Demilec Attic Insulation: The Austin Owner’s Guide
If you have Demilec spray foam or injection foam in your Austin attic and it’s failing, delaminating, or never performed right in the first place, we can fix it. A typical Demilec attic insulation repair or full replacement in Austin runs $2,400 to $6,800 depending on square footage, access, and whether we’re spot-fixing or removing and reinstalling. Most jobs are done in one day. The way most Austin homeowners discover a Demilec problem is the same every time: they climb up to pull down the holiday decorations, notice the foam has shrunk away from the rafters, or they get an August electric bill that makes them want to sit down on the kitchen floor.
The honest truth about Demilec foam is that it’s a good product when it’s installed right. Closed-cell Demilec works as both insulation and an air barrier. But Texas heat puts demands on spray foam that milder climates don’t. Attic temperatures in Austin regularly hit 140°F in July and August, and that sustained heat is where failed Demilec installations start to show themselves: shrinkage around the edges, brittle sections, and in older open-cell jobs, a slow drop in R-value as the foam degrades. We get called to look at these attics constantly, from Tarrytown bungalows to East Austin new builds.
Aspen Attic Insulation is an independent insulation contractor. We’re not affiliated with Demilec, but we stock and install Demilec-compatible materials on our trucks every day, alongside products from Owens Corning, Johns Manville, Knauf, Rockwool, CertainTeed, Icynene, and GreenFiber. If your attic has Demilec foam that needs attention, we’ll tell you straight what’s salvageable and what isn’t, and we’ll put the price in writing before anyone touches your house.
Which Demilec Models This Applies To
Demilec makes several foam lines that show up in Austin attics, and the compatibility question matters because you can’t just slap one foam over another and call it fixed. The two you’ll most likely have are Sealection 500 (open-cell, half-pound, usually 3.5 to 5.5 inches on the attic floor or roofline) and Heatlok HFO (closed-cell, two-pound, typically 2 to 3 inches). There’s also a lesser-seen Airmetic line in some commercial crossover work. The fastest way to identify what’s up there: look for the pale yellow color and soft, sponge-like texture of Sealection versus the denser, rigid, darker yellow-orange of Heatlok. The density is the giveaway. Open-cell you can dent with a finger. Closed-cell you can knock on like a door.
The compatibility gotcha we run into in Austin regularly: you cannot spot-fill open-cell Sealection with closed-cell Heatlok and expect it to work long-term. The two cure differently, they expand at different rates, and the bond between them breaks down faster in a hot attic. Anyone who tells you otherwise is trying to use what’s on their truck instead of what your attic needs. When we repair Demilec, we match the foam family unless we’re doing a full removal, and we’ll explain the OEM versus aftermarket decision in plain language before you spend a dollar. For most Demilec repairs, we use the Demilec-compatible product because the chemistry matches. There’s no savings worth taking in an aftermarket foam that someone else’s warranty won’t honor.
Signs Your Demilec Attic Insulation Is Failing
- Foam pulling away from rafters or sheathing. This is shrinkage, and it’s the most common Demilec failure we see in Austin. When closed-cell foam cures too fast in high heat, it contracts. Gaps of even half an inch become thermal leaks that undo the foam’s air-sealing benefit.
- Rooms over the garage or bonus room running 8 to 12 degrees hotter than the rest of the house. That’s almost always a failed or thin section of Demilec on the roofline above. Heat finds the weak spot and pours through it.
- Visible cracking or crumbling when you touch the foam. Healthy Demilec should feel solid, not like a dry sponge. UV exposure during construction or trapped heat can make open-cell brittle. Crumbling foam is done. It doesn’t recover.
- Musty smell in the attic after rain. Open-cell Demilec can hold moisture if a roof leak develops, and in Austin’s humidity that becomes a mold risk fast. Closed-cell resists water, but open-cell doesn’t. We inspect for this on every call.
- Your AC runs constantly and still can’t hold 78°F. If your Demilec insulation was installed thin, missed sections, or has failed, your HVAC is fighting the attic heat and losing. That’s the signature Austin symptom. Garrett’s been in enough attics near the Domain and in Allandale to know exactly what it looks like.
Replacement Cost & What’s Included
For a typical Austin single-family home, here’s what Demilec attic insulation work costs with us:
- Small spot repair (under 100 sq ft): $400 to $900, same-day in most cases
- Partial attic foam replacement (300 to 700 sq ft): $1,500 to $3,200
- Full attic Demilec removal and reinstall (1,000 to 1,500 sq ft): $4,000 to $6,800
- Attic floor blown-in conversion from failed Demilec: $1,800 to $3,400 depending on depth and coverage
Every quote includes labor, materials, cleanup, and the 365-Day Done Right Promise in writing. That means if the repair fails within a year, we come back and make it right at no charge. The written price you get before work starts is the price you pay. No surprises, no add-ons discovered halfway through pulling the foam out. What drives the range is square footage, ceiling height, access, how much old foam has to be removed, and whether we’re spraying or converting to blown-in. We’ll walk through the numbers with you before you commit.
DIY or Call Us?
Spray foam is not a weekend DIY project. The two-part chemical reaction is exothermic, meaning it generates heat as it cures. Mix it wrong or apply it too thick and you can get a smolder in your attic. That’s not a scare tactic; it’s a documented risk. But there are things a homeowner can safely do before we arrive: check for visible gaps between foam and wood, take cell phone photos of the failed areas, and note which rooms feel hottest in the afternoon. That helps us prepare the right material mix before we show up. The application and repair itself, that’s our job. Spray foam done wrong in a 140°F Austin attic doesn’t just fail; it sometimes needs total removal, which costs more than doing it right the first time. Call us at (325) 246-2929 and we’ll send a tech whose name and photo you’ll have before they knock.
FAQs
Closed-cell Demilec installed correctly should last the life of the home, but in Austin’s sustained heat, installations with poor curing or thin coverage often show problems within 5 to 8 years. Open-cell Sealection has a shorter realistic lifespan in our climate, especially if exposed to any moisture or UV. If your Demilec is more than a decade old and you’re seeing higher bills, it’s worth an inspection. Call (325) 246-2929 and we’ll come look.
Yes, when the damage is limited to defined gaps or small sections. We do spot repairs on Demilec foam in Austin all the time, matching the open-cell or closed-cell chemistry and re-sealing the thermal boundary. If the foam is crumbling across a wide area or showing water damage, replacement is cheaper in the long run than patching. We’ll tell you which one you actually need and give you the price in writing either way.
Most Demilec attic insulation repairs in Austin are finished in one day, including prep, application, and cleanup. Full removal and reinstallation on a large attic can run two days. We’ll give you a straight time estimate before we start, and the tech who shows up is the same person whose name and photo we sent you in advance.
Yes. Our Austin trucks carry Demilec-compatible open-cell and closed-cell foam kits for the most common repair sizes, along with materials from Owens Corning, Johns Manville, Knauf, Rockwool, CertainTeed, Icynene, and GreenFiber, plus Reflectix for radiant barrier work. That means most Demilec repairs can happen on the first visit instead of scheduling a second trip. Call for a free estimate and we’ll confirm what your attic needs before we roll.
Call Aspen Attic Insulation Austin for Demilec Repair
If your Demilec foam is failing and your attic’s working against you, your AC never wins. We’ll send a background-checked, ID-badged technician whose name and photo you get before the visit. You’ll get a written price before any work starts, and everything we do is covered by the 365-Day Done Right Promise. Call (325) 246-2929 for a free estimate, any hour. A live person answers.
Written by Garrett Sloane, Owner, Aspen Attic Insulation Austin at Aspen Attic Insulation Austin, serving Austin and nearby areas.