Demilec Radiant Barrier Installation: The Houston Owner’s Guide
We install Demilec-compatible radiant barriers throughout the Houston metro, and most attic jobs run between $0.90 and $1.60 per square foot installed, depending on attic accessibility, existing insulation condition, and whether we’re stapling to rafters or laying over existing insulation. Same-day and next-day installation is available, and our crews carry the materials on the truck. Most Houston homeowners discover a problem with their radiant barrier when their August electric bill hits triple digits and the upstairs rooms won’t hold a temperature below 80, even with the AC running full tilt.
Radiant barrier is a reflective foil material, usually aluminum, installed in your attic to reflect radiant heat away from your living space. In Houston’s climate, where attic temperatures routinely climb past 140°F in summer, a properly installed radiant barrier can cut heat gain through the ceiling by up to 40%. When it fails, you feel it in every room under that attic.
Woolsey Insulation Houston is an independent insulation contractor. We’re not affiliated with Demilec, but we work with their product line alongside seven other brands, and we know how Demilec’s radiant barrier specs translate to real Houston attics.
Which Demilec Models This Applies To
Demilec’s radiant barrier products fall under a few recognizable names in the insulation trade. The most common in Houston homes are Demilec’s reflective foil insulation products, typically sold as single-sided or double-sided foil, perforated or non-perforated. Perforation matters more than most people think. In a Houston attic with any kind of moisture movement, a non-perforated barrier installed over existing insulation can trap humidity between the foil and the insulation below it, which leads to mold and compressed, ineffective insulation. We see this most often in older ranch-style homes in Meyerland and Spring Branch where original blown-in fiberglass has been covered with foil without checking the attic’s ventilation first.
Identifying what you have is straightforward. Look for a printed label on the foil surface, usually near a seam or along the roll edge. Demilec products carry their brand name and a product code. If the label is gone or unreadable, measure the foil. Most Demilec residential radiant barriers are 48 inches or 60 inches wide. The key compatibility question is whether the foil is perforated or solid, and whether it’s single or double-sided. Mixing a double-sided barrier where a single-sided product was installed originally is fine. Mixing perforated and non-perforated across the same attic is where problems start.
On the OEM versus aftermarket question: for radiant barrier specifically, we don’t get hung up on brand matching. This isn’t like a spray foam rig where the chemical formulation matters for expansion and R-value. Radiant barrier foil is a commodity product. A quality aftermarket foil with the right perforation pattern and a clean aluminum surface will perform just as well as the Demilec-branded roll. We’ll tell you that straight. Where we do insist on quality is in the installation: the foil has to be cut clean, stapled flat without wrinkles, and flashed properly at the eaves to avoid blocking soffit ventilation.
Signs Your Demilec Radiant Barrier Installation Is Failing
- Upstairs rooms run 10°F or more hotter than downstairs. Heat is moving straight through the attic floor because the barrier has torn, sagged, or the foil surface has lost its reflectivity. Reflective foil only works when the surface is clean and shiny. Dust accumulation over years cuts its reflective performance dramatically.
- You can see rips, droops, or missing sections from the attic hatch. Radiant barrier stapled to rafters sags when staples pull out of aged or soft roof decking. Laid-over-insulation foil tears when tradespeople crawl through the attic for AC or wiring work, and foam board radiant barriers crumble at the edges if they get wet.
- Electric bills climb in summer despite no change in thermostat settings. When a radiant barrier stops reflecting, your AC picks up the full heat load of the attic. In Houston, that’s a measurable jump: we’ve seen bills step up $40 to $80 a month from June through September after barrier failure.
- Moisture spots or mildew smell in attic insulation. This is the non-perforated foil problem I mentioned. If someone installed a solid foil over insulation without checking attic ventilation, moisture gets trapped. You’ll smell it before you see it.
- Foil is dark, coated in dust, or has lost its shine. Radiant barrier works by reflecting radiant heat. A dirty, dust-caked, or oxidized foil surface reflects far less. In Houston attics with decades of dust accumulation, we sometimes see foil that has lost up to 60% of its original reflectivity.
Replacement Cost & What’s Included
Most Demilec-compatible radiant barrier installation jobs in Houston run between $0.90 and $1.60 per square foot for a typical attic, with the final number depending on attic height and access, whether we’re removing failed material first, and how much of the existing insulation needs attention before we lay foil. A 1,500-square-foot attic typically lands between $1,400 and $2,400, all in. A cramped attic with a 4-foot peak and tight clearance might push toward the top of that range, while an open, walkable attic is faster and lands lower.
You get a written price before we start, no exceptions, and that price covers the foil material, staples and flashing, labor, and cleanup. Every installation carries our 365-Day Done Right Promise in writing: if it’s not right within a year, we come back and fix it at no charge. Glenn Hartley’s crews don’t leave an attic messier than they found it, and that’s part of the Kingswell Guarantee, right alongside the committed arrival window.
DIY or Call Us?
Radiant barrier installation is, honestly, one of the safer attic projects. You’re not dealing with high-tension springs, electrical wiring, or pressurized chemicals. The risks are falling through the ceiling by stepping between joists, heat exhaustion in a Houston attic that’s 140°F in the summer, and getting the ventilation details wrong. None of those are worth learning about the hard way.
What you can safely do yourself: check your existing foil for labels, measure the width, look at whether it’s perforated, and figure out your attic’s rough square footage. That gives us a head start on your estimate. What we’d recommend against is crawling through a hot attic with a staple gun, trying to get the foil flat over uneven joists, and figuring out the soffit ventilation clearance on your own. A poorly installed barrier isn’t just less effective, it can trap moisture and cause the exact problems you’re trying to solve. If you want to talk through what you’ve got before deciding, call (903) 447-8369. We’ll tell you honestly whether it’s worth paying us or whether you’re better off spending the money on different insulation work entirely.
FAQs
A properly installed Demilec radiant barrier in a Houston attic typically lasts 15 to 25 years before reflectivity drops enough to matter. Houston’s dust and humidity are the main enemies, not the foil itself. Perforated foil over insulation tends to last longer than non-perforated because it doesn’t trap moisture. Call (903) 447-8369 for an inspection and an honest assessment of what’s left in your current barrier.
Yes, when the failure is localized, such as a torn section from AC service or sagging foil in one section of rafters. We can patch and re-staple isolated areas for a fraction of full replacement cost. If the foil is heavily dust-coated across the whole attic or moisture has been trapped underneath for years, replacement usually costs about the same as a proper repair and performs better long-term.
A typical 1,500-square-foot Houston attic takes one crew between 3 and 5 hours for a laid-over-insulation install, and 6 to 8 hours when we’re stapling to rafters. Older attics with tight clearance or lots of obstacles add time. We’ll give you a committed arrival window and a straight answer on how long the job will take when we price it.
We stock perforated and non-perforated radiant barrier foil on the truck, including Demilec-compatible products and other brands like Reflectix. For most Houston attics, we have what we need on hand the day we arrive, which is why same-day installation is realistic for many jobs. Call (903) 447-8369 and we’ll tell you exactly what we’d use in your attic and why.
Written by Glenn Hartley, Owner, Woolsey Insulation Houston at Woolsey Insulation Houston, serving Houston and nearby areas.