Energized foil faced insulation

[Michael Thomas]

I have a boilerplate comment in my reports regarding potential electrical hazards when I encounter foil-faced insulation; I report as an FYI item in the absence of wiring defects, and is a safety issue if I observe any defects which might make it more likely a foil vapor retarder could become energized.

In the future I'm going to be linking it to a PDF I've made of this report:

"The Australian government has ordered a huge safety audit of every home that was fitted with foil insulation as part of a nationwide energy-saving plan.The insulation programme was suspended after it was linked to a number of electrocution deaths.

Tens of thousands of homes will now have to be checked.

Improperly installed foil insulation can conduct electricity from mains cables, effectively making the entire roof cavity live.

The national insulation programme was a key plank of the Rudd government's environmental strategy, and offered rebates to householders who wanted to conserve energy.

But the metallic foil used in older houses has already killed four electricians who were installing it, the most recent incident coming last week when a 25-year-old contractor was electrocuted in the roof of a home in far north Queensland.

It is believed the metallic foil came into contact with electricity cables, thus making the roof cavity live..."

BBC News - Australia to check safety of 'live' foil insulation (http://news.bbc.co.uk/2/hi/asia-pacific/8507538.stm)

In addition I'm going to make an extra effort to remember to always pull out the proximity tester when I encounter foil faced insulation.

[A.D. Miller]

Though I do not doubt the veracity of this information, it is reminiscent of an HI I know who checks all aluminum windows and doors for stray voltage, which is usually only a problem in dairy operations, etc.

[Bruce Breedlove]

But the metallic foil used in older houses has already killed four electricians who were installing it, the most recent incident coming last week when a 25-year-old contractor was electrocuted in the roof of a home in far north Queensland.


Why are electricians installing insulation?

[A.D. Miller]

Why are electricians installing insulation?

BB: Not intelligent enough to become HIs, as is illustrated by many of their postings on this forum.:D

[ken horak]

BB: Not intelligent enough to become HIs, as is illustrated by many of their postings on this forum.:D

maybe they have more self respect for themselves,then to lower their standards to the level of HI:D ;) :p :p

[A.D. Miller]

maybe they have more self respect for themselves,then to lower their standards to the level of HI:D ;) :p :p

KH: Yessir.

[Stacey Van Houtan]

I am going to write up all homes with plumbing becuase the pipes could leak and cause mold

[Rich Goeken]

My first reaction to this was "If the electrical work was installed to code---How are they coming in contact with power as they install the foil?" My second reaction was "If during the pre-installation inspection of the job site, it appeared that the electrical work was not up to code, or tests indication energization----why did they proceed? Why didn't they either make corrections or refuse to work in an unsafe situation?" And, as already asked, why are they installing the insulating foil anyway?

[Peter Dohm]

I a Realtor and not an HI or an electrician; but I really wonder if some or all of the accidents could have been in very old homes that were wired with knob and tube.

I know that sounds almost too stupid to believe; but I've seen some stupid things and heard of worse...

[Michael Thomas]

I am going to write up all homes with plumbing because the pipes could leak and cause mold

Most people are aware that pipes can leak, and many of those that leaking pipes can lead to mold.

When I've had occasion to make the point, most people were unaware until I did that the loose wiring protruding from the electrical box had the potential to energize foil insulation.

[Michael Thomas]

I a Realtor and not an HI or an electrician; but I really wonder if some or all of the accidents could have been in very old homes that were wired with knob and tube.

I know that sounds almost too stupid to believe; but I've seen some stupid things and heard of worse...

Welcome to the board - as a real estate agent you have the potential enormous amount about the the homes you sell by participating in the discussion here, but I hope you have your flameproof underwear on, as you will find that real estate agents are not popular with some posters here.

To answer your question, one of the first things you will learn here is that there is nothing "almost too stupid to believe", the reason it is impossible to idiot proof the ownership and operation of homes is because the opposition keeps building better idiots!

Probably some of these fatalities resulted from carelessness either on the part of the insulation installers, the people who built the house, the people who improved and maintained it, or some combination of these, and some of these may have been related to K&T or other antediluvian wiring methods.

But the combination of foil insulation and older house, especially if there is blown in insulation or other materials obscuring the view of wiring defects below it, truly is a booby-trapped of sorts.

I was quite impressed to learn that there had been four fatal incidents (and who knows how many nonfatal events and near-events that went unreported and perhaps unrecognized) in only a few thousand installations. That's a very high fatal accident rate for any kind of construction or remodeling activity, and IMO ought to be wake-up call to anyone who supposes that this is some sort of exaggerated or unreasonable concern; AFAIC it's a pretty good argument for de-energizing attic circuits before doing any kind of maintenance or other work that brings you in contact with foil-faced attic insulation, and a very strong argument for taking 10 or 15 seconds required to test such surfaces with a non-contact detector prior to inspecting such an attic.

[Stacey Van Houtan]

Foil insulation is a very good product, it provides the best vapor barrier and in addition it will help with ir heat gain, I would assume that Ir was the reason it was chosen. Since this is a huge desert area. Drywall with a foil back has been used as well as plywood, Its not the product. this is still used in commerical and i am seeing more in my area in residential. It was used as a under the floor joist vapor barrier in many crawl spaces in the past. I think the down under electrons goe counter clock wise causing havock

[Chris Fahey]

THE FOIL INSULATION HAD BEEN LAYED ACCROSS THE BOTTOM CHORDS OF THE TRUSSES AND FASTENED DOWN WITH METAL STAPLES AND IN SOME CASES THROUGH A CABLE MAKING THE WHOLE AREA LIVE.

[Jerry Peck]

THE FOIL INSULATION HAD BEEN LAYED ACCROSS THE BOTTOM CHORDS OF THE TRUSSES AND FASTENED DOWN WITH METAL STAPLES AND IN SOME CASES THROUGH A CABLE MAKING THE WHOLE AREA LIVE.

Precisely what I was going to point out.

Only slightly differently: We have all experienced, or at least heard about, nails penetrating cables and causing all kinds of problems, so all we need to add to that is 'the nail going through foil insulation' and then into the wire ... and what was described happens, and it is not even "stupid people" doing anything, it is simply a fact of life in construction that things can, do, and will "go wrong".

It is that same reason that metal studs are now grounded. An inspector friend of mine found energized metal studs, in tracing it down we found a drywall screw had hit an NM cable which was not properly clamped back the required 1-1/4". The NM cable was probably installed like the majority of NM cables are installed, close enough to being okay so as not to raise a flag with the inspector, but also "close enough" to allow the drywall screw to hit it and energize the entire interior framing made with metal studs.

[bob smit]

I don't know why, but I have observed numerous instances where cut off cables and especially open splices were left flopping and laying around in attics; more so than any other location.
Perhaps out of site out of mind??

I do question the possibility for an attic to be full of energized foil, yet nothing to act as a return path back to the panel, thereby tripping the overcurrent device. If there isn't a viable return path to operate Breaker/fuse, where did all these electricians find them, and how did these return paths suddenly become sufficient for more than the standard shock we've all had more often than requested. The electricians, would of course, had to be in contact with both at the same time.
Just a thought.
Bob Smit, County EI

[Mike Schulz]

Foil face, Metal roofs, Metal siding, Metal lath, does everyone write it up to be bonded ?

[bob smit]

Per NEC 2008: Unless steel structure is effectively grounded, it does not need to be used as one of the 'grounding electrodes'.
As far as bonding requirements; only those items deemed as 'likely to become energized' require bonding. This is an AHJ call.
Most do not require bonding of those mentioned.
I personally require bonding of metal sided structures such as a pole barn due to the exposure of wiring and all the metal to occupants.
Bob Smit, County EI