Demilec Radiant Barrier Installation: The Austin Owner’s Guide
We stock and install radiant barrier compatible with Demilec spray foam systems across Austin, with most installations running $1,400 to $3,200 depending on attic square footage, roofline complexity, and whether the barrier is foil-faced sheathing or a retrofit foil application. Same-day and next-day slots are available most weeks. The way most Austin homeowners discover their radiant barrier has failed is simple: the attic gets hotter than it used to, the upstairs AC runs longer, and the July electric bill lands harder than it did the year before.
Radiant barrier is the reflective layer that sits between your roof deck and the attic space, bouncing radiant heat back out before it ever reaches your insulation. Demilec’s spray foam systems often pair with a foil radiant barrier in Texas attics because our climate demands both: the foam seals and insulates, the foil reflects. When that foil tears, delaminates, or was never installed correctly in the first place, the result is measurable heat gain that your attic insulation has to fight. We fix it properly, and we’ll tell you exactly what it costs before we touch anything.
Which Demilec Models This Applies To
Demilec doesn’t manufacture radiant barrier as a standalone consumer product line the way it does spray foam, so what Austin homeowners typically have is a Demilec open-cell or closed-cell spray foam system with a foil radiant barrier component: either a foil-faced OSB roof sheathing, a foil-over-foam retrofit, or a reinforced foil laminate stapled to the underside of the rafters before or after the Demilec foam went in. Our radiant barrier work pairs with any Demilec foam system, including Heatlok HFO high-lift, Heatlok Soy 200, Sealection 500, and the Agribalance open-cell line.
The compatibility gotcha Austin owners run into is this: if you hired someone years ago to install “foil” without asking what kind, you may have single-layer bubble foil that’s now torn and sagging, or a non-perforated foil that trapped condensation against the roof deck. Not all foil is the same. Perforated radiant barrier is required in many retrofit applications to let moisture escape; non-perforated belongs only behind specific cladding or in vented attic configurations where condensation cannot form against the foil. We check the existing material type, the attic venting setup, and the condition of the Demilec foam before recommending anything. It’s a 20-minute inspection that keeps us from selling you the wrong fix.
As for OEM versus aftermarket for radiant barrier: the OEM question matters less here than it does for a furnace control board. Radiant barrier is a passive material, not an engineered component, so the honest answer is that a quality perforated aluminum foil laminate from a reputable manufacturer performs just as well as anything with a Demilec label on it. The spec that matters is emissivity: 0.05 or lower on the foil surface is the industry standard for meaningful heat reflection. We stock double-sided perforated foil with a woven scrim reinforcement because that’s what survives 110-degree Texas roof decks without falling apart, and we also stock Reflectix for specific cavity and duct applications where a bubble-core insulating foil is actually the right call.
Signs Your Demilec Radiant Barrier Installation Is Failing
- Upstairs rooms run 5 to 10 degrees warmer than downstairs at the same thermostat setting. Heat that radiates through the roof deck is no longer being reflected back, so the attic air temp climbs and the ceiling below absorbs it. Radiant barrier failure doesn’t stop heat entirely, but it makes the insulation layer’s job much harder.
- The attic feels like a sauna an hour after sunrise, not by mid-afternoon. A working radiant barrier keeps the attic noticeably cooler in the morning because the sun’s energy is bounced before it warms the air. If the attic is already brutal at 9 a.m., the reflective surface is gone or compromised.
- You can see torn, sagging, or shiny-side-down foil from the attic hatch. Foil that has delaminated from the roof deck, peeled at the seams, or is hanging in sheets is no longer functioning. Installed foil should be taut, continuous, and installed with the shiny side facing an air space. Shiny side against the roof deck with no gap does almost nothing.
- Dust has coated the foil so heavily it no longer looks reflective. Radiant barrier loses effectiveness when the surface collects dust. An attic floor application in a high-traffic attic loses reflectivity within a year or two. Foil on the rafters stays cleaner longer, which is one reason we prefer rafter installation in Austin.
- Your AC runs constantly from May through September and the electric bill tracks upward every summer. Radiant barrier is not a substitute for insulation, but it reduces the heat load your attic insulation faces. When the barrier fails, that heat load lands on your insulation and your AC system, and the utilities show it.
Replacement Cost & What’s Included
Radiant barrier installation in Austin typically runs $1,400 to $3,200 for a full attic. The range breaks down roughly like this:
- Retrofit foil over existing attic floor insulation: $1,400 to $2,400 for a 1,500 to 2,500 square foot attic, materials and labor included.
- Foil stapled to the underside of rafters (preferred for Austin attics): $1,800 to $3,200 depending on roof pitch, access difficulty, and whether we’re also removing and re-installing the old failed material.
- Foil-faced roof decking on a new roof or new construction: $2,200 to $3,200 for typical Austin single-story homes, varies with roof square footage.
Every quote from us is a written price delivered before any work starts. You’ll know the exact dollar figure, and it won’t change at the door unless the scope changes and you approve it in writing. The price includes removal and disposal of failed or damaged foil, the new barrier material, all fasteners, and labor. Warranty: our 365-Day Done Right Promise covers the installation workmanship for a full year. If the barrier sags, tears, or fails within that year, we come back and fix it at no charge. That’s in writing, on every job.
DIY or Call Us?
Here’s the honest split. Radiant barrier is not a high-tension spring or live electrical panel; it’s not dangerous to handle. A homeowner who is comfortable in an attic can absolutely inspect the existing foil, check for tears and delamination, and measure their rafter spacing. You can also staple up your own foil if you have the time, the right staple gun, and the patience to work in a hot, cramped space.
What goes wrong in DIY radiant barrier work in Austin is usually not safety, it’s effectiveness. Foil installed shiny-side against the deck with no air gap doesn’t work. Foil overlapped incorrectly leaves heat channels. Non-perforated foil in the wrong attic traps moisture and can hide roof deck rot until it’s a major repair. And working in a 130-degree attic during a Texas summer is miserable, slow work that most people abandon halfway through. If you want it done correctly in one afternoon by a crew that does this every week, call us at (361) 321-0817. Chase Whitaker will walk you through what your attic actually needs, and if you’re on the fence, the estimate is free.
Tell me your square footage and I’ll give you a real number, no runaround.
FAQs
A properly installed perforated radiant barrier on the rafters lasts 15 to 25 years in Austin’s climate, while foil laid on the attic floor typically loses meaningful reflectivity within 5 to 10 years because of dust accumulation. The failure we see most often is not the foil itself aging out; it’s poor original installation that sags, tears, or never had the required air gap to start with. Call (361) 321-0817 and we’ll inspect what you have at no charge.
Yes, if the damage is localized, such as a torn section or a few sagging runs, we can patch and re-secure the existing barrier in place for a few hundred dollars. If the foil is heavily dust-coated, delaminating across large areas, or was installed wrong in the first place, replacement is the better value. We’ll show you photos of what we find and give you that recommendation in writing.
Most Austin attics take one day, between four and eight hours depending on the condition of the existing material, rafter spacing, and whether removal of failed foil is required. We arrive at a live, trackable time, not a four-hour window, and you’ll get before-and-after photo proof of the completed work.
Yes. Our crews keep double-sided perforated woven-scrim foil and Reflectix on the truck, so in most cases we can diagnose the problem and complete the installation in the same visit. We are an independent service provider, not affiliated with Demilec, and we match the barrier material to your attic’s specific venting and insulation configuration rather than installing whatever is already loaded on the truck.
If your Demilec spray foam attic in Austin is hotter than it should be, or you know the radiant barrier has failed and you want it replaced correctly and priced honestly, call Laurel Attic Insulation Austin at (361) 321-0817. We answer live, 24/7, and the estimate is free.
Written by Chase Whitaker, Owner, Laurel Attic Insulation Austin at Laurel Attic Insulation Austin, serving Austin and nearby areas.