The best radiant barrier for most attics is a pure aluminum foil rated at 95% or higher reflectivity with a surface emittance at or below 0.05, installed as a perforated (breathable) sheet. Our top pick is AtticFoil Original Double-Sided Perforated, because it is a true radiant barrier with no filler layers, blocks about 97% of radiant heat per the manufacturer, and comes in three widths that fit standard rafter and truss spacing. Below we rank six products by job type, list real specs and prices as of July 2026, and explain the two spec details (perforation and emittance) that decide whether a barrier actually performs.
How we picked, and what we did not do: we did not lab-test these products. Rankings are based on published manufacturer and retailer specifications, the ASTM test methods those specs cite, U.S. Department of Energy guidance on where radiant barriers pay off, and documented buyer feedback. Reflectivity and emittance figures are the makers’ own numbers, verified to ASTM C1371 (the test method for emittance) and measured against ASTM C1313 (the sheet radiant barrier specification, which requires an emittance of 0.10 or lower). Treat performance claims as conditional on correct installation and your climate.
What actually makes a radiant barrier work
A radiant barrier works by reflecting infrared heat across an air gap, not by slowing conduction the way fiberglass or foam does. When the sun heats roof decking, the underside radiates that heat downward. A foil facing an air space bounces most of it back, so the attic floor and rooms below stay cooler. This is why a radiant barrier has an emittance rating, not an R-value, and why it needs an air gap facing the reflective side to do anything.
Two numbers matter. Emittance (emissivity) is how much heat the surface radiates: lower is better, and premium foils sit around 0.03 to 0.05. Reflectivity is the mirror of that: the best foils reflect 95% to 97% of radiant heat. ASTM C1313 sets the pass mark at an emittance of 0.10 or lower, so any product above that line is not a qualified radiant barrier no matter how it is marketed.
Do radiant barriers save enough to bother?
In warm, sunny climates a radiant barrier can cut cooling costs by 5% to 10%, according to the U.S. Department of Energy, and the effect is largest when HVAC ducts run through the attic. In cool climates the DOE recommends adding conventional insulation instead, because there is little summer heat to reject and a barrier does not add meaningful winter R-value. Manufacturers report attic-temperature drops of up to 30F after installation, which is a comfort and duct-load benefit more than a guaranteed dollar figure. Savings vary by climate zone, roof color, duct location, and existing insulation, so treat the 5% to 10% band as a ceiling for hot climates, not a promise.
Best radiant barriers for roofing and attics (2026), ranked
Here are six products ranked by the job they suit best. Five are true reflective foils; one (Reflectix) is a bubble product we include because buyers cross-shop it, with a clear note on where it fits. Prices are material only, as of July 2026, and exclude staples, tape, and labor.
| Product | Type | Reflectivity (maker) | Widths | Breathable? | Approx. price | Best for |
|---|---|---|---|---|---|---|
| AtticFoil Original (perforated) | Pure double-sided foil | ~97% | 26″, 48″, 60″ | Yes (perforated) | ~$0.15 to $0.30 / sq ft | Whole-attic staple-up, best overall |
| RadiantGUARD Xtreme (X-1000-B) | Reinforced woven-scrim foil | ~95% (ASTM C1371-15) | 26″, 48″ | Yes (perforated) | ~$185 / 1,000 sq ft | Heavy-duty, high-traffic attics |
| ARMA FOIL High Strength | Pure double-sided foil | ~95% | 17″, 25.5″, 51″ | Yes (perforated) | Mid-range roll pricing | Joist-cavity fit, least cutting waste |
| EcoFoil Perforated | Pure double-sided foil | ~95% to 97% | 48″ (4′ x 125′, 500 sq ft) | Yes (perforated) | Budget roll pricing | Small jobs and value buyers |
| Innovative Insulations Super R Diamond | Perforated diamond-pattern foil | ~95%+ | 48″, 60″ | Yes (perforated) | Value roll pricing | DIY lay-over-insulation alternative |
| Reflectix Double Reflective | Double-bubble reflective | ~95% (reflective face) | 16″, 24″, 48″ | No (solid) | Big-box roll pricing | Ducts, garage doors, small gaps only |
1. AtticFoil Original Double-Sided Perforated (top pick)
AtticFoil Original is our top pick because it is a pure radiant barrier foil with no bubble or fiberglass filler, and the extra layers on cheaper “reflective insulation” add almost nothing to radiant performance. The maker rates it at about 97% radiant heat blocking, it is offered in 26″, 48″, and 60″ widths to match truss and rafter spacing, and the perforated version lets water vapor pass so it can be stapled to rafters or laid over existing insulation without trapping moisture. It carries ENERGY STAR listing and cites DOE study results. Best for a homeowner doing a full-attic staple-up who wants the most reflective surface per dollar.
2. RadiantGUARD Xtreme (best heavy-duty)
RadiantGUARD Xtreme is the pick when the barrier will get walked on or handled roughly. It uses an industrial woven-scrim middle layer for puncture and tear resistance, is about 6.5 mils thick, reflects roughly 95% of radiant heat verified to ASTM C1371-15, and carries a Class A / Class 1 fire rating that exceeds ASTM C1313. A 1,000 sq ft roll (4′ x 250′) runs about $185 at major retailers as of July 2026. Best for high-traffic attics, lay-over-insulation installs, and anyone who wants durability over the lowest price.
3. ARMA FOIL High Strength (best fit, least waste)
ARMA FOIL earns its spot on width strategy. It comes in 17″, 25.5″, and 51″ widths sized to drop into 16″ and 24″ joist and rafter cavities with little cutting, which saves material and time on staple-up jobs. It is a pure double-sided foil rated around 95% reflectivity, so radiant performance is in the same class as the top picks. Best for installers fitting foil between framing members who want to minimize offcuts on a large attic.
4. EcoFoil Perforated Radiant Barrier (best budget)
EcoFoil is the value play for smaller areas or a first test section. It is a perforated double-sided foil sold in a 4′ x 125′ (500 sq ft) roll, rated in the 95% to 97% reflectivity range, and priced below the reinforced products. It reflects heat as well as pricier foils; what you give up versus RadiantGUARD Xtreme is the scrim reinforcement and heavy-duty feel. Best for garages, a partial attic, or a homeowner buying one roll to try before committing.
5. Innovative Insulations Super R Diamond (DIY alternative)
Super R Diamond is a perforated diamond-pattern foil aimed at do-it-yourself lay-over-insulation jobs. It is breathable, easy to roll out across an existing insulated attic floor, and priced in the value tier. Reflectivity sits in the mid-90s percent range like other pure foils. Best for a DIYer who wants a lay-down (not staple-up) install and prefers a perforated sheet designed for that method.
6. Reflectix Double Reflective (small jobs only)
Reflectix is the double-bubble product most people see first at a big-box store, and it belongs at the bottom of a roofing list on purpose. The reflective face does reflect radiant heat, but it is solid (not perforated), thin, and reviewers report it tears easily, so it is a poor choice for a full attic where breathability and coverage matter. Best kept to ductwork, water heaters, garage doors, and small gaps where its rigidity and narrow rolls are an advantage.
Perforated vs solid: which do you need?
Choose perforated (breathable) foil for almost any attic application, and reserve solid foil for a deliberate vapor barrier. A radiant barrier stapled to rafters or laid over insulation must let water vapor escape, or moisture can condense against the foil and wet the insulation below. Perforated sheets have tiny holes that pass vapor while keeping nearly all the reflective surface working. Solid, non-perforated foil is a true vapor barrier and should only go where you want to block moisture, such as a house wrap or crawl-space ground cover, not laid on an attic floor.
Single-sided vs double-sided: does it matter?
For reflecting attic heat, single-sided and double-sided foil perform about the same, because only the face pointing at the air gap does the reflecting. The reason to pick one is the install method, not the physics. Double-sided foil is the default for staple-up between rafters, since either side can face the gap and it looks finished from below. Single-sided foil is usually a house wrap for new construction or renovation, where the reinforced backing matters. Do not pay a premium for double-sided if your install only exposes one face.
How much does a radiant barrier cost?
Material for name-brand pure foil generally runs about $0.15 to $0.40 per square foot, so a 1,500 sq ft attic in foil costs roughly $225 to $600 in material before staples and tape. Reinforced products like RadiantGUARD Xtreme sit at the top of that band, around $185 per 1,000 sq ft, while value foils like EcoFoil sit lower. Professional installation adds labor and typically lands the total well above a DIY staple-up. Because DOE-cited savings top out near 5% to 10% of cooling cost in hot climates, the payback math favors a DIY install in a warm zone with attic ducts and works against paying for pro labor in a mild climate.
The bottom line
For a full attic in a hot, sunny climate, buy a perforated pure foil: AtticFoil Original for the best reflective surface per dollar, RadiantGUARD Xtreme if the barrier will take abuse, and ARMA FOIL if cavity fit and low waste matter most. Skip bubble products like Reflectix for whole-attic coverage and keep them for ducts and small gaps. And confirm the two specs that decide everything: an emittance at or below 0.05 and a perforated sheet, unless you specifically want a vapor barrier. Pair the foil with sound attic ventilation and adequate attic insulation for the full effect; a radiant barrier complements those, it does not replace them.
For how radiant barriers sit alongside conductive insulation and R-value, see our guide to home insulation types. For the wider payoff of reflecting heat at the roof, our cool roof energy savings report breaks down savings by climate. On metal roofs, review where reflective layers belong in the metal roofing insulation and underlayment stack.
Frequently asked questions
Do radiant barriers really work?
Yes, in the right climate. The U.S. Department of Energy reports radiant barriers can lower cooling costs by 5% to 10% in warm, sunny climates, and the benefit is largest when HVAC ducts run through the attic. In cool climates the DOE recommends adding conventional insulation instead. A radiant barrier reflects infrared heat across an air gap, so it must face an open space to work and does not add meaningful winter R-value.
Perforated or solid radiant barrier: which do I need?
Use perforated (breathable) foil for nearly all attic installs. It lets water vapor pass so moisture does not condense against the foil and wet the insulation below, while keeping almost all of the reflective surface working. Reserve solid, non-perforated foil for places you deliberately want a vapor barrier, such as a house wrap or crawl-space ground cover, not laid on an attic floor.
Does a radiant barrier need to be double-sided?
No. Only the face pointing at the air gap reflects heat, so single-sided and double-sided foil perform about the same. Pick based on install method: double-sided is the default for staple-up between rafters because either side can face the gap, while single-sided foil is usually a house wrap for new construction. Do not pay extra for double-sided if your install exposes only one face.
Is Reflectix a real radiant barrier?
Reflectix has a reflective foil face that does reflect radiant heat, but it is a double-bubble product, not a pure perforated foil, and it is solid rather than breathable. That makes it a weak choice for a full attic, where reviewers also note it tears easily. It works well for ductwork, water heaters, garage doors, and small gaps, where its rigidity and narrow rolls help.
How much does a radiant barrier cost?
Pure foil material generally runs about $0.15 to $0.40 per square foot, so a 1,500 sq ft attic costs roughly $225 to $600 in material before staples and tape. Reinforced foils like RadiantGUARD Xtreme sit near the top, around $185 per 1,000 sq ft. Professional installation adds labor and raises the total well above a DIY staple-up, which is why hot-climate DIY installs show the best payback.
What reflectivity and emittance should a good radiant barrier have?
Look for at least 95% reflectivity and a surface emittance of 0.10 or lower, which is the pass mark under ASTM C1313. Premium foils reach roughly 0.03 to 0.05 emittance and 95% to 97% reflectivity, verified by the ASTM C1371 test method. Any product above 0.10 emittance is not a qualified radiant barrier regardless of how it is marketed.
Reviewed by The Roofing Brief Team. Last reviewed July 2026.