Radiant barrier foil costs roughly $0.09 to $0.20 per square foot in materials at retail. Installed by a contractor, expect somewhere around $0.35 to $0.75 per square foot depending on access and region. The gap is labour in a hot attic, which is genuinely unpleasant work.
Materials, from live prices
Dividing real roll prices by their coverage gives the actual per-square-foot cost:
| Product | Roll price | Coverage | Per sq ft |
|---|---|---|---|
| RadiantGUARD Xtreme, 1,000 sq ft reflective foil roll | $199 | 1,000 sq ft | $0.20 |
| Reflectix radiant barrier, 4 ft x 250 ft perforated (1,000 sq ft) | $148.88 | 1,000 sq ft | $0.15 |
| Radiant barrier perforated aluminium, truss/rafter roll | $158.27 | 1,000 sq ft | $0.16 |
| SmartFOIL double-sided perforated, reinforced | $87.95 | 500 sq ft | $0.18 |
| VEVOR double reflective perforated woven roll | $69.90 | 500 sq ft | $0.14 |
Live Walmart prices checked 2026-08-29. Per-square-foot figures are ours, calculated from the roll price and stated coverage.
Why the range is so wide
The cheap end is single-layer foil on a scrim. The expensive end is double-sided, reinforced, or foam-cored product that is doing more than one job. For attic radiant barrier specifically, the cheap single-layer perforated product is the right buy: you are paying for emittance, and a $0.09/sq ft foil and a $0.20/sq ft foil both sit at roughly 0.03 to 0.05 emittance.
Foam-core products are a different category. They add genuine R-value and cost several times more per square foot. If you want R-value, blown-in insulation buys far more of it per dollar.
The number that actually matters
Per square foot of foil is not per square foot of house. Because rafter area exceeds floor area, a 1,500 sq ft attic needs about 1,845 sq ft of material. At $0.15/sq ft that is $297.76, so the cost per square foot of conditioned space is nearer $0.20.
| Attic floor area | 1,500 sq ft |
| × slope factor for 6/12 pitch | × 1.118 |
| = rafter area to cover | 1,677 sq ft |
| + 10% for overlap, offcuts and obstructions | 1,845 sq ft |
| ÷ 1,000 sq ft per roll, rounded up | 2 rolls |
| 2 × $148.88 (Reflectix radiant barrier, 4 ft x 250 ft perforated (1,000 sq ft)) | $297.76 |
| 3 × $17.85 foil tape (2 in x 30 ft) | $53.55 |
| Hammer tacker (Arrow HT55 hammer tacker) | $27.99 |
| Materials total | $379.30 |
DIY versus installed
Contractor quotes for attic radiant barrier commonly land between $0.35 and $0.75 per square foot installed, and the spread is driven by attic access more than anything else. A walk-in attic with 6 ft of headroom quotes very differently from a 30-inch crawl space over a finished second storey.
We do not quote installed prices as our own figures, because NailIt estimates materials only, on the assumption you are supplying the labour. What we can tell you precisely is the materials side, and that is what the estimator returns.
Price your own attic in 30 seconds → Free, no account for your first estimate.
See also the complete radiant barrier guide and how much you need for a 1,500 sq ft attic.