Demilec Spray Foam Insulation in Seguin: What to Know First
We provide independent Demilec spray foam insulation service in Seguin, Texas, with most jobs scheduled within 48 hours and completed in a single day. Our written price - flat, itemized, delivered before any work starts - typically runs $1,800 to $4,200 depending on the Demilec system, cavity depth, and whether we’re addressing existing foam degradation or installing new. Call (830) 549-6646 for a free estimate with no obligation to book.
This page is for homeowners in Seguin and the Hill Country edge who have a Demilec spray foam installation that isn’t performing: hot rooms, high humidity, visible foam shrinkage, or energy bills that climbed despite the “insulated” label. We’ve worked on Demilec products in neighborhoods from Mill Creek Crossing to the older builds near Guadalupe Regional Medical Center, where the combination of hard Texas sun and seasonal humidity creates a specific stress profile on open-cell and closed-cell formulations alike.
How Demilec Products Fail - and How We Fix Them
- Heatlok HFO High Lift shrinkage in vented attics. This closed-cell product is rated for high lift application, but in Seguin’s climate - where attic temperatures exceed 140°F for weeks each summer - we’ve measured 8-15% linear shrinkage in lifts over 3 inches when the substrate wasn’t properly conditioned. The fix isn’t adding more foam; it’s removing the compromised lift, verifying substrate moisture content below 18%, and reapplying in controlled passes. We document substrate readings with a pinned moisture meter before we start.
- Heatlok XT adhesion failure on OSB roof decks. The XT line’s higher density can delaminate from oriented strand board when installed over dusty or slightly damp sheathing, common in Seguin homes built during the 2018-2021 construction rush. We find this as sagging foam at the ridge or gaps at the rafter heels. Our repair involves mechanical removal, vacuuming to bare wood, priming with a water-based acrylic conditioner, then reapplication at reduced pass thickness.
- Sealection 500 open-cell moisture retention in crawl spaces. This 0.5 lb/ft³ open-cell product performs well in walls but traps ground moisture in crawl spaces with poor vapor barrier integration. We’ve pulled saturated Sealection 500 from homes near the Guadalupe River basin where seasonal water tables rose higher than the original assessment indicated. The repair pairs foam removal with full encapsulation - 20-mil reinforced liner on walls and floor - before any reinstallation.
- Demilec AgriThane off-gassing in agricultural conversions. This lower-density agricultural formulation sometimes gets repurposed in residential pole barns or shop conversions around Seguin’s rural fringe. The isocyanate ratio in early-cure AgriThane can produce detectable VOCs for 72+ hours if the A and B components weren’t temperature-matched at the gun. We ventilate, test with a photoionization detector, and reapply only after readings drop below 50 ppb.
- Heatlok Soya HFO surface degradation from UV exposure. Even brief UV exposure - a week of uncovered roof deck work before drywall - degrades the surface skin of this bio-based closed-cell product, creating a chalky layer that won’t accept paint or sealant. We see this in Seguin spec homes where scheduling gaps left foam exposed. Our fix is controlled surface removal to sound foam, then immediate application of a compatible acrylic coating or cover board.
Our Demilec Spray Foam Insulation Process
- 1
Call and scheduling. A live person answers 24/7. We book a site visit, usually within 48 hours. You’ll get a text when the technician is en route.
- 2
On-site assessment and blower-door test. We run a blower-door test - a pressurization diagnostic that measures how much conditioned air your building envelope loses per hour - to establish baseline ACH50. For Demilec repairs, we also probe existing foam with a moisture meter and document density with a core sample where accessible. The report goes home with you - the numbers do the talking.
- 3
Written scope and price. Before any work starts, you receive a flat price, written scope, and written warranty. Haven Standard Clause 1: no surprises, no add-ons without a second signature.
- 4
Substrate preparation and air sealing. We seal top plates, can lights, and penetrations first - always - before any foam touches the surface. For Demilec reapplication, we verify substrate temperature above 60°F and moisture below 18%.
- 5
Demilec application or repair. We match the original product line where appropriate or specify an alternative from our multi-brand inventory - Owens Corning, Johns Manville, Icynene, or Reflectix - if the Demilec formulation isn’t optimal for your specific condition.
- 6
Post-work verification and documentation. We run a second blower-door test, photograph all work, and deliver a printed pre- and post-installation report with ACH50 numbers. The Documented Photo Record and warranty paperwork stay with you.
Before
AfterWhat Demilec Spray Foam Insulation Costs in Seguin
| Job Type | Typical Range | What Moves the Price |
|---|---|---|
| Demilec open-cell wall cavity (standard 2×4, 1,200 sq ft home) | $1,800 - $2,800 | Cavity depth, stud spacing, existing insulation removal |
| Demilec closed-cell roof deck (1,500 sq ft attic footprint) | $3,200 - $4,800 | Lift thickness, deck condition, access difficulty |
| Demilec repair / partial removal and reapplication | $1,400 - $3,600 | Extent of degradation, substrate remediation needed |
| Rim joist spray foam (typical crawl space or basement) | $1,200 - $2,400 | Linear footage, height, existing moisture damage |
| Garage ceiling / conditioned attic conversion | $2,400 - $4,200 | Square footage, fire-rated coating requirements |
These ranges reflect what we’ve written for Seguin-area homes in 2024-2025. Every job gets its own flat price before work starts - no estimate ranges that balloon. Bring us a competing written estimate; we’ll read it with you. Free Second Opinion, no obligation.
Call (830) 549-6646 for your written price.
Why Seguin Homeowners Call Topside Attic Insulation Seguin for Demilec Work
We’re independently owned and operated, not a franchise, and we’ve been working under The Haven Standard since 2016. That means a named technician, a text when they’re en route, and a 365-Day Done Right Promise on every job.
Wes Okafor, our owner and lead technician, learned thermal envelope science at Triton College in River Grove, IL, and has spent over two decades in the trade. His crew has served Seguin and the Hill Country edge for years, including jobs near Guadalupe Regional Medical Center where older attic framing demands air-sealing first, insulation second. We don’t blow foam over unsealed top plates. We don’t guess at performance. We measure it, document it, and hand you the report.
We stock and service multiple brands - Owens Corning, Johns Manville, Knauf, Rockwool, CertainTeed, Icynene, Demilec, GreenFiber, and Reflectix - so our recommendation follows your home’s needs, not a single product line’s sales quota.
FAQs
No - Demilec’s warranty covers product defect, not installation error or environmental degradation, and it remains intact as long as repairs use compatible materials applied to manufacturer specifications. As an independent Demilec service provider, we document our substrate preparation, application conditions, and material batch numbers so any future warranty claim has full traceability. Call (830) 549-6646 if you need help reading your original warranty documents.
We don’t wait on parts. We stock compatible application equipment, replacement guns, and multiple foam formulations from our multi-brand inventory, including Reflectix and Icynene alternatives that perform to the same R-value and permeability specs. For jobs requiring genuine Demilec product, our Seguin location receives next-day freight from Dallas and Houston distribution. Most repairs start within 48 hours of your call.
Repair is cheaper when less than 30% of the foam area shows degradation and the substrate is sound - typically 40-60% less than full removal. Full removal and replacement makes sense when moisture has compromised the substrate, when multiple lifts show delamination, or when the original application density was incorrect for the location. We give you both prices in writing before you decide. Estimates are free.
Three checks: consistent color and texture across the surface (no yellowing, charring, or chalking), no gaps thicker than a quarter inch at framing members, and no odor after 30 days of cure time. We verify with a core density test and moisture probe during our assessment. If your Seguin home was insulated during the 2020-2022 rush, we’ve found a higher incidence of pass-thickness errors and temperature-mismatch issues - worth a look. Call for a free assessment.
We match the product line and approximate lift density where practical, but we don’t promise invisible cosmetic matching - cured foam yellows and oxidizes, and new material will read slightly different. For visible areas, we discuss coating or cover options in the written scope. The performance match is what we guarantee: target R-value, air permeance, and vapor permeance to the original specification. Call (830) 549-6646 for an exact quote - estimates are free.
Written by Wes Okafor, Owner & Lead Insulation Technician, Topside Attic Insulation Seguin at Topside Attic Insulation Seguin, serving Seguin and nearby areas.