EcoFoil Perforated Radiant Barrier blocks and reflects up to 97% of radiant heat, sending it back to where it came from (i.e. - outside in the summer, or inside your home in the winter). Our radiant barrier is constructed using a single layer of tear resistant, woven poly sandwiched between two sheets of highly reflective, metalized aluminum. Our metalized aluminum sheets are unique in the radiant barrier industry due to the way they are produced. The 99.9% pure aluminum is vaporized, then vacuum adhered to the woven poly reinforcement layer to provide durability and optimal performance. EcoFoil radiant barriers were also the first in the industry to pass the ASTM E84-2009 fire test - the industry testing standard for flame spread and smoke development. All radiant barriers tested under older versions of the E84 that have not been retested are not Class 1 / Class A products under the new testing criteria. It is important to understand the difference between solid and perforated radiant barriers. EcoFoil's perforated radiant barrier is ideal for attic floor and rafter applications. The perforations allow vapors from your living space to pass through and be carried out your attic via the ventilation system. It may also be used as a house wrap, allowing for maximum breathability and eliminating interior condensation problems.Cellulose or fiberglass insulation alone will merely slow down the transfer of heat. EcoFoil radiant barriers are meant to work WITH your existing insulation to reduce the amount of heat leaving or entering your home - making your living space more comfortable and reducing your overall energy utility costs.