Demilec Crawl Space Encapsulation & Vapor Barrier in Cedar Park: What to Know First
Most Demilec crawl space encapsulation and vapor barrier jobs in Cedar Park run same-day to next-day, with written pricing delivered before any work starts. As an independent Demilec service provider, we service the full Demilec line, including Heatlok HFO Pro, Heatlok XT, and Demilec 500 open-cell systems found in homes across Cedar Park’s newer subdivisions and retrofit projects. Typical vapor barrier replacement with full encapsulation runs $2,800-$5,400 depending on crawl square footage, existing moisture damage, and whether the original Demilec foam has degraded into the poly facing. Call (737) 245-6428 for a free estimate with a written price before any work begins.
This page is for homeowners in Cedar Park, Leander, and Northwest Austin who find their Demilec-insulated crawl space holding humidity, showing foam discoloration, or smelling musty, and want to know whether the original installation can be salvaged or needs full encapsulation replacement.
How Demilec Products Fail - and How We Fix Them
- Heatlok HFO Pro hydrolytic degradation in Cedar Park’s clay soils. The HFO blowing agent in newer Heatlok formulations can trap moisture against crawl block walls when the vapor barrier laps aren’t sealed to grade. We’ve pulled failed HFO Pro in Cedar Park homes near Cypress Creek where seasonal clay expansion pushed groundwater through foundation joints, saturating the foam’s open cells from the back side. We cut back to sound substrate, apply a mechanical fastener base, and reinstall with a full perimeter drainage plane.
- Demilec 500 open-cell overspray onto poly vapor barriers. Open-cell foam doesn’t function as its own vapor barrier, yet we regularly find Demilec 500 sprayed directly onto dirt-floor poly in older Cedar Park builds from the 2012-2016 spray-foam boom. The foam wicks ground moisture, gains weight, and delaminates in sheets. Our fix: remove the contaminated foam mechanically, lay a new 10-mil reinforced poly with sealed seams, then apply closed-cell only where structural adhesion is needed.
- Heatlok XT thermal drift in unvented crawl spaces. XT’s higher density can mask air movement, but it won’t stop it. In Cedar Park’s humid shoulder seasons, we measure crawl spaces with XT that read 72% RH on our psychrometers despite “insulated” walls. The foam is intact; the air sealing isn’t. We supplement with targeted seam sealing and, where the original spec skipped it, a conditioned-air supply tap per ASHRAE 62.2.
- Demilec foam-to-wood contact without ignition barrier. Cedar Park adopted the 2021 IRC amendments requiring thermal/ignition barriers on foam in crawl spaces. Pre-2021 jobs with exposed Demilec foam now fail resale inspections. We document existing conditions with photos, quote the intumescent coating or thermal barrier upgrade, and provide the inspector-signed documentation the homeowner needs to close.
- Reflectix hybrid installations with failed tape seams. Some Cedar Park crews paired Demilec foam with Reflectix radiant barrier on crawl ceilings, then sealed seams with HVAC foil tape that degrades in crawl humidity. We find tape hanging in ribbons and Reflectix acting as a condensing surface. We remove the failed tape system, install proper mechanical fastening, and reseal with acrylic-based tapes rated for below-grade moisture exposure.
Our Demilec Crawl Space Encapsulation & Vapor Barrier Process
- 1
Pre-install infiltration test. We run a blower-door test - a pressurization reading that shows, in one number, how much conditioned air the house is losing - and record ACH50 baseline before touching the crawl space.
- 2
Condition documentation with photos. Every square foot of existing Demilec foam, vapor barrier, and wood condition is photographed. The homeowner receives this Documented Photo Record with the written scope.
- 3
Removal and substrate prep. Contaminated or failed foam is mechanically removed. We specify OEM-compatible replacement foam or, where the original spec was flawed, a corrected material selection from our multi-brand inventory including Demilec, Icynene, and Johns Manville.
- 4
Air sealing before insulation. Seal the leaks first. Then insulate. The order matters more than the product. Top plates, band joists, and penetrations are sealed with appropriate materials before any new foam or barrier goes in.
- 5
Encapsulation with verified seams. New 10-mil or 12-mil reinforced poly is laid, overlapped 12 inches minimum, and sealed with acrylic tape or mechanical fasteners per seam location. Walls are treated per the written scope.
- 6
Post-work verification. We rerun the blower-door test and provide the homeowner with before-and-after ACH50 numbers, plus the written warranty under our 365-Day Done Right Promise.
What Demilec Crawl Space Encapsulation & Vapor Barrier Costs in Cedar Park
| Scenario | Typical Range |
|---|---|
| Vapor barrier replacement only (no foam work), crawl under 1,000 sq ft | $1,800-$2,800 |
| Full encapsulation with new 10-mil poly, seam sealing, wall treatment | $2,800-$4,200 |
| Demilec foam removal + encapsulation + new closed-cell application | $4,200-$5,400 |
| Add ignition/thermal barrier for code compliance | $800-$1,400 additional |
Price movers: crawl height (less than 18 inches adds labor), existing mold remediation needs, and whether the HVAC ducting must be temporarily relocated. We provide a Written Price Before Any Work Starts, always, with no surprise line items. Free Second Opinion on any written estimate from another contractor - bring us their scope and we’ll read it with you. Call (737) 245-6428 for your written estimate.
Why Cedar Park Homeowners Call Topside Attic Insulation Cedar Park for Demilec Work
We’ve sealed and insulated over 9,000 homes since 2016, every one with a written price before work started and a documented record when the crew left. In Cedar Park specifically, Wes Okafor has run jobs from Buttercup Creek to the Ranch at Brushy Creek, and our crews know the difference between Heatlok HFO Pro and Heatlok XT without checking a cheat sheet. We’re not locked to Demilec - we also source from Icynene, Johns Manville, and Owens Corning - so if a different material solves the problem better, we say so. Calls are answered by a live person 24/7. The 365-Day Done Right Promise applies to every job, backed by a written scope and written warranty delivered before anyone lifts a tool.
FAQs
No - Demilec’s limited warranty covers product defect, not installation condition. As an independent Demilec service provider, our encapsulation work doesn’t alter the original product warranty, though we document pre-existing foam condition so there’s no dispute about what failed and when. Call (737) 245-6428 if you need help reading your original warranty paperwork.
Most calls are scheduled within 24-48 hours, and emergency moisture intrusion jobs are same-day when the crawl space is actively wicking water. We answer calls live 24/7, so you’re not waiting through a callback queue while mold propagates. Call (737) 245-6428 to check current availability.
Spot repair is cheaper upfront - typically $800-$1,500 - but only makes sense if the foam is less than 5 years old, fully adhered, and the moisture source is resolved. In Cedar Park’s clay-soil conditions, we find most Demilec foam over 7 years old with any moisture history needs full encapsulation to break the humidity cycle. We’ll show you the photos and give you both prices; the decision is yours.
We stock Demilec-compatible materials and can source OEM foam within 48 hours for color-matched repairs. For encapsulation work, we typically use equivalent or upgraded materials from our multi-brand inventory, including Johns Manville and Icynene, with performance specs that meet or exceed the original. No proprietary lock-in.
You receive a written scope, the written warranty, before-and-after blower-door readings on applicable jobs, and a Documented Photo Record of all work performed. This is Haven Standard practice on every job, no exceptions, so you know exactly what was done and can prove it at resale.
Ready for a written price before any work starts? Call (737) 245-6428 for your free Demilec crawl space encapsulation and vapor barrier estimate in Cedar Park. We’ll run the infiltration test, show you the photos, and give you numbers you can compare.
Written by Wes Okafor, Owner, Topside Attic Insulation Cedar Park at Topside Attic Insulation Cedar Park, serving Cedar Park and nearby areas.