Attic Foil Insulation

Stop Heat Gain. Retain Comfort. Save Energy.

ES® attic foil insulation (radiant barrier for attic) reflects radiant heat to improve year-round comfort, lower energy bills, and support energy-efficient home insulation. Installed beneath the roof rafters, it prevents unwanted heat from entering your living spaces in summer and reduces heat loss in winter. In roof systems where radiant barriers are installed above the roof deck, radiant barrier roofing insulation can stop solar heat before it enters the attic space.

Reflects radiant heat to improve year-round comfort and reduce energy bills.

Installed beneath the roof rafters, it keeps unwanted heat out in summer and retains warmth in winter, supporting a more energy-efficient home.

ES® radiant barrier attic foil insulation reflecting heat to block attic heat gain

Block Radiant Heat in Your Attic

Attics are one of the biggest sources of energy loss in homes. Radiant barriers reflect heat away from your attic, keeping your home cooler and more energy-efficient.

Photorealistic cutaway of a residential attic in winter showing a radiant heat barrier foil installed beneath the roof deck, reflecting warm indoor air back into the home and reducing heat loss.

Reduce Heat Loss

A properly installed roof radiant heat barrier under roof decking reduces attic heat buildup and improves HVAC efficiency.

Perforated attic foil insulation allowing airflow to prevent moisture and mold

Improve Air Circulation and Prevent Moisture

Perforated ES® attic foil insulation allows air to circulate, stopping moisture from collecting and preventing mold and mildew. This protects your roof structure and insulation, contributing to a healthier, more energy-efficient home.

Cutaway of attic showing ES® radiant barrier foil insulation reflecting infrared heat, reducing heat transfer, and controlling moisture.

How Reflective Attic Insulation Works

Radiant barrier insulation works by reflecting infrared energy back toward its source. When installed with an air space, it limits heat transfer through attic ceilings and walls while also acting as a vapor barrier to reduce condensation.

While attic insulation helps control heat entering from above, basement insulation also plays a critical role in reducing heat loss and moisture from below, supporting overall home energy efficiency.

Key Technical Benefits:

  • Reduces radiant heat transfer
  • Reflects infrared energy
  • Air space ensures optimal performance
  • Improves overall energy efficiency in the attic

Homes with vaulted or sloped roof assemblies without attic space often require cathedral ceiling insulation, where reflective insulation is installed directly beneath the roof deck.

Will Attic Foil Insulation Affect Wi-Fi or Cell Phone Signals?

Many homeowners ask if installing foil insulation in their attic will interfere with Wi-Fi or cell phone reception.

In most homes, the answer is no—your signal should continue to work normally.

Attic foil insulation (radiant barrier) uses reflective aluminum surfaces that can interact with radio frequencies. However, in a typical installation:

  • The attic is not fully sealed or enclosed with foil
  • Signals can still pass through walls, windows, and openings
  • Wi-Fi signals naturally reflect and bounce throughout the home

Because of this, there is no noticeable impact on everyday connectivity in most residential settings.

When Can Signals Be Affected?

  • Fully enclosed metal buildings
  • Structures wrapped completely in foil or metal layers
  • RF-shielded or secure environments

These conditions are not typical in standard attic installations.

ES® Attic Foil Insulation Products

ES® Attic Foil Insulation Products

High-performance foil radiant barrier insulation engineered to reflect up to 97% of radiant heat. Designed for applications where controlling radiant heat transfer is critical.

RFID Radiant Barrier Foil.

Key Features

  • High-reflectivity foil designed for attic spaces
  • Reflects up to 96% of radiant heat
  • Perforated surface allows moisture to escape
  • Works beneath roof rafters or over existing insulation
  • Lightweight, durable, and easy to install

Reflective foam insulation features a closed-cell polyethylene core with foil on both sides, reducing radiant and conductive heat transfer. It also helps control moisture and supports long-term energy efficiency.

Roll of ES® RFID reflective foam with foil on both sides

Key Features

  • Dual-sided foil insulation with rigid foam core
  • Reflects heat while reducing conductive heat loss
  • Adds strength and moisture resistance to attic assemblies
  • Flexible, easy to cut, and retrofit-friendly

INSTALLATION OPTIONS

Installation varies based on roof type, climate zone, and building design.

Under Rafters

Perforated radiant barrier installed under the rafters of an attic with fiberglass insulation on the floor of the attic.
  • Installed beneath roof rafters for maximum radiant heat reflection
  • Works with existing attic insulation
  • Ideal for new construction or retrofits

Over Existing Insulation

Cutaway view of a residential attic showing a smooth, reflective radiant barrier foil laid horizontally over existing fiberglass insulation on the attic floor, with clear wooden rafters and roof decking above.
  • Laid horizontally over existing insulation on the attic floor
  • Enhances performance of traditional insulation
  • Easy to install without major renovation
  • Maintains airflow and prevents moisture buildup

Tested and Code-Compliant

✔ ASTM E84 Fire Performance
✔ ASTM E2599 Radiant Barrier Performance

Designed for long-term thermal performance without maintenance.

Radiant barrier foil attic insulation reflecting heat to improve energy efficiency and temperature control

Benefits of Energy-Efficient Attic Insulation

  • Lower cooling costs: Blocks summer heat from entering your home
  • Reduce heating demand: Reflects winter heat back indoors
  • Moisture control: Prevents condensation and mold growth
  • Supports HVAC efficiency: Less strain on heating and cooling systems, especially when attic ducts are protected with ductwork insulation.
  • Protects your roof structure: Extends lifespan of roof assemblies

For full building envelope efficiency, attic insulation should work alongside reflective house wrap insulation to control heat transfer through exterior walls.

Energy Shield USA reflective insulation improving energy efficiency and indoor comfort

Why Choose Energy Shield USA® Radiant Barrier Roofing Insulation?

USA-made, precision-engineered materials
Millions of square feet in stock
Fast shipping nationwide
Proven performance in real-world applications
Trusted by builders, contractors, and homeowners

Attic Foil Insulation FAQs

What is attic foil insulation?

Attic foil insulation is a reflective material installed beneath roof rafters to reduce radiant heat transfer. It keeps homes cooler in summer, warmer in winter, and supports energy-efficient attic systems

How does radiant barrier insulation for attic work?

Radiant barrier insulation reflects heat away from your living space, reducing attic heat gain in summer and retaining warmth in winter. It lowers energy costs and eases HVAC demand.

Can attic foil insulation prevent moisture and condensation?

Yes. Perforated foil insulation allows air to circulate, preventing condensation, mold, and mildew while protecting your attic structure.

Is radiant barrier for attic effective in all climates?

Yes. It is particularly beneficial in hot climates to block solar heat but also improves winter energy efficiency by reflecting heat back into your home.

Can I install radiant barrier insulation with existing attic insulation?

Yes. ES® attic foil insulation can be installed above existing insulation or beneath rafters for enhanced thermal performance without major renovation.

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