Demilec Crawl Space Encapsulation Nationwide

Demilec Crawl Space Encapsulation: The Boerne Owner’s Guide

We stock and install Demilec-compatible crawl space encapsulation systems in Boerne, with most full encapsulations running $3,800-$6,400 depending on crawl square footage and whether the foundation needs active dehumidification tied in. Same-day assessments are available, and we carry Demilec vapor barrier material and seam tape on every truck. Most Boerne homeowners discover their encapsulation is compromised when musty odors return in spring, humidity readings spike above 65% on a basic hygrometer, or their dehumidifier runs continuously without cycling off.

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Which Demilec Models This Applies To

Demilec’s crawl space line centers on their Heatlok HFO and Sealection 500 spray foam systems, plus their poly vapor barrier rolls rated at 10-mil and 16-mil thickness. If your crawl was encapsulated between 2012 and 2020, check the rim joist spray foam for a light green tint - that’s Heatlok HFO, identifiable by its blowing-agent chemistry and slightly firmer cut than open-cell alternatives. Post-2020 jobs more commonly used Sealection 500, which cures to a pale yellow and carries a smoother surface texture.

The critical compatibility gotcha in Boerne’s Hill Country installs: Demilec’s 10-mil barrier was spec’d heavily in 2015-2018, but that thickness struggles against limestone substrate abrasion where crawl floors weren’t pre-graded. We’ve pulled compromised 10-mil sheets in homes near Main Street and the Cibolo Creek watershed where sharp caliche edges wore through in four to six years. For replacement, we match existing mil-rating to maintain warranty continuity, though we typically recommend stepping to 16-mil or adding a protective geotextile pad in high-abrasion zones.

OEM Demilec vapor barrier carries the manufacturer’s material warranty when sourced through authorized distribution. We also install equivalent-grade aftermarket barrier from compatible manufacturers when availability lags, with identical perm ratings and tensile strength - the difference is traceability for any future warranty claim on the original foam work. We document which route we took in your job file, with photos of roll labels.

Signs Your Demilec Crawl Space Encapsulation Is Failing

• Musty odor returning seasonally. When the vapor barrier separates at seams or pulls from foundation walls, ground moisture re-enters the conditioned crawl envelope. In Boerne’s spring humidity spikes, this hits first in homes without dedicated dehumidification - the nose knows before the hygrometer confirms it.
• Visible condensation on ductwork or floor joists. This indicates your dew point is landing on cold surfaces, which means the encapsulation isn’t maintaining the sealed, conditioned environment it was designed for. We see this most in older Boerne homes near the historic district where original pier-and-beam construction creates complex air pathways.
• Spray foam pulling away from rim joists or sagging from overhead application. Demilec’s closed-cell foam can delaminate from damp wood or if applied over untreated fungal growth. The gap becomes a direct air leakage path - stack effect pulls conditioned air out in winter, hot humid air in summer.
• Vapor barrier tearing at seams or punctures from storage/pest activity. Rodent traffic is real in Hill Country crawls. A single breach defeats the barrier’s purpose; moisture migrates through the opening and spreads beneath intact sections, creating trapped condensation you won’t see until mold appears on the underside.
• Dehumidifier running nonstop or failing to reach setpoint. Your dehumidifier is sized for a sealed space. If it’s cycling continuously, the encapsulation has lost integrity somewhere - barrier breach, unsealed vent, or foam failure at the perimeter - and the load has exceeded equipment capacity.

Replacement Cost & What’s Included

What drives the range: crawl square footage is obvious, but the hidden variable is access. A 24-inch clearance with tight corner piers takes longer than a 36-inch walkable space. Limestone substrate requiring grading or geotextile adds material and labor. We measure on-site, then deliver a written price before any work starts - Haven Standard Clause 1, no exceptions.

Every encapsulation job includes seam tape at all overlaps, mechanical fastening at foundation walls, and closed-cell spray foam at penetrations and rim joists as needed. We run a blower-door test when the crawl connects to conditioned space through floor penetrations, and we provide before-and-after readings in writing. The 365-Day Done Right Promise covers all completed work, with your written scope and warranty delivered before anyone lifts a tool.

DIY or Call Us?

Here’s what you can safely check yourself: confirm your dehumidifier is set to 55% relative humidity and draining properly, inspect the vapor barrier for visible tears or pulled seams with a flashlight, and verify foundation vents are sealed if your system was designed as conditioned crawl. These checks cost nothing and tell us plenty when you call.

Where DIY goes wrong: spray foam work requires respiratory protection and ventilation engineering most homeowners don’t have on hand. Cutting away failed foam without identifying why it failed - moisture source, fungal contamination, improper original application - guarantees repeat failure. And laying new vapor barrier in a confined crawl with proper overlap, mechanical fastening, and sealed penetrations is miserable, slow work that looks simple until you’re three hours in with cramping shoulders and a seam that won’t stay flat.

We’ve redone enough homeowner attempts in Boerne to know the pattern. Call (830) 529-7780 and we’ll assess what you’ve got, quote the fix in writing, and get it done without the weekend in a respirator. Seal the envelope first. Then fill it.

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