Demilec Crawl Space Encapsulation & Vapor Barrier Nationwide

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

We provide independent Demilec crawl space encapsulation and vapor barrier service in Morgan Hill, typically completing most jobs in one to two days after diagnosis. Most Demilec crawl space jobs in Morgan Hill run between $2,800 and $6,500 depending on whether we’re addressing a failing Demilec SEALECTION 500 open-cell application or installing a complete encapsulation system with vapor barrier over bare soil. We write the price before any work starts, and you’ll get a documented photo record plus written scope when we leave.

Call (669) 280-8103

This page is for Morgan Hill homeowners who have Demilec spray foam or insulation products in their crawl space and are seeing moisture issues, musty odors, or deteriorating foam. Call (669) 280-8103 to schedule a free estimate with written pricing.

How Demilec Products Fail - and How We Fix Them

• SEALECTION 500 hydrolysis in damp crawl spaces. The open-cell structure absorbs atmospheric moisture when the crawl space isn’t properly encapsulated, causing the foam to darken, shrink, and lose R-value. In Morgan Hill, we see this most often in pre-2018 builds near the Coyote Creek corridor where seasonal groundwater is high. We remove the degraded foam, dry the substrate with targeted ventilation, then install a proper vapor barrier before reapplying closed-cell foam or an alternative system.
• Demilec Heatlok XT delamination from concrete or block walls. This closed-cell product can separate from foundation walls when installed over efflorescence or without adequate surface prep, creating a gap where moisture channels behind the foam. Our fix: mechanical removal, wire-brush surface preparation, application of a masonry-compatible primer, then reinstallation with full adhesion testing.
• Demilec Agribalance in agricultural-adjacent Morgan Hill properties. This bio-based foam performs poorly when exposed to sustained humidity above 70% RH, which is common in crawl spaces without mechanical dehumidification. The foam develops a tacky surface that attracts dust and mold spore loading. We encapsulate with a reinforced polyethylene vapor barrier (typically 12-20 mil) and install a dedicated dehumidifier rather than attempting to salvage the Agribalance layer.
• Vapor retarder misinstallation on Demilec jobs done by non-specialists. We’ve found Demilec foam installed with the vapor retarder facing the wrong direction - toward the conditioned space instead of the ground - which traps soil moisture against the foundation. In one job near Oakwood Avenue, this backward installation had created standing water beneath a supposedly “dry” crawl space. We correct the assembly, install a proper Class I vapor barrier on the soil, and verify with a moisture meter reading at multiple points.
• Demilec HFO Pro closed-cell shrinkage in temperature-variable conditions. Morgan Hill’s warm days and cool nights create thermal cycling that stresses the HFO Pro formulation, particularly at the rim joist where temperature differentials are greatest. Shrinkage gaps at the foam-to-wood interface become air leakage paths. We cut back the compromised foam, seal the joints with compatible sealant, and often supplement with rigid foam board at the rim joist for dimensional stability.

Our Demilec Crawl Space Encapsulation & Vapor Barrier Process

1. 1
   Diagnosis with documentation. We photograph the existing Demilec installation, measure crawl space humidity and temperature at three points, and identify the specific product line and its condition. You get these photos before we propose anything.
2. 2
   Written scope and price. We specify whether we’re removing, encapsulating over, or supplementing the existing Demilec foam. The price is flat; no work starts until you have both in hand.
3. 3
   Moisture remediation first. Standing water gets pumped. We install perimeter drainage if needed. Then we lay a 12-20 mil reinforced polyethylene vapor barrier, seams overlapped 12 inches and sealed with vapor-barrier tape. The soil gets covered completely, including piers and footings.
4. 4
   Air sealing and insulation. Rim joists, sill plates, and penetrations get sealed with appropriate foam or sealant compatible with existing Demilec products. We add insulation - rigid foam, batt, or new spray foam - only after the envelope is sealed.
5. 5
   Verification and record. We run a final moisture check and photograph the completed assembly. If the job included air sealing measurable by blower door, we provide before-and-after CFM50 readings. You walk away with the written warranty, the photo record, and our direct line.

What Demilec Crawl Space Encapsulation & Vapor Barrier Costs in Morgan Hill

What moves the price: crawl space square footage, accessibility (some Morgan Hill hillside homes have 18-inch clearance), extent of existing Demilec degradation, and whether we need to install mechanical dehumidification. We also service Reflectix radiant barrier products if your crawl space has a hybrid system.

Call (669) 280-8103 for a free estimate - we’ll give you the written price before any work starts.

Why Morgan Hill Homeowners Call Topside Attic Insulation Morgan Hill for Demilec Work

We’ve worked on Demilec products in Morgan Hill homes since 2016, from the older ranch-style houses near East Main to newer construction off Condit Road. Wes Okafor, our owner, learned the trade on Chicago’s South Side and at Olive-Harvey College, where blower-door discipline came before insulation installation. That training shows in our crawl space work: we seal the leaks first. The insulation just holds what you’ve already captured.

Our 365-Day Done Right Promise applies to every job. Calls are answered by a live person 24/7. Our technicians are background-checked and uniformed, and they arrive with the written scope already in hand. We don’t upsell vapor barriers to homes that don’t need them, and we don’t install insulation over unsealed air leaks. The photo record and blower-door numbers are included, not extras.

FAQs