Reprinted with permission from Safeguard magazine, www.safeguard.co.nz.   This story is abridged from the July/August 2008 edition.

Peter Bateman describes how a plumber’s alert galvanised an Auckland company into action to prevent electrocution risk from underfloor metal insulation.

Auckland-based Henshaw Group managing director Neal Murphy recalls the day in March 2007 when a plumber responded to a note the company had sent out to all staff and contractors.  The note advised of the new Standard NZS 4246:2006 Energy efficiency – Installing insulation in residential buildings, which had appeared at the end of 2006.

The Standard sets down the methods to ensure underfloor insulation is installed safely, particularly when the foil is stapled to the floor and may become electrically live.  The plumber was concerned that his daily work routinely placed him beneath older houses, right up against retro-fitted underfloor insulation.  What guarantee was there that the insulation had been correctly installed, and would not become electrically live due to insulation staples coming into contact with live wires?

Murphy realised he could give no such guarantee and consulted with a respected electrician, who confirmed the situation was serious: while the probability was fairly low, the outcome would almost always be fatal.  He also discovered at least three people had already been electrocuted in New Zealand while dealing with underfloor insulation.

Murphy briefed the company’s health and safety consultant to get a clear policy in place within a week.  Staff and contractors began to identify the many at-risk houses on the company’s books.  It didn’t take long for more than 850 such dwellings to be identified in one area of Auckland alone.  They found that where insulation had not been installed in accordance with the new Standard – the majority of cases – then there was a high probability that the electrical wiring had never been checked or effectively isolated before installation of the foil, and that the wiring could come into contact with the foil at any time.

Also, in most cases there is no signage to alert people to the danger or to certify that the foil has been installed in compliance with the Standard, or that when the power was turned back on that the foil was not electrically live.

Reports came back of many older houses with cracked, frayed or otherwise damaged underfloor wiring and water pipes.  Contractors regularly report underfloor insulation damaged by DIY repairs or rodents, and they receive frequent callouts to repair underfloor pipes and drains following flooding from internal pipes, causing water to flow through the floor onto the foil.

The resulting Henshaw Group company policy is clear.  No employee or contractor is allowed to work on a house with retro-fitted underfloor insulation until it has been checked by an electrician who has confirmed the environment is safe.  If there is any doubt, the electrician will earth the insulation before any work commences.

The company’s initiative won it the leadership category in the New Zealand Workplace Health and Safety Awards in April 2008.