Demilec Crawl Space Encapsulation & Vapor Barrier in Schertz: What to Know First
We provide independent Demilec crawl space encapsulation and vapor barrier service in Schertz, typically scheduling within 48 hours and completing most jobs in a single day. Most crawl space encapsulation jobs we handle in Schertz run between $2,800 and $5,500 depending on square footage, existing moisture damage, and whether the Demilec foam needs remediation before the new barrier goes down. This page is for homeowners who’ve found Demilec spray foam in their crawl space and need to know whether it can stay, what it’s doing to the air below their floor, and what fixing it actually costs. Call (830) 402-5240 for a free estimate with a written price before any work starts.
How Demilec Products Fail - and How We Fix Them
- Demilec Heatlok HFO Pro series shrinkage at rim joists. The HFO blowing agent can contract 8-12% over the first two Texas summers, pulling away from sill plates in Schertz’s clay-heavy soil zone where seasonal expansion cracks the bond. We cut back the failed sections, treat the wood with a mold-preventative borate solution, and reinstall with a hybrid closed-cell application that accounts for substrate movement.
- Demilec Sealection 500 water absorption in flood-prone crawl spaces. Open-cell foam near the Schertz aquifer zone wicks moisture like a sponge when the Guadalupe River basin runs high; we’ve pulled saturated Sealection 500 that gained 40% weight and dropped to R-3 per inch. We remove the waterlogged foam, install a proper 20-mil vapor barrier with sealed seams, then replace with closed-cell only below the 18-inch flood line.
- Demilec Heatlok XT off-gassing in encapsulated, unvented crawl spaces. When homeowners seal their crawl space without addressing the XT’s amine catalyst residuals, you get a chemical “attic smell” that migrates through floor penetrations. We ventilate and test with a photoionization detector before encapsulating, then specify a zero-VOC barrier membrane if readings exceed 500 ppb.
- Demilec open-cell foam rodent nesting in unsealed crawl spaces. Demilec’s open-cell products, particularly older Agribalance formulations, provide ideal burrowing substrate for roof rats common in Schertz’s established neighborhoods near Pickrell Park. We remove contaminated foam, install galvanized hardware cloth at all penetrations, then encapsulate with a rodent-resistant reinforced polyethylene barrier.
- Demilec Heatlok HFO High Lift delamination from OSB subflooring. The high-lift chemistry can exotherm too aggressively on hot Schertz install days, creating a weak boundary layer that separates when the crawl space humidity cycles. We grind to bare wood, apply a moisture-cured urethane primer, and reinstall in two controlled lifts with a 24-hour cure between passes.
Our Demilec Crawl Space Encapsulation & Vapor Barrier Process
- 1
Pre-work inspection and moisture mapping. We pull relative humidity readings at six points, identify the Demilec product line and install date if possible, and photograph every condition before touching anything.
- 2
Blower-door and crawl space pressure testing. We run a blower-door test - a pressurization reading that shows, in one number, how much air your building envelope is losing - then measure the pressure differential between house and crawl space to see if the Demilec foam is actually doing any air-sealing work.
- 3
Remediation scope and written price. Under Haven Standard Clause 1, you get a flat price, written scope, and written warranty before anyone lifts a tool. If Demilec foam stays, we document why; if it goes, we specify disposal per Texas environmental guidelines.
- 4
Air sealing before encapsulation. Seal the leaks first. Then insulate. The attic doesn’t care how thick the insulation is if the air is still moving through it - and the crawl space is no different. We seal rim joists, sill plates, and penetrations with appropriate materials, not whatever’s left on the truck.
- 5
Vapor barrier installation and mechanical dehumidification. We lay 20-mil reinforced polyethylene with sealed seams and mechanical fastening at walls, then size and install a permanent dehumidifier with a condensate pump to the exterior.
- 6
Post-work documentation. You receive a Documented Photo Record, updated blower-door numbers showing the actual air leakage reduction, and a printed thermal-imaging summary. The 365-Day Done Right Promise begins when we leave, not when we collect.
What Demilec Crawl Space Encapsulation & Vapor Barrier Costs in Schertz
Most crawl space encapsulation jobs in Schertz run between $2,800 and $5,500. Here’s what moves the needle:
- Demilec foam remediation adds $800-$2,200. Removing existing foam, treating substrate, and disposing per Texas regulations takes a full day and requires specialized equipment.
- Subfloor repair from moisture damage: $400-$1,800. Common in older Schertz homes near Cibolo Creek where seasonal flooding wets the joist bays before anyone notices.
- Mechanical dehumidifier with condensate pump: $1,200-$1,900 installed. Essential in our humidity zone; without it, you’re collecting water in a plastic bag.
- Standard 20-mil vapor barrier, no remediation: $2,800-$3,800. Clean crawl space, straightforward perimeter seal, no surprises.
We also service Reflectix radiant barrier products if your envelope strategy includes both crawl space and attic work. Call (830) 402-5240 for an exact quote - estimates are free, and the price we write is the price you pay.
Why Schertz Homeowners Call Topside Attic Insulation Schertz for Demilec Work
We’ve been working the Schertz corridor for several years now, including jobs in the Sedona subdivision off FM 1518 where summer attic temps regularly push past 140°F before a single batt goes in. That same thermal reality exists in your crawl space, just inverted - the ground stays warm, the humidity stays high, and the Demilec foam you inherited may be part of the problem, not the solution.
As an independent Demilec service provider, we have no manufacturer obligation to preserve product that isn’t performing. Our techs carry OEM and quality aftermarket options, and Wes Okafor reviews every scope personally before it goes out. The 365-Day Done Right Promise applies to all completed work, backed by a written warranty you hold in your hand before the crew starts. Calls are answered by a live person 24/7 - no voicemail loops, no callback windows measured in business days.
FAQs
No - Demilec’s limited warranty covers product defect, not installation context, so encapsulation itself doesn’t void coverage. However, if the foam was installed by a Demilec-authorized contractor, altering the ventilation strategy the original installer specified could complicate any claim you later file. We document pre-existing conditions with photos and moisture readings so there’s a clear baseline. Call (830) 402-5240 and we’ll review your install paperwork with you.
We use quality aftermarket materials for encapsulation and vapor barrier work because Demilec doesn’t manufacture vapor barriers or dehumidifiers - they produce spray foam, and the encapsulation components are always third-party. For foam remediation where new closed-cell is needed, we can source Demilec product or specify equivalent-performing alternatives from Icynene or Johns Manville depending on your preference and the application. We never lock you into a proprietary product.
Repair is cheaper upfront - typically $800-$1,500 versus $3,500-$5,500 for full remediation plus encapsulation - but repair only works if the foam is dry, well-adhered, and the original application was correct. In Schertz’s climate, we find that water-compromised Demilec foam continues degrading even after surface drying, so repair often becomes a second, larger bill within two years. We photograph and test before recommending either path. Call (830) 402-5240 for a free assessment.
Most jobs are scheduled within 48 hours of your call, and we complete single-day encapsulations regularly. Demilec foam remediation adds a day for cure times and disposal logistics. We don’t schedule Friday installs if the Thursday pre-work inspection turns up something the crew needs to address properly - that’s how we avoid the callback. Call (830) 402-5240 to check this week’s availability.
You receive a Documented Photo Record of all work areas, before-and-after blower-door readings on applicable jobs, a printed thermal-imaging summary, and a written warranty under the 365-Day Done Right Promise. Every job begins with a written price and ends with a documented record - Haven Standard, no exceptions.
Written by Wes Okafor, Owner, Topside Attic Insulation Schertz at Topside Attic Insulation Schertz, serving Schertz and nearby areas.