Foil backed insulation (also known as foil faced insulation) has become increasingly popular as an exterior insulation and floor insulation material because of its added R-value and decreased thickness. The ease of installation and noticeable energy savings make this material a DIYer’s dream. However, there are some substantial issues that have to be taken into consideration when using a material like foil backed insulation as improper installation can lead to serious injury or even death.
What is foil backed insulation?
Foil backed insulation is any insulation material that has a reflective foil backed backing on it. The foil is a thin film aluminum coating that is attached to either fiberglass batts or polyurethane or expanded polystyrene foam board insulation. The aluminum foil facing gives the insulation an added vapor barrier, extra fire retardancy, and resilience to moisture and mildew. It also reflects heat which is very important in warm weather climates and in homes that use interior insulation as a heat loss reduction method in certain areas.
While foil backed insulation is a great material for many practical uses, the aluminum foil facing is metal. This creates a large and expansive surface for stray voltage to electrically charge, possibly to extreme level. This can occur if a nail of staple that is holding the insulation into place accidentally pierces through or into a live wire energizing anything conductive the staple/nail touches. In this case, it is an entire ceiling, wall, or floor. This becomes doubly dangerous with in-floor water heating because now you introduce another component that has feeds many of the area of a home.
All of a sudden, you have an enormous potential for an electrical fatality or, at the very least, the shock of a life time. This very problem has become an extremely controversial issue in Australia where the launch of Australia’s Insulation Program has been temporarily ceased due to four confirmed deaths that are a direct result of the energizing of foil backed insulation. This is a common material used in Australia and has been heavily touted by the Australian government as part of the launch of this program. Tens of thousands of homes that have already been retrofitted with foil backed insulation are currently being tested to avoid other issues and fatalities.
Safety precautions to take
The greatest safety precaution to take when applying foil backed insulation is to make sure that you mark where all wires and electrical connection are before nailing, screwing, or stapling the foil backed insulation in place. This will, in all likely hood, prevent most issues that can occur with foil backed insulation.
During the insulation process, consistently test the insulation face for stray voltage. This will help you pinpoint where the voltage is coming from because you can test every sheet. Who knows? It could also save you and your family from a disaster that could have happened if you never would have added the insulation in the first place.
Foil backed insulation is a great product and this article is in no way stating that it should not be used. It is simply important to note that there have been issues and that precautions taken during the installation process should be taken to ensure the safety of everyone in the home