Frequently Asked Questions

Choose Laser Perforated (LP) for most attic and roof-rafter applications, especially when you are unsure. Choose Vapor Barrier (VB) when the project intentionally requires a vapor barrier, radon barrier, or very low perm layer.

Laser Perforated (LP) is perforated, so moisture vapor has a path through the material. That makes it more forgiving in many residential attic situations where accidentally trapping moisture would be a bad outcome.

Laser Perforated (LP) is the normal choice for a vented attic in a hot, humid climate because it controls radiant heat without creating an unintended non-perforated vapor barrier. Use Vapor Barrier (VB) only when its location and vapor-control role are deliberately designed for the complete assembly. Compare LP and VB in detail.

For common 16 inch on-center framing, the 17 inch roll is easier to manage. For common 24 inch on-center framing, the 25.5 inch roll works well. Wider 51 inch rolls cover open areas faster but are heavier to handle overhead.

A radiant barrier is a low-emittance reflective material that reduces radiant heat transfer across an adjacent air space. It works alongside conventional insulation: insulation slows conductive heat flow, while the radiant barrier reduces radiant heat exchange.

No. Radiant barrier and bulk insulation control different forms of heat transfer and normally work together. A radiant barrier should not be assigned an R-value by itself when it is installed without the tested air space and assembly on which that R-value depends.

Yes. Ra-flect is reflective on both sides, so there is no required front or back orientation. For radiant performance, at least one reflective face must border an adjacent air space. If both faces are sandwiched tightly between other materials, radiant performance is reduced.

Dust can reduce the radiant performance of the surface it covers because the dust becomes the surface facing the air space. It does not permanently remove the reflectivity of the aluminum beneath it. This is a serious limitation for a single-sided product when its only reflective face collects dust.

Ra-flect is reflective on both sides. In an under-rafter installation, the sheltered downward-facing surface remains clean and continues facing an air space even if dust settles on the upper surface. The system therefore retains an effective reflective surface. Heavy dust can still matter in a horizontal attic-floor installation because the lower face is usually against the insulation and does not have an adjacent air space. This is one reason under-rafter installation is preferred when practical.

Reflectivity describes how much radiant energy a surface reflects. Emissivity describes how readily that surface emits absorbed heat. For an opaque surface, high reflectivity corresponds to low emissivity. Ra-flect’s 95% reflectivity is paired with a low-emittance, oxidation-protected surface for durable radiant performance.

Savings vary with climate, roof exposure, attic ventilation, insulation, duct leakage, HVAC location, energy prices, and installation quality. Radiant barrier can reduce radiant heat gain and cooling load, but a responsible estimate should not promise a fixed utility-bill percentage for every home.

Often yes, but keep ventilation clear and use Laser Perforated (LP) unless your design specifically calls for a vapor barrier. Climate, existing ventilation, and moisture control matter.

Many homeowners install radiant barrier in accessible attics. Pre-cut manageable lengths, use stable work boards and adequate lighting, protect yourself from heat and dust, preserve ventilation paths, and maintain required clearances from flues, chimneys, recessed fixtures, wiring hazards, and other heat-producing equipment. Use a qualified contractor when access or the assembly is complex. Review the installation methods.

Either side. Ra-flect is reflective on both sides, so there is no front or back orientation. At least one side must face an adjacent air space for radiant-barrier performance.

Not for a typical vented attic radiant-barrier installation. Overlap runs or meet them at framing and keep ventilation open. Tape seams only when air sealing or vapor-barrier continuity is an intentional part of the assembly design.

Roof coverage is greater than the home’s floor area because roof pitch and overhang add surface area. Use the Material Calculator on this site; it includes pitch, overhang, 10% installation waste, and recommends an efficient combination of available roll sizes.

Checkout calculates ground shipping from each selected roll’s package size and weight and the delivery address. The carrier may vary by order.

Reflectivity alone is not the whole story. Unprotected aluminum can oxidize in attic heat and humidity, reducing reflective performance over time. Ra-flect uses coated material selected to resist oxidation and maintain 95% reflectivity.

The fire-test mounting method is also critical. Beginning with the 2012 code cycle, reflective insulation and radiant barrier materials tested under ASTM E84 were required to use the ASTM E2599 specimen preparation and mounting method. This tested the complete material in a configuration representative of its installed use instead of allowing the older mounting approach. The change meant that legacy 97% products made by applying reflective aluminum to polyester film, often described as Mylar-type foil, could no longer rely on their earlier Class A/Class 1 results and did not qualify under the required E2599 mounting method.

When comparing radiant barriers, ask for an ASTM E84 report for the product as sold with specimen preparation and mounting in accordance with ASTM E2599. Applicable IBC and IRC provisions generally limit insulation materials to a flame-spread index of 25 or less and a smoke-developed index of 450 or less. Ra-flect is rated Class A/Class 1 with a flame-spread index of 0 and smoke-developed index of 10 under ASTM E84/E2599.