Demilec Attic Insulation: The Converse Owner’s Guide
Demilec spray foam insulation installed in Converse attics typically runs $1.80-$3.20 per board foot depending on open-cell versus closed-cell formulation, and most retrofits are completed in a single day. We stock Demilec-compatible material on our trucks and can match existing Demilec installations for patch repairs or full re-insulation jobs. Homeowners usually discover a problem when their summer electric bills spike 30-40% year-over-year, or when they notice the upstairs bedrooms in their Converse home won’t cool below 78 degrees despite the AC running continuously.
Which Demilec Models This Applies To
Demilec operates under the Huntsman Building Solutions umbrella, and the product lines you’ll find in Converse attics are primarily Heatlok HFO Pro (closed-cell, 2.0 lb density), Heatlok XT (closed-cell, higher R-value per inch), and Sealection 500 (open-cell, 0.5 lb density). The label is usually stamped on the foam substrate itself or documented on the original insulation certificate if the prior contractor filed one with Bexar County.
Here’s the compatibility gotcha: Demilec’s closed-cell formulations bond chemically to themselves but not always cleanly to other brands. If you’re patching a section where roofers tore out Demilec during a repair, we need to know whether the existing foam is open-cell or closed-cell. Mixing the two creates a thermal bridge at the joint and can trap moisture. We carry both formulations on our truck, plus a compatible substrate primer for transitions where we’re tying into aged Demilec that’s off-gassed and surface-hardened.
OEM Demilec versus quality aftermarket: for full re-insulation, we source fresh Demilec through our distributor. For repairs under 100 board feet, we sometimes use an equivalent HFO-blown closed-cell from another manufacturer if the thermal performance matches and the chemistry is compatible. We document which material went where in your job folder.
Signs Your Demilec Attic Insulation Is Failing
- Shrinking or pulling away from rafters. Demilec closed-cell can contract 2-5% over the first two years as curing completes. In Converse’s attic heat, accelerated UV exposure through gable vents or missing soffit baffles makes this worse. Gaps at the edges mean conditioned air is leaking past your thermal boundary.
- Discoloration to yellow or brown. Fresh Demilec is cream-colored. Yellowing indicates UV degradation; brown suggests a roof leak or rodent activity above the foam. Either way, the material’s R-value is compromised and may be harboring moisture against the deck.
- Soft or crumbly texture when probed. Properly cured Demilec closed-cell should feel firm, like stale bread. If your attic insulation dents easily or powders under light pressure, the chemical ratio was off during original installation or the substrate was wet when applied. This is common in rush jobs on new Converse construction where framers pushed schedule.
- Uneven temperatures room-to-room below. Demilec spray foam should create a continuous air barrier. If your hallway is 74 degrees and the back bedroom is 82, the foam likely missed a top-plate penetration or the crew sprayed around obstructions without proper thickness.
- Musty odor after rain. Spray foam itself doesn’t mold, but it can encapsulate moisture against wood if applied over a damp substrate. In Converse’s spring storm season, we see this where roof leaks went undetected and the foam trapped water against the sheathing.
Before
AfterReplacement Cost & What’s Included
Most Demilec attic re-insulation jobs in Converse run between $2,400 and $5,800 for a typical 1,800-2,400 square foot home, depending on whether we’re patching sections or stripping and re-spraying. Open-cell runs lower, around $1.80-$2.40 per board foot; closed-cell with HFO blowing agent runs $2.80-$3.20 per board foot. A board foot is one square foot at one inch thickness, and most Converse attics need 5-7 inches of open-cell or 3-4 inches of closed-cell to hit code minimum R-38.
What drives the range: accessibility (steep-pitch attics in older Converse neighborhoods near FM 78 take longer), whether we need to remove failed material first, and how much air sealing is required before we spray. Our price includes the blower-door test before and after, the documented photo record, and the written warranty under our 365-Day Done Right Promise. We don’t start until you have the written price in hand.
DIY or Call Us?
Here’s what you can safely check yourself: verify the Demilec label or certificate if you have it, measure the square footage of your attic floor, and photograph any visible gaps or discoloration. Don’t probe the foam aggressively; degraded spray foam can release isocyanate dust that’s a respiratory irritant.
Here’s where DIY goes wrong: spray foam application requires controlled temperature, humidity, and substrate moisture content. The chemicals are two-part and ratio-critical; off-ratio foam fails to cure properly and emits odors for months. In Converse’s summer attic heat, substrate temperatures above 110 degrees can cause the foam to skin over before it rises, creating voids you won’t see until the thermal camera comes out. We run a moisture meter on every deck and a substrate thermometer before we open the tanks. Call (830) 420-0953 and we’ll give you a written price before any work starts.
FAQs
How long does Demilec attic insulation last in Converse?
Properly installed Demilec closed-cell foam lasts 30+ years, but Converse’s combination of intense attic heat and occasional freeze-thaw cycling means we see degradation accelerate after 15-20 years if the original application was thin or the roof deck wasn’t properly prepped. Open-cell formulations absorb more vapor movement and tend to show wear sooner in our climate. Call (830) 420-0953 for a free assessment of your specific installation.
Can failed Demilec be repaired, or does it all need replacement?
Localized failure can be patched if the surrounding foam is sound and properly adhered. We cut back to solid substrate, prime the transition, and spray new material to match. If the failure is widespread or the original application was under thickness, partial or full replacement is more cost-effective than chasing individual patches. We stock both Demilec and compatible aftermarket material for either scenario.
How long does a Demilec attic insulation job take?
Most residential jobs in Converse are completed in one day: morning prep and air sealing, afternoon spray application, evening re-occupancy after the recommended cure time. Full removal and re-application adds a day. We schedule around your availability and text when the crew is en route.
Do you stock Demilec material, or is there a wait?
We carry Demilec-compatible closed-cell and open-cell formulations on our truck, along with the substrate primers and transition tapes needed for patch work. For full attic jobs requiring larger volume, we pull fresh material from our San Antonio distributor with 24-hour lead time. Same-day starts are available for most repair situations.
Seal the leaks first. Then insulate. The numbers will tell you if it worked.
Ready to fix your Demilec attic insulation? Call (830) 420-0953 for a free estimate with upfront pricing. Every job gets a written scope, documented photos, and before-and-after blower-door numbers so you can see exactly what changed.
Written by Wes Okafor, Owner & Lead Insulation Technician, Topside Attic Insulation Converse at Topside Attic Insulation Converse, serving Converse and nearby areas.