Radiant Barrier Buyers Guide

Radiant Barrier Key Concepts

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C1313 testing performed results in the following specifications which are important when comparing radiant barriers:

• surface emissivity (and conversely reflectivity)
• water vapor transmission
• surface burning characteristics (ie. flame spread & smoke development resulting in fire rating [see below]).
• corrosivity
• tear resistance
• adhesive performance
• fungal resistance

A radiant barrier that has been tested under the C1313 testing methods results in verified and comparable specifications that can be used to compare against other radiant barriers in the market.  These specifications help the consumer know what they are comparing and/or purchasing.

All RadiantGUARD® radiant barriers have been tested under ASTM C1313 and each product's specifications are listed on our website.

Reflectivity defines the amount of radiant heat is reflected away from the surface of the barrier facing a heat source.  Emissivity defines the amount of radiant heat that radiates from the surface of the barrier and it typically measured on the surface of the barrier facing away from the heat source.

Higher reflectivity ratings result in more radiant heat being reflected.

RadiantGUARD® radiant barriers have a reflectivity of 97% (and an emissivity of 3%).

Double-sided radiant barriers have two reflective surfaces, one on each side of the radiant barrier, allowing the radiant barrier to reflect radiant heat from both sides independently.

All RadiantGUARD® radiant barriers are double-sided.

In order for a radiant barrier to have durability and strength, a middle "scrim" layer is present in the center of the product.

The main differences in the three durability grades come down to the strength and tear resistance properties.

• Our Standard and Premium radiant barrier products have a scrim layer of woven polyethylene fibers. The scrim of the Premium is a tighter weave resulting in a more durable tear resistant radiant barrier than the Standard.  If your installation application does not require stapling, then our Standard or Premium radiant barrier is sufficient (the Premium is more tear resistant than the Standard).
• Our Ultima radiant barrier product is comprised of an almost solid scrim which makes it a much stronger product which allows it to hold staples and nails and not tear or pull through.   If your installation application requires stapling (ie. to attic rafters or wall studs), the Ultima radiant barrier is the recommended version as it is designed to hold up under staples due to the design of its scrim layer.

All RadiantGUARD® radiant barriers, regardless of durability, have a reflectivity of 97% .

In many cases, additional layers of raw material (fiberglass) makes the product more expensive. In addition, this added thickness makes it bulky and heavier which makes it more expensive to ship.  It also makes it more difficult to work with.

For example, our radiant barrier products are comprised on two outer reflective layers with a  middle scrim layer  which adds strength and durability. We consider this a three layer product; however some similar products are marketed as five layers because they count the adhesive bonding on both sides of the scrim as an independent layer.  We don't count glue as separate layers.

There are two organizations that provide fire ratings for building materials based on a products flame spread and smoke development results: The National Fire Protection Organization (NFPO) and The Uniform Building Code (UBC). NFPO's highest fire rating classification is "Class A." UBC's highest fire rating classification is "Class 1."

RadiantGUARD® radiant barriers products each have the Class A & Class 1 fire ratings.

Radiant barriers come either perforated or non-perforated (solid vapor barrier).

A perforated radiant barrier has small holes throughout the product that allow moisture vapor to pass through (click to view example).

A non-perforated (solid) radiant barrier has no holes and serves as a vapor barrier.

A general rule of thumb for deciding on a perforated or non-perforated radiant barrier:

• If the radiant barrier is to be installed in a closed wall cavity nearest the living space (such as a side wall or cathedral ceiling), a solid radiant barrier should be used.

• If the radiant barrier is to be installed in an attic, we recommend a perforated radiant barrier.

For more information, please see perforated vs. solid and our installation instructions for specific installation methods.

RadiantGUARD® Ultima-NXTgen 1,000 sf roll is available in both perforated and solid version.  All other RadiantGUARD® radiant barriers are offered in perforated only.

Some companies claim their radiant barriers are "NASA certified."  Although NASA was the first to embrace and use the radiant barrier and reflective insulation technology, NASA does NOT certify any radiant barrier product or manufacturer.