degraded material, remediate the moisture source, and reinstall only after the crawl space is fully encapsulated.
• Poly vapor barrier delamination in JM pre-cut crawl space kits. The 6-mil poly included in some JM crawl space packages becomes brittle after 5-7 years in Texas Hill Country temperature swings, cracking at seams and perimeter stakes. We upgrade to a 12-mil reinforced polyethylene with woven scrim, taped at all seams with butyl tape, and mechanically fastened to foundation walls with masonry anchors, not landscape staples.
• JM AP Foil-faced polyiso board losing adhesion on crawl space walls. The foil facing provides a vapor barrier on one side, but in vented New Braunfels crawl spaces, condensation forms on the cold side during shoulder seasons and the board pulls away from block walls. We switch to a conditioned crawl space approach: seal vents, install a dehumidifier, and use mechanically fastened foam board with proper drainage plane details.
• Insulation contact (IC) can lights creating thermal bypasses in crawl space ceilings. When Johns Manville batts are pushed against non-IC-rated fixtures in the crawl space ceiling, the compressed fiberglass creates a hot spot that drives moisture migration. We mark every penetration, install fire-rated covers, then air-seal with firestop caulk before reinstalling insulation to full loft.

Our Johns Manville Crawl Space Encapsulation & Vapor Barrier Process

1. 1
   Moisture and air-leakage assessment. We measure relative humidity, wood moisture content, and run a blower-door test to quantify how much conditioned air the house is losing through the crawl space. The number on the blower-door printout tells you what the insulation did. Everything else is just talk.
2. 2
   Written scope and price. We specify which Johns Manville products stay, which get replaced, and what aftermarket materials we recommend. You get a flat price, a written warranty, and a documented photo record before anyone lifts a tool.
3. 3
   Material prep and moisture remediation. We source JM materials from our supplier network or specify equivalent-performance alternatives when JM lead times run long. Standing water gets addressed with drainage matting and sump placement if needed.
4. 4
   Encapsulation and air sealing. Vapor barrier goes down wall-to-wall, seams taped, perimeter sealed to walls. Top plates, plumbing penetrations, and electrical chases get sealed with closed-cell foam or fire-rated caulk depending on application.
5. 5
   Insulation reinstall or upgrade. New Johns Manville or equivalent insulation is installed to manufacturer spec, never compressed, never bridging across gaps.
6. 6
   Post-job verification. We run the blower-door again and hand you printed pre- and post-numbers, plus the photo record. The 365-Day Done Right Promise begins when you sign the completion certificate.

Before

After

What Johns Manville Crawl Space Encapsulation & Vapor Barrier Costs in New Braunfels

Homes in the River Road corridor or near Landa Park often need additional perimeter drainage work due to higher water tables, which adds $800-$1,500. We don’t guess at price; we measure and write it down. Call (830) 243-6352 for a free estimate with a written scope.

Why New Braunfels Homeowners Call Topside Attic Insulation New Braunfels for Johns Manville Work

We’ve sealed and insulated over 9,000 homes since 2016, and we treat air sealing as a prerequisite, not an upsell. On every crawl space job, we publish before-and-after blower-door numbers so you can verify the performance change. Our technicians are background-checked, uniformed, and trained on Johns Manville product lines specifically, including the failure modes we’ve documented in local homes. We also service Reflectix and other major brands, so we’re not locked into one manufacturer’s product ecosystem. Calls are answered by a live person 24/7, and we offer a free second opinion on any written estimate you bring us. The Haven Standard means you get a written price before work starts, a documented photo record when we leave, and the 365-Day Done Right Promise if anything isn’t right.

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