Demilec Blown-In Insulation Nationwide

Demilec Blown-In Insulation in San Marcos: What to Know First

We provide independent Demilec blown-in insulation service in San Marcos, typically completing attic top-ups and dense-pack wall jobs within one business day of your call. Most Demilec cellulose and fiberglass blown-in jobs in a home this size run between $1,800 and $3,400, with a written price delivered before any work starts. This page is for homeowners who already have Demilec insulation in their attics or walls and need to add to it, replace it, or figure out why it isn’t performing the way the label suggested it would. Call (737) 337-8049 for a free estimate or a free second opinion on any written quote you’ve already received.

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How Demilec Products Fail - and How We Fix Them

• Demilec Sealection 500 open-cell spray foam shrinkage at the top plate. In San Marcos homes built during the 2015-2020 boom, we regularly find this foam pulling away from the top plate - the horizontal framing member where your walls meet your ceiling - leaving a gap that lets conditioned air bleed straight into the attic. The R-value tells you how slow heat moves through the material - the blower-door number tells you whether any of that matters. We remove the failed section, seal the gap with compatible acrylic latex sealant, then blow Demilec cellulose over the repair so the thermal layer stays continuous.
• Demilec Heatlok HFO High Lift settling in 2×6 cathedral ceilings. This closed-cell product is specified at full lift height, but in hot San Marcos attics we’ve measured 15-20% shrinkage within three years when the substrate wasn’t properly conditioned during install. The fix isn’t more foam - it’s dense-packing Demilec cellulose into the cavity after stabilizing the remaining foam, which restores the design R-value without trapping moisture against the roof deck.
• Demilec EcoCellulose bridging over irregular joist bays. Blown cellulose needs a flat plane to achieve uniform density; in the older slab-on-grade homes near the Texas State University corridor, we find joists spaced at odd intervals or sistered repairs that create pockets. The cellulose bridges across the high points, leaving voids underneath. We install mesh baffles to contain the fill, then blow to a calculated density of 3.5 pounds per cubic foot so every bay is full.
• Demilec Polarfoam 7300 off-ratio application causing odor recurrence. When the A-side and B-side don’t mix correctly, you get a persistent amine odor that homeowners mistake for a dead animal in the attic. We don’t cover it with more insulation - we cut out the affected areas, verify the substrate is dry, then switch to blown-in fiberglass for that zone since it carries no VOC risk and won’t interact with the residual chemistry.
• Demilec Agribalance moisture absorption in vented attics. This soy-based open-cell foam is hydrophilic - it attracts water - and in San Marcos where humidity spikes before spring storms, we’ve found it saturated in homes with bathroom fans vented into attic space rather than through the roof. We replace the venting route, remove compromised foam, treat the sheathing with borate solution, then blow Demilec fiberglass to avoid repeating the moisture trap.

Our Demilec Blown-In Insulation Process

1. 1
   Call intake with a live person. We ask what Demilec product you have, when it was installed, and what you’re experiencing - hot rooms, high bills, odor, visible settling. We schedule a site visit with a named technician and text you when they’re en route.
2. 2
   Blower-door test and attic inspection. We pressurize the house to measure air leakage in CFM50 - cubic feet per minute at 50 Pascals of pressure - then photograph every condition we find: top plate gaps, can light penetrations, compromised Demilec foam, moisture staining.
3. 3
   Written scope and price. Before any work starts, you get a single page with the blower-door number, our target for improvement, the exact materials we’ll use, and the flat price. This is Haven Standard Clause 1 - no exceptions.
4. 4
   Air sealing first, then insulation. We seal every penetration with fire-rated caulk and foam, repair or remove failed Demilec product as specified, then blow to the density and depth calculated for your assembly. For Demilec cellulose, we verify weight per bag against coverage charts; for fiberglass, we check settled depth against the manufacturer’s coverage statement.
5. 5
   Post-work blower-door test and documentation. We run the pressurization test again, print the before-and-after numbers on one page, and add the photos to your Documented Photo Record. You hold the evidence before we pack the hoses.
6. 6
   365-Day Done Right Promise activation. Your written warranty and scope go in a folder with the blower-door results. If the numbers don’t hold or you find a void we missed, we return and make it right.

Before

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What Demilec Blown-In Insulation Costs in San Marcos

These are real San Marcos numbers based on jobs we’ve completed in neighborhoods from Willow Creek to the historic district near the courthouse. Every estimate is free, and we provide a free second opinion on any written estimate from another contractor - bring us their scope and we’ll read it with you. Call (737) 337-8049 to schedule.

Why San Marcos Homeowners Call Topside Attic Insulation San Marcos for Demilec Work

We’re an independent Demilec service provider - not affiliated with or authorized by Demilec - which means we work across product lines without pressure to sell one manufacturer’s solution. When Demilec foam has failed, we can switch to Johns Manville, Knauf, or Reflectix if the assembly calls for it. Our technicians are background-checked and uniformed; Wes Okafor trains every crew member on blower-door protocol at the shop before they enter a customer’s home. Since 2016, we’ve sealed and insulated over 9,000 homes, every one with a written price first and a documented record at the end. The 365-Day Done Right Promise isn’t a feeling - it’s a clause in the paperwork you sign, with a phone number that rings to a live person, 24/7.

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