Demilec Attic Insulation Nationwide

Demilec Attic Insulation: The Schertz Owner’s Guide

We stock and install Demilec-compatible spray foam and open-cell attic insulation systems for Schertz homes, with most retrofits running between $2,800 and $5,400 depending on attic square footage and whether we need to remove degraded material first. Same-day assessment is available, and we carry Demilec-equivalent formulations on our trucks for homes in the Schertz corridor, including the Sedona subdivision off FM 1518 where we’ve done a fair amount of work. Most homeowners realize their Demilec insulation is failing when they notice uneven room temperatures, rising summer electric bills despite the same thermostat setting, or visible shrinkage and pulling away from rafter bays in the attic.

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Which Demilec Models This Applies To

Demilec produces several formulations under the Heatlok and Sealection brands that were installed in Schertz-area homes between roughly 2010 and 2020, before the company’s product lines shifted. The most common we encounter is Heatlok HFO High Lift, an open-cell spray foam rated at R-3.7 per inch, typically applied to 5.5 inches in rafter bays for a total R-20 assembly. You can identify your installed product by locating the Demilec lot label, usually spray-painted or stickered onto a rafter near the attic access hatch; it will show the product series, install date, and certified applicator’s ID number.

The OEM-versus-aftermarket question for Demilec is straightforward: we do not source proprietary Demilec-branded material because Demilec sells through a certified-applicator network that restricts product to trained installers. What we stock are equivalent open-cell formulations from Icynene and Johns Manville that match the density (0.5 lb/ft³), permeance (typically 10-15 perms), and expansion characteristics of your original Demilec application. For Schertz homes with Heatlok installed, the critical compatibility check is lift thickness - HFO High Lift was designed for passes up to 5.5 inches without delamination; substituting a standard-lift foam requires additional passes and changes the installed cost structure.

Topside Attic Insulation Schertz is an independent service provider with no affiliation to Demilec. We also stock parts and materials for Reflectix radiant barrier systems.

Signs Your Demilec Attic Insulation Is Failing

• Uneven ceiling temperatures and hot rooms. When Demilec open-cell foam shrinks or pulls away from rafter edges, thermal bridging occurs at the gaps. We see this most often in Schertz homes where attic ventilation was added after the foam was installed, creating temperature swings that stress the foam-to-wood bond.
• Visible shrinkage or yellowing in the attic. Demilec’s open-cell formulations can oxidize and discolor to a deep yellow or amber over 8-12 years in Texas attic conditions. The color change itself is cosmetic, but accompanying dimensional shrinkage of 10-15% indicates the foam is no longer filling its cavity and air is moving behind it.
• Spiking summer cooling costs with no equipment change. A blower-door test we ran last year on a Schertz home off Huber Road showed 3,800 CFM50 with the original Demilec still in place; after removal and reinstallation with proper air sealing, the reading dropped to 2,100. The homeowner’s July bill had climbed $140 over three years before they called us.
• Musty odors or moisture staining on ceiling drywall. Open-cell foam is vapor-permeable by design, but when it separates from the substrate, humid Schertz air can condense on the cooler drywall surface behind the gap. This is not the foam failing to breathe - it’s the foam failing to stay attached.
• Pest intrusion in the attic. Gaps at the perimeter of degraded foam create pathways for rodents and insects. We find this particularly in older Schertz subdivisions where mature tree canopies provide roof access; the Demilec itself doesn’t attract pests, but the voids it leaves behind do.

Replacement Cost & What’s Included

Most Demilec attic insulation replacements in Schertz run between $2,800 and $5,400 for a complete removal and reinstall, with the lower end covering 800-1,000 square feet of attic deck and the upper end reflecting larger homes or rafter-bay applications requiring scaffold work. The range is driven by three factors: whether we can foam over the existing degraded material (rarely advisable), the depth of removal required, and whether your home needs complementary air sealing at top plates and penetrations before new insulation goes in.

Our price includes removal and responsible disposal of the old Demilec material, installation of equivalent open-cell foam at specified thickness, and a post-install blower-door test on every job to verify the assembly is performing. Under our Haven Standard, you receive a written price before any work starts, a Documented Photo Record of the completed installation, and the 365-Day Done Right Promise. We do not charge separately for the blower-door test; it is part of verifying that we sealed the leaks first, then insulated.

DIY or Call Us?

There is no safe DIY path for spray foam insulation removal or reinstallation. The Demilec material itself is not hazardous once cured, but removal disturbs fiberglass, possible rodent waste, and decades of accumulated dust; proper PPE and negative-air containment are non-negotiable. Reinstallation requires a plural-component spray rig, heated hose lines, and real-time monitoring of substrate temperature and humidity - conditions that change hourly in a Schertz attic during summer months.

What you can safely check: verify your attic access is secure, note any visible discoloration or gaps in the foam, and photograph the Demilec label if you can locate it. Then call us at (830) 402-5240. We’ll read your situation without pressure, and if you have a competing written estimate, our Free Second Opinion applies. Seal the leaks first. Then insulate. The attic doesn’t care how thick the insulation is if the air is still moving through it.

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