Blown in insulation roughing tips

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frogneck77 said:
...we ran into a couple problems.(1) Wires are nearly impossible to snake after the fact-In bathrooms we typically leave a large loop above the vanity location with no rough in box-This allows the HO to decide on # of sconces and fixture placement based on mirror size/decorations on the finish stage of the project. With this insulaton my method didnt work too well.
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If you look at the instructions for the fixtures, more than half of them require installation to a outlet box mounted to the structure. You should begin requiring specs on the intended fixtures before rough-in, or they can pay for the re-foam and drywall/paint repairs when they decide to make up their minds.

I used to do the same thing before I realized the code violation - 110.3(B) for the luminaire.

(2) The LV rings for all cable/data/phone locations were full of this insulation making the jacks difficult to install without chipping out alot.
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Sure - use normal electrical boxes for the devices instead of open LV rings. You can go for metallic 4 squares and conduit if future expansion is desired.
 
stickboy1375 said:
I'm a firm believer a house needs to breathe by the way.
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I dislike drafty houses. In my area, humidity is about 10% in a driving rain ( ;) ) so mold isn't really an issue for a well crafted house, IMO.
 
frogneck77 said:
(2) The LV rings for all cable/data/phone locations were full of this insulation making the jacks difficult to install without chipping out alot.
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georgestolz said:
Sure - use normal electrical boxes for the devices instead of open LV rings. You can go for metallic 4 squares and conduit if future expansion is desired.
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Wouldn't you have to run a separate ground wire to
the metallic box since it could be energized by a loose
LV wire? PoE is 48V. Not sure about satellite.

Smurf tube to an orange box or a blue plastic 4-square
that accepts conduit and a mudring would seem
easier than a metal box.

Here in earthquake country, there tends to be
so much metal bracing in the top plates that getting
any kind of conduit (usually smurf tube for LV) to
a box in an exterior wall can be near impossible.

I hate this stuff, but I agree that using a larger normal
box may be the best way to go.
 
I always used the hot BB method where I heated a ball bearing at the top of the wall and dropped it down where it melted its way down to the bottom. This works well until you heat the BB too much and it sets the wall on fire. You had better have some water available when this happens and extra BB s because when you pour water on one melting its way down it will stop where the water hits it. If you think I am kidding just wait until you have to wire one of these nightmares.
 
georgestolz said:
Code reference? :)
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Good point. It's very likely my assumption was wrong.

In my tiny mind I was extrapolating from one manufacturer's
instructions to provide ground wire to their "structured
media center" to mean "metal low voltage boxes like
their smc should be get ground wires", which was probably
not a correct inference.

I looked through article 800 and didn't see anything.
I'm still thinking about where else I would look.

Thanks for making me think about it and disabusing
me of the mistaken assumption.
 
rexowner said:
Good point. It's very likely my assumption was wrong.
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I don't take it for granted that I'm right, I just never have and don't recall it ever coming up on the forum. As far as I know, no bonding is required.

Manufacturers specs calling for it are likely just belt-and-suspender moves.
 
Has anyone seen the change in the '05 NEC in regards to AC cables?

320.80 Ampacity.
(A) Thermal Insulation.
Armored cable installed in thermal insulation shall have conductors rated at 90C. The ampacity of cable installed in these applications shall be that of 60C conductors.

I do not see this requirement for MC-Art330, NM- Art 334 or for UF- Art340.
I wonder why this is a requirement for AC cables only???
 
Pierre C Belarge said:
I do not see this requirement for MC-Art330, NM- Art 334 or for UF- Art340.
I wonder why this is a requirement for AC cables only???
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Because MC always had 90 degree conductors. The early type AC was just as bad (or worse) than the old braided romex or K&T. I see it every day. I don't have scientific facts, but it sure looks like the conductors in the old type AC were the same conductors formerly used in open wiring methods. Put two of them in a metal tube that holds in heat, and you have cooked wiring after 50 years. Insulate that same cable, and you're adding insult to injury. I think it's a righteous move.
 
mdshunk said:
Because MC always had 90 degree conductors. The early type AC was just as bad (or worse) than the old braided romex or K&T. I see it every day. I don't have scientific facts, but it sure looks like the conductors in the old type AC were the same conductors formerly used in open wiring methods. Put two of them in a metal tube that holds in heat, and you have cooked wiring after 50 years. Insulate that same cable, and you're adding insult to injury. I think it's a righteous move.
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Marc
The conductors in AC and MC cable are the same conductors. Why is this requirement for AC cable only?

There really is very little difference between AC and MC cables.
 
Pierre C Belarge said:
Marc
The conductors in AC and MC cable are the same conductors. Why is this requirement for AC cable only?
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Yeah, in modern type AC. I'm talking about old type AC. The only way to prevent old type AC from being insulated is to prevent all type AC from being insulated.
 
I see this as a good back-door way to basically require replacement of vintage wiring methods. With the way building codes are written now, it doesn't take too much to trigger modern energy requirements for the structure (or at least the area involved). To meet these requirements, insulating needs done. To properly insulate, vintage wiring methods will need replaced with modern equivalents. That would then trigger much more electrical work than originally planned for, more than likely. From a business standpoint, you can't not be in favor of the change.
 
mdshunk said:
I see this as a good back-door way to basically require replacement of vintage wiring methods. With the way building codes are written now, it doesn't take too much to trigger modern energy requirements for the structure (or at least the area involved). To meet these requirements, insulating needs done. To properly insulate, vintage wiring methods will need replaced with modern equivalents. That would then trigger much more electrical work than originally planned for, more than likely. From a business standpoint, you can't not be in favor of the change.
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A shorter way to say this is: CHA-CHING!!!
 
Speaking of insulation and old wiring......Went on a call to repair a phone jack that I installed a month ago. They had the attic and crawlspace insulated and the guy must have snagged the wire and pulled it loose. Lot's of knob and tube in the house which is over 200 years old. They insulated it anyway.

After seeing what they did to the phone wire I can only imagine the damage they did to the knob and tube.
 
electricmanscott said:
After seeing what they did to the phone wire I can only imagine the damage they did to the knob and tube.
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That reminds me of a job I worked on where they ran the K&T right next to the scuttle hole in the attic. The K&T had the snot beaten out of it from people stepping on it over the years - many bare spots.
 
peter d said:
That reminds me of a job I worked on where they ran the K&T right next to the scuttle hole in the attic. The K&T had the snot beaten out of it from people stepping on it over the years - many bare spots.
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That doesn't sound like wiring. That sounds more like a booby-trap.
 
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