Demilec Crawl Space Encapsulation Nationwide

Demilec Crawl Space Encapsulation: The Pflugerville Owner’s Guide

Demilec crawl space encapsulation repair in Pflugerville typically runs $2,800-$5,400 for a full system replacement, and we stock the vapor barrier rolls, seam tape, and closed-cell spray foam components for same-day starts on most jobs. Most homeowners in Pflugerville discover trouble when their crawl space humidity climbs above 60% in summer despite the AC running, or when they spot white efflorescence blooming on block walls - signs the Demilec membrane or seal layer has compromised. We carry Demilec-compatible 12-mil and 20-mil reinforced polyethylene barriers, plus the two-part closed-cell foam kits for rim joist and sill plate sealing, on our trucks through the Stone Hill Town Center corridor and across Pflugerville.

Call (737) 259-8352

Which Demilec Models This Applies To

Demilec’s crawl space line centers on their Heatlok HFO Pro and Heatlok XT series - the closed-cell spray foams used for rim joist air sealing - paired with their AgriThane or specified poly vapor barriers for ground coverage. The critical compatibility gotcha in Pflugerville: Demilec’s early 2010s formulations (pre-HFO blowing agent) bond poorly to damp block, which is common in the Blackhawk and Heatherwilde subdivisions where seasonal clay expansion traps moisture against foundation walls. If your existing foam is yellowing, crumbling, or pulling away from the sill plate, you likely have the older formulation.

To identify your system, check the spray foam canister labels left behind (most installers in Pflugerville don’t remove them) or measure the cured foam density - Heatlok HFO Pro cures to 2.0-2.2 lbs/ft³, visibly firmer than the 1.7-1.9 lbs/ft³ of older open-cell or first-gen closed-cell products. We stock OEM Demilec foam kits and source equivalent 2.0+ lb density closed-cell from Icynene and Johns Manville when the lead time on Demilec’s HFO Pro runs long. For vapor barriers, the 20-mil woven-reinforced spec outlasts the 12-mil in Pflugerville’s alkaline clay soils - we’ve pulled 12-mil barriers at 6 years that looked like Swiss cheese from abrasion, while 20-mil installations in the same neighborhood hit 12+ years.

Signs Your Demilec Crawl Space Encapsulation Is Failing

• Humidity readings above 60% year-round. A properly sealed crawl space in Pflugerville should hold 45-55% relative humidity. If your sensor climbs past 60% even in October, the vapor barrier has likely torn at seams or the rim joist foam has cracked, letting outside air migrate through the envelope.
• Musty odor entering the first floor through gaps in flooring. This means airborne mold spores and soil gases are bypassing the encapsulation layer. In Pflugerville’s clay-heavy soils, hydrostatic pressure can lift barrier edges at the perimeter - a failure mode we see regularly in homes built 2005-2015 with skimpy 6-inch overlap at seams.
• White powder on block walls (efflorescence). That’s mineral salts left by evaporating moisture. It appears when the vapor barrier no longer blocks ground moisture migration, or when the Demilec foam at the sill plate has degraded and no longer forms a capillary break.
• Insect or rodent activity increasing in the crawl space. Gaps in barrier seams or deteriorated foam create highways. We’ve found where mice have chewed through 12-mil poly at fastening points in Pflugerville’s older Shadow Creek builds - the 20-mil woven product with stainless-steel fasteners resists this.
• Floor insulation batts sagging or falling. In encapsulated crawl spaces, the floor should stay dry enough to keep fiberglass in place. Saturated batts mean the encapsulation has failed as a moisture management system, and the Demilec foam or barrier needs inspection.

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Replacement Cost & What’s Included

In Pflugerville, most Demilec crawl space encapsulation replacements we handle fall between $2,800 and $5,400 installed. The spread depends on three factors: crawl space square footage (1,200 sq ft is typical for a single-story in the Windermere or Avalon areas), whether we can salvage the existing barrier or need full removal, and if the rim joist foam requires scraping and reapplication.

Every job opens with a written price - Haven Standard Clause 1 - and closes with a Documented Photo Record showing before-and-after conditions. The 365-Day Done Right Promise covers all encapsulation work. We do not start without the written scope and warranty in your hand.

DIY or Call Us?

There’s safe checking, and then there’s the part where most Pflugerville homeowners call us.

What you can safely do: shine a flashlight on the vapor barrier and look for tears, lifted edges, or standing water. Check your humidity sensor if you have one. Photograph anything suspicious - those photos help us scope the job before we arrive.

Where DIY goes wrong: crawling through a confined space with possible mold exposure, attempting to remove old spray foam with hand tools (the dust is respiratory hazard), or installing new poly without sealing the rim joists first - which is blowing insulation over an unsealed attic floor, just underground. The conditioned crawl space only works when the air sealing precedes the barrier. We’ve been called to redo homeowner wraps in the Rowe Lane area where the barrier went down beautifully but the sill plates still leaked 400 CFM50 of conditioned air.

Topside Attic Insulation Pflugerville is an independent service provider - not affiliated with Demilec - and we stock Demilec-compatible materials plus equivalents from Owens Corning, Johns Manville, and Icynene. Call (737) 259-8352 for a free estimate with written pricing before any work starts.

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