Demilec Spray Foam Insulation Nationwide

Demilec Spray Foam Insulation in San Marcos: What to Know First

We provide independent Demilec spray foam insulation service in San Marcos, typically completing most jobs same-day or next-day after diagnosis. Most homeowners receive a written price before any work starts, and every job closes with a documented photo record. If your Demilec system needs open-cell touch-up, closed-cell density correction, or full removal and reapplication, we’ll run a blower-door test first so we know exactly what the building envelope is doing before we change it.

Call (737) 337-8049

This page is for San Marcos homeowners who have a Demilec product installed - or are considering one - and need a technician who understands how Demilec’s chemistry behaves in the local climate. Call (737) 337-8049 to schedule a free estimate. A live person answers, 24/7.

How Demilec Products Fail - and How We Fix Them

• Demilec SEALECTION 500 open-cell shrinkage in vented attics. We’ve found this in several San Marcos homes built 2018-2021 near the Blanco River corridor, where summer attic temperatures exceed 140°F and the low-density foam pulls away from rafter edges. The fix isn’t more foam over the gap; we cut back to sound substrate, seal the air boundary with compatible Demilec adhesive, then reapply to the correct pass thickness so the next heat cycle doesn’t repeat the failure.
• Demilec Heatlok XT closed-cell odor retention in garage ceiling applications. When this 2.0-lb density foam is applied too thick in a single lift, the exothermic reaction - the heat released as chemicals cure - can trap amine catalysts inside the matrix. Homeowners notice a fishy or ammonia smell that persists past the normal 72-hour off-gassing window. We remove the affected lift, allow full substrate drying, and reapply in 1-inch passes with forced ventilation between each.
• Demilec Heatlok HFO Ultra poor adhesion to OSB roof decking with high moisture content. San Marcos sees spring humidity spikes ahead of summer dry spells, and OSB sheathing above 19% moisture content won’t bond reliably with HFO-blown formulations. We probe with a pinless moisture meter before application; if readings run high, we run dehumidification or schedule around the weather rather than warranty a delamination.
• Demilec Agribalance open-cell dusting and surface degradation in crawl spaces. This bio-based formulation is popular for its renewable content, but the cell structure is more friable than petroleum-based open-cell. In San Marcos crawl spaces with seasonal groundwater fluctuation, we’ve seen the surface develop a powdery residue where relative humidity cycles above 70%. We encapsulate first with a vapor barrier, then apply, or specify closed-cell if the space can’t be conditioned.
• Demilec SEALECTION AgriFoam improper mixing ratio causing off-spec density. The A-side and B-side must hit the manufacturer’s specified ratio within tight tolerance; drift shows up as either heavy, brittle foam or soft, slow-recovering product that won’t hold its R-value. Our rigs run daily calibration checks with a gravimetric cup test - we weigh the output to verify density - and we log the batch numbers so any warranty claim back to Demilec has traceability.

Our Demilec Spray Foam Insulation Process

1. 1
   Call and schedule. A live person answers at (737) 337-8049, 24/7. We book a diagnostic window and text you when the technician is en route - Haven Standard: Arrive on schedule, you get a named technician.
2. 2
   Blower-door test and visual inspection. We pressurize the house to measure air leakage in CFM50 - cubic feet per minute at 50 Pascals of pressure - then inspect the Demilec installation with thermal imaging to find gaps, shrinkage, or delamination the eye misses.
3. 3
   Written price before any work starts. We specify Demilec OEM material or compatible aftermarket based on what’s actually failing, with the trade-offs explained. No work begins until you have the scope, the price, and the warranty in writing.
4. 4
   Air sealing first, then insulation. We seal top plates, can lights, and penetrations before touching foam. The R-value tells you how slow heat moves through the material - the blower-door number tells you whether any of that matters.
5. 5
   Application or removal per spec. Pass thickness, temperature, and substrate moisture all logged. For removal jobs, we use HEPA-contained extraction, not shop vacs, and dispose per Texas environmental guidelines.
6. 6
   Post-work blower-door test and documentation. We run the pressurization reading again, print the before-and-after on one page, and add it to your photo record. The crew cleans; you keep the documentation.

Before

After

What Demilec Spray Foam Insulation Costs in San Marcos

Most Demilec spray foam insulation jobs in San Marcos fall in these ranges:

What moves the price: accessibility (steep roof pitch, confined crawl space), whether removal and HEPA containment is required, and whether the substrate needs moisture remediation first. We also service Reflectix radiant barrier systems if your project involves hybrid insulation strategy. Call (737) 337-8049 for an exact quote - estimates are free, and we provide a Free Second Opinion on any written estimate you’ve already received.

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

We’ve sealed and insulated over 9,000 homes since 2016, every one with a written price before work started and a documented record when the crew left. Our technicians are background-checked and uniformed; they know the difference between a Demilec SEALECTION batch issue and an installation error, and they won’t guess which. The 365-Day Done Right Promise applies to all completed work - if it’s not done right, we make it right - backed by the written scope and warranty you received before anyone lifted a tool. As an independent Demilec service provider, we’re not locked into any single manufacturer’s product line; we source from Demilec, Owens Corning, Johns Manville, and others based on what the building envelope actually needs. Wes Okafor trained in building science at Dawson Technical Institute and has spent two decades diagnosing why attics fail rather than filling them. In San Marcos, that difference shows up in your blower-door number.

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