Demilec Crawl Space Encapsulation & Vapor Barrier Nationwide

Demilec Crawl Space Encapsulation & Vapor Barrier in Boerne: What to Know First

Demilec crawl space encapsulation and vapor barrier work in Boerne typically runs $2,800-$6,400 depending on crawl square footage, existing moisture damage, and whether we’re retrofitting over legacy Demilec SEALECTION 500 or installing fresh Demilec Heatlok XT in a conditioned crawl. Most jobs are scoped, priced in writing, and started within 3-5 business days. We are an independent Demilec service provider, not affiliated with or authorized by Demilec, and we work on the open-cell and closed-cell systems already in place across Kendall County.

Call (830) 529-7780

This page is for homeowners who found Demilec foam in their crawl space and need to know whether it’s failing, whether it can stay, and what a proper encapsulation looks like when vapor barrier and drainage are the real problems. Call (830) 529-7780. A live person answers.

How Demilec Products Fail - and How We Fix Them

• Heatlok XT hydrophobic coating breakdown in seasonal flood zones. The gray-pigmented coating on Heatlok XT can chalk and micro-crack after repeated wet-dry cycles in low-lying Boerne areas near Cibolo Creek. We strip the compromised surface layer, verify core density is still above 2.0 lbs/ft³, and install a reinforced 20-mil vapor barrier with sealed seams over a new drainage mat rather than tear out sound foam.
• SEALECTION 500 open-cell water absorption in unvented crawls. SEALECTION 500 is a 0.5 lb/ft³ open-cell foam. When crawl humidity stays above 70% for weeks, it wicks moisture like a sponge, delaminating from joists and dropping R-value from 3.6 per inch toward 1.0. We remove saturated sections, dry the cavity with commercial dehumidification, and replace with closed-cell Heatlok XT or isolate the open-cell behind a conditioned-air envelope.
• Demilec 200 spray adhesive failure on poly vapor barriers. The aerosol adhesive Demilec 200, used to tack 6-mil poly to block walls in quick encapsulations, turns gummy in Boerne’s alkaline soil conditions and loses tack within 18-24 months. We remove the sagging poly, mechanically fasten a woven-reinforced barrier with masonry anchors, and seal penetrations with butyl tape rated for soil contact.
• Heatlok HFO shrinkage at rim joists creating convective loops. Heatlok HFO’s lower global-warming-potential formulation can shrink 3-5% in the first two thermal cycles, pulling away from rim joists in Boerne’s 100°F summer-to-40°F winter swing. We cut back the gap, fill with low-expansion closed-cell touch-up foam, and verify with a smoke pencil that the convective loop is sealed before installing the vapor barrier.
• Demilec foam overspray blocking soffit vents in encapsulated crawls. Crews spraying from below sometimes fill soffit vents with SEALECTION 500 or Heatlok XT, trapping humidity in the crawl cavity. We core out the blocked vents, install baffles to maintain airflow where it’s designed, and document the correction with photos for the homeowner’s record.

Our Demilec Crawl Space Encapsulation & Vapor Barrier Process

1. 1
   Call and schedule. A live person answers 24/7. We book a 90-minute window, send a text when the technician is en route, and arrive with a printed scope template.
2. 2
   Diagnostic walk and moisture mapping. We probe existing Demilec foam with a moisture meter, photograph every elevation, and run a hygrometer log for 48 hours if humidity history is unclear. You’ll see the numbers.
3. 3
   Written price before any work starts. We specify OEM Demilec materials versus quality aftermarket alternatives, line-item each phase, and leave the written scope with you. No work starts without your signature and our price on paper. Haven Standard Clause 1.
4. 4
   Prep, removal where needed, and installation. We HEPA-vacuum the crawl, remove failed foam or barrier sections, install drainage matting, seam-seal the vapor barrier with 4-inch waterproof tape, and integrate with existing Demilec foam where it’s sound.
5. 5
   Testing and documentation. Where applicable, we run a blower-door test - a pressurization reading that shows, in one number, how much air your building envelope is losing - before and after. You get the printed pressure-differential report in pascals, a Documented Photo Record of the completed work, and the written warranty.
6. 6
   365-Day Done Right Promise. If it’s not done right, we make it right. The promise is in writing before anyone lifts a tool.

What Demilec Crawl Space Encapsulation & Vapor Barrier Costs in Boerne

Most Demilec crawl space encapsulation and vapor barrier jobs in Boerne fall into these ranges based on what we find:

What moves the price: crawl height (less than 18 inches adds labor), active water intrusion requiring sump or French drain, asbestos-containing old wrap that must be abated, and whether the HVAC ductwork is in the crawl and needs protection during work. We also service Reflectix radiant barrier systems when they’re part of the same envelope.

Call (830) 529-7780 for an exact quote. Estimates are free, and we offer a Free Second Opinion on any written estimate you’ve already received. Bring us a competing quote and we’ll read it with you.

Why Boerne Homeowners Call Topside Attic Insulation Boerne for Demilec Work

We’ve sealed and insulated 9,000+ homes since 2016, every one with a written price before work started and a documented record when the crew left. In Boerne specifically, we’ve worked the older homes near the Cibolo Nature Center where stack-effect air leakage was eating through cooling bills before a single batt ever went in. Wes Okafor learned the trade at Olive-Harvey College’s building technology program and has been running blower-door tests for going on eighteen years. Our crews know the difference between Heatlok XT and SEALECTION 500 failure patterns without reading a label. We don’t sell proprietary systems, we don’t do urgency theater, and we don’t ask you to trust us. We hand you the numbers in pascals and the photos in a folder. Seal the envelope first. Then fill it.

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