Radiant barrier cost

Two named listings, read on the same day. Nothing here is averaged, and nothing is filled in where a seller publishes no figure.

Figures: material only. No labor, no fasteners, no delivery. Both prices are shelf or list prices read on 2026-08-11. The roll area is worked out from the roll dimensions in the product name, so 48 inches wide by 125 feet long is 500 square feet.

The gap is the finding. Two rolls of the same width, the same length and the same 500 square feet, priced about 1.6 times apart on one day. Foil is not one commodity with one price. Weight, backing and perforation all differ between products, and so does what the seller charges to ship it. So price the exact roll you are buying, on the day you buy it.

One column is missing from that table on purpose, and it is the one most product pages lead with. There is no dollars-per-square-foot-at-R-30 figure for foil. A radiant barrier reflects radiant heat rather than resisting conduction, so it has no useful R-value per inch and cannot be counted toward an R-value target. It is measured differently from bulk insulation and the two do not add together. Bulk insulation gets priced at a target R-value because you buy more of it to go deeper. Foil is one sheet at one thickness. There is no deeper version to buy, so there is no per-R price to quote. Insulation cost per square foot prices every other material that way and leaves this one blank for the same reason.

This is where a budget goes wrong. You do not buy foil by the size of your ceiling. Stapled under the rafters, the foil follows the roof plane, and a sloped plane covers more surface than the floor beneath it.

The size of that difference is set by your roof pitch, which is the rise in inches for every 12 inches of horizontal run. A rafter is the long side of a right triangle whose base is the run and whose height is the rise. So the multiplier is arithmetic on your own pitch, and nothing else.

This site does not publish one multiplier for all houses, because it holds no figure for a typical roof pitch and will not invent one. Find your own pitch instead, then read the factor off this table.

Geometry on a stated pitch, not a survey of houses. It covers the two sloped planes only. A gable end wall, a dormer cheek or a hip return is extra area, and none of them follow from the pitch. Measure the rafter run in your own attic if you want the exact number.

Three ways to find your pitch without a ladder. Lay a level in the attic against a rafter and measure the drop over 12 inches. Count the vertical rise across the width of a gable end from outside. Or ask whoever last roofed the house, because the pitch is on the estimate.

The roll count, worked

Figures: material only, at $77.59 a roll for 500 square feet, read 2026-08-11. Roof surface at a 6 in 12 pitch, which is an assumption about the house rather than a measurement of it. Rolls are rounded up, because a roll is the unit you buy.

Read the last two columns together. The foil is $0.16 a square foot on the roll, but by the time it is spread over the roof above a 1,200 square foot ceiling it is $0.19 a square foot of ceiling. Same product, different denominator. That is the number to compare against any other attic spend, and it is the number a quote should be checked against.

Two rows share a roll count, and that is not an error. Foil is sold 500 square feet at a time, so the cost steps up in jumps while the roof area rises smoothly. The last column wobbles for the same reason. On a roof that lands just over a roll boundary you pay for foil you do not use.

Add for overlap and offcuts on top of that. Strips get lapped at the seams and trimmed at the ridge and the eaves. This site publishes no waste allowance, because none has been measured here. Buying the roll count in the table with nothing spare is how a job stops two rafter bays short.

The same roof at the manufacturer-direct price is 3 rolls and about $375 before shipping. On a whole attic the spread between the two listings is real money, so it is worth pricing both before ordering.

This site holds no measured installed price for a radiant barrier, so it publishes none. That is a limit, not an oversight, and it is worth being plain about.

The cost model here prices one job: blowing loose fiberglass onto an attic floor. Its labor line is 9 to 12 crew-hours per 1,000 square feet, at the BLS May 2025 mean wage for insulation workers of $26.32 an hour, times 2.0 to 3.0 for what a worker costs beyond pay. Those hours describe a crew working a hose across a floor. Stapling sheet overhead between rafters is different work, in a worse position, and nothing here measures it. Borrowing the blown-in figure would produce a confident number with nothing behind it.

So judge the quote instead of comparing it to an average. Four steps, and they end in a verdict.

1. Ask which area the price counts. Roof plane or attic floor. They are different numbers on the same house, and a quote that names neither cannot be checked.
2. Ask for the material line on its own, with the product name and the roll size on it. That is the half you can verify in an afternoon.
3. Divide the material line by the square feet of foil. Compare the answer with $0.16 to $0.25. A contractor buys below shelf price, so under the low end can be honest. Well over the high end needs a reason.
4. Verdict. What is left is labor, access and profit. This page cannot tell you whether that share is fair, and it will not pretend to. Get a second itemized quote and compare the two labor lines against each other, because that is the only comparison available here.

One thing worth knowing before you price the labor. This is overhead work in the hottest space in the house, standing on framing with no floor. Contractors doing it work under OSHA fall protection and breathing protection rules. A homeowner in their own attic is outside those rules entirely, and the risk is the same either way.

There are two retrofit ways to fit foil, and they do not cost the same or work the same. The cheaper one is the one that fails.

Here is why the cheap version loses. Foil works because its surface gives off very little infrared heat. Household dust is an ordinary surface that gives off heat freely. So a layer of dust on an upward-facing sheet slowly turns it back into an ordinary surface. Nobody climbs up to clean it, and nothing warns you it has happened.

Three more problems come with the floor version, and they are not about dust. Where the foil touches the insulation there is no air space, so at those points it carries heat rather than reflecting it. Laid flat it sits on the cold side of the insulation in winter, where a vapor-tight sheet can hold moisture in the layer below. And it hides the insulation, so nobody can measure the depth or top it up later without pulling it all back.

Perforated products, including both rolls priced above, let moisture through and fix the vapor problem only. They do nothing about the dust, the contact points or the inspection problem. So the cheaper area is not a saving. It is a smaller purchase that does less. Radiant barrier works through all three installation methods in full, including foil-faced roof sheathing, which is the version worth catching if your deck is coming off anyway.

Three things a radiant barrier does not do, whatever it cost. Each one is a reason a cheap roll can still be the wrong purchase.

• It adds no R-value to your ceiling. A radiant barrier reflects radiant heat rather than resisting conduction, so it has no useful R-value per inch and cannot be counted toward an R-value target. It is measured differently from bulk insulation and the two do not add together. So foil cannot close a gap between what your attic has and what your zone calls for. Adding it to an R-value total is arithmetic on two different quantities.
• It does not replace insulation. Bulk insulation slows heat conducted through the ceiling in both directions, all year. Foil intercepts radiant gain from a sun-heated roof deck, which is a summer daytime effect. A house with foil under the rafters and a thin ceiling still loses heat straight up every winter night.
• It does not fix air leaks. Air moving through gaps around light fittings, plumbing stacks and the top plates is a separate loss, and often the larger one. U.S. Department of Energy guidance treats sealing the ceiling plane as the job that comes first. Air sealing sets out the order of work.

There is also no dollar saving published on this site for a radiant barrier, and there will not be one until something is measured. Predicting a bill takes energy prices, degree days and the way a house is run, and none of those are held here.

Find the row that matches your house. Where two rows could apply, the one describing a ceiling short of depth wins, because depth comes first in every case. The re-roof row is an opportunity rather than a priority, so it applies alongside whatever your first row said.

Levels are ENERGY STAR retrofit guidance for an existing home, based on 2021 IECC Residential Provisions Table R402.1.3. Energy codes cover new building and work done under a permit. They do not usually cover adding insulation to an attic you already have. Which edition applies where you live depends on your state, and often on your city. Your local building department is the only authority on it. Climate zones are the 2021 IECC map. The ZIP lookup finds your zone.

Those verdicts are the same ones the radiant barrier page reaches from the physics. This page only adds the prices. A hot climate, a dark roof in full sun, ducts in the attic and a ceiling already at depth is the one combination worth the money, because heat picked up by the ducts never passes through your ceiling insulation on its way indoors.

If your row said fix the depth first, that is the work to get priced. Attic insulation cost builds that total from wages, coverage and crew hours, and names the basis of every input. Blown-in insulation cost prices the depth work per bag and per square foot. The gear list covers what an attic job takes. It does not list radiant barrier products at all, and it says why.

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We do not sell insulation and we do not install it, which is why this section exists. For most attics the same money does more somewhere else, and the roll being cheap is not the point.

Figures: material only, at shelf and list prices read on 2026-08-11 and 2026-08-07, on a 1,200 square foot attic floor. Foil is priced over the roof plane at a 6 in 12 pitch. Blown fiberglass is Owens Corning AttiCat blown-in fiberglass, 27.5 lb bag, priced from its published coverage chart. No labor is in any of these.

Read that as two different purchases, not as a cheap option and an expensive one. They are not substitutes. Material to R-30 costs about 5 times the foil job on this attic, and R-60 costs more again. What the extra money buys is the R-value the foil does not have. Buying the cheap thing does not get you a fraction of the expensive thing. It gets you a different thing.

Three cases where the answer is to spend nothing here.

• Your ceiling is short of depth. Fix that first, in every zone. Heat flow falls as one over R, so the first inches over a thin ceiling do far more than any later step. The depth checker turns your measured inches into an R-value range before you spend anything.
• You are in a cold zone. The load that costs you money is heat leaving through the ceiling on winter nights, which is conduction and air leakage. Foil addresses neither. A reflective air space also works least well when heat is moving upward, which is exactly the winter direction.
• You are already near your target. Within about R-10 of the ENERGY STAR level for your zone, more depth pays back slowly and air sealing usually beats it. That R-10 line is this site's editorial judgment, labeled an estimate rather than a measurement. In a hot zone with ducts overhead, that is also the point where foil becomes the more interesting purchase.

Every radiant barrier is sold on a big percentage. This page carries none, and the reason is worth stating.

Two product pages for the identical model number state different reflectivity claims. Neither publishes an emittance figure. That is the property actually doing the work: a number from 0 to 1 showing how readily a surface gives off infrared heat. Clean bright aluminum sits near the bottom of that scale, and ordinary surfaces such as wood, kraft paper and dust sit near the top.

There are standards for measuring it, and a technical data sheet should cite one. ASTM C1371 measures emittance with a portable meter, and ASTM E408 does it by an inspection-meter method. ASTM C1313 is the material specification sheet radiant barriers are sold against. ASTM C1363 tests a whole assembly in a hot box, with the air space and the direction of heat flow included, which is the only setting where a reflective product can carry an honest R-value.

A reflectivity number on a box describes foil as it left the factory, clean and in a lab. It is usually accurate about the surface. It says nothing about a house, and nothing about the same surface after a year in an attic. Compare that with the price, which two people can check on the same day and get the same answer.

The FTC R-value Rule (16 CFR Part 460) governs how R-values may be advertised for home insulation, and it is why a bag of loose fill carries a coverage chart while a roll of foil reaches for different words. R-value itself is measured by conduction tests such as ASTM C518, run on a sample of stated thickness. Run one on a few thousandths of an inch of foil and there is almost nothing there to resist heat.

• Radiant barrier: what it does, and the narrow case for it
• Insulation cost per square foot, by material
• Attic insulation cost, installed
• What R-value your zone calls for
• Air sealing, the job that comes first
• Attic ventilation, which staple-up must not block