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Posted By Topic: Building Inspectors... aaarggh

Brian W
Jul 10 2012 13:13

Just had a run-in with a over zealous building inspector. Seems that i'm (we're) not allowed to install flush boxes back to back in fire rated walls, despite them being metal boxes with intumeascant pads.

When i asked him to show me where it says that in the building code (NZS3604) he threw his toys out of the cot and claimed that i should know already, and that he was 'compliance' officer and not an advisor, and that if I wanted to question his ruling i would have to buy 3604.

Called him a Muppet and promptly went to see his boss, who, on searching the code couldnt find any reference to the issue, other than acoustic situations, where they need to be on either side of a stud. However, he also refused to overide the inspector, saying that he (the inspector) had made a ruling and it would need to be complied with for the builder to get code compliance.

WTF. Theres nothing in the building code to support it, but the inspector has made a ruling so it has to be complied with...????

In the meantime the builder lowered the flush box (intermediate light switch), resulting in the cable being too short, and it being 200 lower than the other 3 switches in the room. OUTSTANDING !

Anyone else come across this?

Jul 10 2012 15:05

Only time it has been a issue for is in an acoustic wall, like you mentioned.

Jul 10 2012 15:22

The Wiring Rules does cover this in Penetration of fire rated walls.

Brian W
Jul 10 2012 18:46

Sorry Pluto, that doesnt cut it. The only statement that refers to it there is (a),(i), and since the walls are 95mm thick then the nearest 'service opening' is over the required 50 mil, so there is nothing to prevent a back to back in a fire wall.

Jul 10 2012 20:49

Brian, they're right and you're wrong. Let's leave it at that.

Brian W
Jul 10 2012 21:13

Nope, not until someone can show me where its written into the rules. Building Inspectors are at best, little more than 'rent a cops' who believe they're some sort of gods (down here, at least). Problem is that theyre not consistant. Spoke to another inspector today who would have let it go, and couldnt understand where the other guy got his story from. To be taken seriously the have to all be on the same page. (oh wait, this is beginning to sound like our trade)

Jul 11 2012 09:54

I sympathise, Brian.

i too have little faith in either the intelligence or the usefulness of many people holding jobs as building inspectors.
However, given the way the Building Act works, you have little choice: you either tug forelock to these overpaid and under-qualified half-wits or you go to the trouble and expense of standing your ground - and risk making a permanent enemy.

Either way, thank your lucky starts that as people doing energy work we mostly don't need building consent, and we self-certify; and even for the bits we need an inspector we can choose which inspector - and can always find another one if the first one is like your BI.
Remember until 1993 we used to have the same problem: some of the people holding jobs as electrical inspectors were barely fit to have a licence, and simply made up their own rules regardless of what was in the Regs book. And we still have networks trying to impose rules for installations in addition to those of the Regs & Standards.

Seems likely that calling this particular specimen a muppet won't have helped, but since his boss has proved spineless,try to get the BI to tell you exactly what clause of what documenthas been contravened. You want this in writing (so the goalposts don't move each time you prove the buggers wrong); so write a nice, polite, formal letter which should bring a nice, polite, formal reply.

Re (a)(i); the penetration of a fire-rated building element referred to is one which goes right through the wall, as when cables are run in a ceiling space and go in one side and out the other, so a back-to-back flush box would be a slightly different kettle of fish. Look at (b) instead, where flush boxes in fire-rated walls need to have the same fire rating as the wall had before penetration... so you need to know what that required rating (Fire Resistance Rating or FRR) is... could be that your flush boxes with intumescent pad aren't rated high enough. Not all "fire-rated" walls are equal; depends on usage of the spaces either side among other things.

I can't help with what's in current 3604 either, though i do know the 1990 edition does NOT cover this stuff . As you wouldn't expect it to, it being light timber frame construction and NOT the building code. So If your BI is citing 3604, should be easy enough to prove him wrong - a PDF copy will set you back around $200

What I can tell you is that the relevant section of the Building Code is Clause C Fire Safety(free download from DBH or whatever the new superministry is now known as).
And the Acceptable solution does NOT cite NZS 3604 for anything. Also does NOT cite AS/NZS 3000 for anything. It does cite ECP 54 in the section about outbreak of fire.
On a quick read-through i can't see anything covering penetrations; looks like it sets the requirements for FRRs and then it's up to designers & installers to acheive them.

Can't afford any more time looking, over to you.


Jul 11 2012 18:39

Brian W, you should know better than to take on the local council, if it doesn't have a tick box on their clip board - then "You are in the WRONG"! simple really. One solution might be, fill out a COC for the job - that then states that the building wiring is compliant and the local council will have to accept it. inspectors (building or otherwise) cant makeup rules to suit their ego and if challenged have to provide evidence to their stance.

Jul 12 2012 16:38

Actually a CoC won't help in this case.
All a CoC does is certify that the electrical work complies with the Electricity act and the Electricity (Safey) Regulations.
It does NOT certify that the work complies with the Building Act and Building Regulations (also known as NZ Building Code.
Under the NZBC, a CoC must be accepted by the council as signifying compiance with clause G9: Electricity, but that's only one of many clauses in the Code.
In this case, the clause apparently in question is C: Fire Safety. That clause itself has several parts, but the only electrical compliance document cited in it is ECP 54.

I had to spend a bit of time today hunting some other stuff through clause c, and came across C 6.17 and fig 6.9.

6.17 says:
"6.17.1 the effectiveness of fire separations shall be maintained around penetrations, and in gaps between or within building elements, by the use of fire stops.

6.17.2 fire stops shall have a FRR of no less than that requyireed for the fire separation within which they are installed...

6.17.5 Where used around penetrations passing through hollow construction, the firte stop shall protect the penetration over its full length within the firte separation....

6.17.6 Where service outlets such as electrical sockets and switches emerge from a hollow fire separation, the cavity in the separation shall be suitably protected with an approved fire stop material for the full size of the opening (see Fig 6.9)"

So before entering any arguments / discussions on that, would pay to find out the FRR of the wall, and the FRR of the pad in the flush box.

This BI may be a muppet, but then again he may be right. You can do what he wants, or you can try to persuade him your method complies with the Code For persuasion, seems the first step would be to ask - politely - what exactly is the problem as he sees it.

It is possible to beat them, but you have to do your homework (lots of it); and if you go about it the wrong way, even if you win you may have made an enemy.


Jul 12 2012 19:35

Brain, perhaps you might like to correct your original entry to this posting as only half of your story is correct. You have stretched the story out of proportion, stick to the truth


Jul 12 2012 20:10

What I read and interpretted in the Book I was reading earlier,It mentioned 300mm Horizontal and 600mm Vertical Seperation of Cuts in a Fire rated wall,I hazard Builder dropped 200mm to get around this?Im sticking to what I Know and Know well,I also would love to support paticular Highly Trained Inspectors/dedicated experts Financially by getting them onto site prewire stage.Just hamstrung by clients unwilling to pay up front and save a few bucks.I now can see how some questions get asked and answered at great effort.

Eric B
Jul 12 2012 20:14

On your CoC put a note that your work also complies with NZS 3604, if you have your facts correct, and are willing to back it up if there is a fire that may occur, and possibly cause loss of life. Fire, like other none compliant work (such as is possible with the CTV Building in ChCh, where I once worked full time), can cause death.

A BI will probably accept this note on a CoC, as you are taking full responsibility for any potential future problem regarding any possible future fire.


Brian W
Jul 12 2012 20:40

Not overly concerned about the lowered box. Builder only did what he had to get sign off (in his position I would have done same.) My beef is with the inconsistancy in the interpretation of an apparently non-existant rule that caused it to happen in the first place.


Jul 12 2012 22:07

I'd like to hear from "Sir" he knows more than he's letting on, good to see you sorted out those BI Brian by lowering the box.

Brian W
Jul 12 2012 22:21

Not about to piss a builder off by holding up sign off, only an idiot would do that.

Jul 13 2012 00:03

Agree completely: one set of rules, same for everyone. Not individual interpretationsdepending which BI you get or which tLA you're dealing with (or which network you want to connect to). If there's a disagreement, the particular rule alleged to be not complied with needs to be cited.

Jul 17 2012 20:44

and the correct answer is.... what is the fire rating on the pads being installed to flush box.
Firepro ones are tested for back to back installations for a 120 min fire rated wall, this does not apply to acoustic walls.

Jul 17 2012 20:44

and the correct answer is.... what is the fire rating on the pads being installed to flush box.
Firepro ones are tested for back to back installations for a 120 min fire rated wall, this does not apply to acoustic walls.

Apr 11 2016 19:33

This is an old issue but I am sure it has bugged many electricians. That is the BI believing they have knowledge of electrical safety than we. I think I also added the same question earlier this year as another topic, but can’t locate it.
A BI again required Signage where cables entered or left a structure (even when it was already very obvious). He looked at the detailed drawings I had deposited at the main SwBD, and then informed the owners he would not accept this system. Therefore refused to sign off the site, much to the owner anguish.

He refused to answer my telephone calls. Gave only a partially correct email address. Then refused to answer my questions when I tracked down his correct address.

I then informed the TA that their BI had compromised the safety of the site. My reason was that my choosen system made the site much safer for any potential future owner who hadn’t seen the zigzag trenching for the three underground cables. Not one cable was trenched in a straight line.

I also pointed out that AS/NZS 3000 etc shall be an approved method of verification of NZ Building Code, namely G9. It does not give a TA to interpret it any other way, or that they were allowed to develop and implement their own system.

The other point I noted to them was that this BI had informed many home owners on his first inspection, to make sure the Electrician put signage for any cable buried. He seemed paranoid on this issue. By doing this, he was undermining the electrician’s professionalism.

The TA has now said that if an electrician supplies an Energy Certificate that will be fully acceptable to them. No further issue. They hope that their corrected action is fully satisfactory to me.

The previous BI (B) on the above site a week earlier was not concerned about signage. The home owners thought they had everything noted by BI (B) corrected. Not so, as when the paranoid inspector arrived he altered everything, including an existing structure that wasn’t noted on the building consent. A socket outlet that was about 5 threads loose had to be tightened, was another cause for his inspection to fail the site. I had not even entered this structure, as I had no cause to do so.

I am not concerned about any backlash from the TA. In the worst scenario I would accept it as another challenge. As a previous news cameraman I know how the mainstream media operate. They would have a heyday. If the heats gets too hot politicians will always have the law altered. Just look at today’s news about Tax Havens.


Sep 27 2016 11:13

I know this is an old thread, but perhaps this inspector is referencing a proprietary wall lining system that forbids back to back boxes. GIB in particular has this requirement in their fire penetration guide, I've copied some text below from the section on flush boxes:

Suitable for all GIB® Fire Rated Walls with a (120)/120/120 FRR or less.
Flush boxes may be installed into vertical fire separations using fire stop baffles constructed as
illustrated below. The following other conditions apply:
• Back to back flush boxes are not permitted in the same stud cavity.
• Either steel or plastic flush or surface mounted flush boxes may be used.
• Up to two single width flush boxes or one double width flush box is permitted per
stud cavity.
• Wall linings are not fixed to the framing which supports the baffle boards.

Sep 27 2016 11:53

Unlikely, since there is seldom any requirement for fire-rated walls in a single residence.