26 May 2020
Repairing existing or retrofitting foil underfloor insulation in your home is banned due to risks of electrocution.
Foil insulation banned in residential homes
Retrofitting new or repairing existing foil insulation in residential buildings has been banned under Section 26 of the NZ Building Act 2004. In past years, foil insulation was the most common form of underfloor insulation used in homes. It has now been banned due to its risks of electrocution, and bulk insulation is recommended.
DIYers - be careful if repairing or replacing
If you are installing or repairing foil insulation under your home, you need to be extremely careful. There is a serious risk of electrocution if you accidentally pierce a live electrical cable with the fasteners (e.g. staples or nails) that is used to attach the foil to the house structure.
The foil, being metallic, conducts electricity and can become live if it comes into contact with live electrical wiring – potentially enlivening the entire underfloor of your home. Make sure you turn the power supply OFF first and follow the Electrical Code of Practice ECP 55 which provides guidance for managing electrical safety risks of foil insulation.
Foil insulation can be damaged easily, e.g. by wind or cats. Damaged foil, if it is no longer shiny or is torn, will need to be replaced with bulk insulation as you are no longer allowed to repair foil insulation in residential buildings.
To date, there have been five reported deaths in New Zealand caused by electrocution associated with foil insulation in a residential building, as well as one reported non-fatal electric shock.