Johns Manville Crawl Space Encapsulation & Vapor Barrier Nationwide

Johns Manville Crawl Space Encapsulation & Vapor Barrier in Cedar Park: What to Know First

We provide independent Johns Manville crawl space encapsulation and vapor barrier service in Cedar Park, with most jobs completed in one to two days and written pricing delivered before any work starts. As an independent Johns Manville service provider, we’re not affiliated with or authorized by the manufacturer, which means we source parts based on what actually solves the problem, not what protects a dealer agreement. Most Cedar Park crawl spaces we see run between 68% and 85% relative humidity year-round, and that moisture load is what kills Johns Manville vapor barriers prematurely if the encapsulation isn’t done as a system. Call (737) 245-6428 for a free estimate with a written scope and price.

Call (737) 245-6428

This page is for homeowners who’ve found Johns Manville insulation or vapor barrier products in their crawl space, or who’ve been quoted a Johns Manville system and want a second opinion on whether it’s the right fit for their house.

How Johns Manville Products Fail - and How We Fix Them

• JM Formaldehyde-free fiberglass batts in vented crawl spaces - The Kraft-faced batts, especially the R-19 and R-30 ranges common in 2015-2020 Cedar Park builds, sag and detach when relative humidity stays above 70% for more than 30 consecutive days. We’ve pulled down batts in the Ranch at Brushy Creek that were hanging by a thread because the facing adhesive failed. We remove the failed batts, air-seal the rim joist and sill plate with closed-cell spray foam, then install a proper encapsulation system so new insulation stays put.
• JM Linacoustic RC (rigid fiberglass duct liner) in damp crawl spaces - This product absorbs airborne sound well but also absorbs liquid water if the crawl space has bulk moisture intrusion. Once saturated, it compresses and loses its thermal value. In Cedar Park’s clay-heavy soils, we see this where downspouts dump against the foundation. We replace saturated Linacoustic with closed-cell spray foam on ductwork, then solve the water source with grading or a sump pump before sealing the envelope.
• JM Spider custom spray fiberglass in encapsulated crawl spaces with incomplete vapor barriers - The loose-fill application bonds to itself, but if the 6-mil poly vapor barrier has gaps at seams or pier wraps, moisture migrates through and condenses on the cool floor joists above. Spider doesn’t wick moisture like cellulose, but it will support mold growth on its surface. We strip the compromised barrier, treat any fungal growth, and install a 12-mil reinforced polyethylene with sealed seams and mechanical fastening at piers.
• JM ComfortTherm encapsulated crawl spaces with no dehumidification - The plastic-wrapped batts resist moisture better than Kraft-faced, but “resist” doesn’t mean “prevent” in a sealed crawl space where humidity can spike to 90% before the dehumidifier catches up. We’ve found ComfortTherm batts in Cedar Park’s New Hope area that were dry to the touch but reading 22% wood moisture content in the joists around them. We always spec a dedicated dehumidifier with our encapsulations, sized to the crawl space volume, not just the square footage.
• JM AP Foil-faced polyiso board at crawl space perimeter walls - The foil facing is an excellent vapor barrier when intact, but fastening through it with standard washers creates hundreds of puncture points. In Cedar Park’s expansive clay soils, foundation movement works those fasteners loose over two to three years. We see lifted boards in the Buttercup Creek subdivision where the gaps let unconditioned air behind the insulation. We switch to mechanical fastening with cap nails on a grid pattern, seal all penetrations with foil tape, and add a protective scuff board at the base where maintenance traffic occurs.

Our Johns Manville Crawl Space Encapsulation & Vapor Barrier Process

1. 1
   Pre-install infiltration test - We run a blower-door test on the living space to measure how much conditioned air the house is losing through the crawl space interface. This gives us a baseline CFM50 reading and tells us whether the crawl space is actively communicating with the house.
2. 2
   Condition assessment with documented photo record - We photograph every pier, every joist bay, every existing Johns Manville product, and any moisture staining or pest damage. You get these photos in your written scope.
3. 3
   Parts decision: OEM Johns Manville versus quality aftermarket - If your existing Johns Manville vapor barrier or insulation can be matched for a proper repair, we source it. If the product line is discontinued or a different material solves the problem better, we tell you why and show you both options with prices. We also service Reflectix products if that’s what your crawl space currently uses.
4. 4
   Air sealing first, then insulation - Seal the leaks first. Then insulate. The order matters more than the product. We seal rim joists, sill plates, plumbing and electrical penetrations, and duct boot connections with appropriate materials before any new insulation goes in.
5. 5
   Encapsulation with reinforced vapor barrier - We install 12-mil reinforced polyethylene across the ground, up piers, and sealed to foundation walls. Seams are overlapped 12 inches and sealed with double-sided tape. The barrier is mechanically fastened at all vertical transitions.
6. 6
   Post-install test and documentation - We re-run the blower-door test and provide you with before-and-after readings, plus the documented photo record of completed work. Every job closes with a written warranty under our 365-Day Done Right Promise.

What Johns Manville Crawl Space Encapsulation & Vapor Barrier Costs in Cedar Park

Most crawl space encapsulation jobs in Cedar Park run between $4,200 and $8,500 for homes between 1,800 and 3,200 square feet. The variables that move the price are:

• Existing Johns Manville removal required: $800-$1,800 additional if batts or board insulation must be stripped and disposed of
• Active moisture remediation: $1,200-$2,800 for sump pump installation, French drain, or grading correction
• Dehumidifier sizing and installation: $1,100-$1,900 for a 70-pint to 90-pint unit with condensate pump
• Rim joist spray foam: $900-$1,600 for closed-cell application at the perimeter
• Wood moisture treatment: $600-$1,400 if fungal growth requires remediation before encapsulation

We don’t quote by square footage alone because a 2,400-square-foot house on a wet lot in Cedar Park’s Brushy Creek North can need twice the moisture control of the same footprint on higher ground near Cypress Creek. We give you a flat written price before any work starts, always. Bring us any competing written estimate and we’ll do a free second opinion, line by line.

Why Cedar Park Homeowners Call Topside Attic Insulation Cedar Park for Johns Manville Work

We’ve been running jobs in Cedar Park since 2016, and Wes Okafor has spent several years in the field here, including retrofits in Buttercup Creek where attics hit 140°F and crawl spaces stay wet year-round. We don’t sell encapsulation as a cosmetic upgrade. We measure the air leakage, fix it, then insulate, and we hand you the blower-door numbers that prove the difference.

Our materials come from Johns Manville, Owens Corning, Knauf, Rockwool, and other manufacturers, so we’re not locked into pushing one product line. If your crawl space needs something Johns Manville doesn’t make, we’ll tell you. Every crew is background-checked and uniformed, and a live person answers calls 24/7. The 365-Day Done Right Promise means if it’s not right, we make it right, with the written warranty delivered before anyone starts.

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