The key to effective and efficient radiant barrier is in its proper installation. For this reason, we always recommend using a certified installer. This minimizes risks such as not properly adhering to building and safety codes, and/or not getting the most out of your radiant barrier.
Radiant barrier is easier to install in a new home. However, it can be installed in addition to fiberglass insulation in existing homes. When being installed in a new home, the radiant barrier is draped across the top of the rafters, foil facing down. To be effective, the reflective surface must face an air space. This method minimizes dust accumulation on the reflective surfaces. Dust accumulation on the reflective surface will reduce its reflective capability. This installation of radiant barrier typically happens before the roof sheathing goes on.
In the case of existing homes, the radiant barrier can also be stapled to the bottom of the rafters from the attic access point. A radiant barrier works best when it is perpendicular to the radiant energy striking it. Also, the greater the temperature difference between the sides of the radiant barrier material, the greater the benefit that radiant barrier can offer.
Due to reflective foil’s electrical conductivity, when installing, it is vital to avoid making contact with any bare electrical wiring. It is highly recommended to NOT install radiant barriers directly on top of the attic floor insulation. If installed on top of attic floor insulation, the foil will be susceptible to dust accumulation and may trap moisture in fiber insulation