Plastic vs. Metal Boxes

[JOHNEO99]

Hi

Im doing a job in an area that is mostly done using emt and not romex. This is a residential job and the builder has been trying to cut costs to induce sales. The local building department has just started to allow romex in their village and we are changing from pipe to romex. The village allows plastic boxes but for some reason (I'm not sure what it is) the builder wants me to use the same metal boxes that we use when piping these homes.

I believe they are worried about the integrity/long term durability of the plastic boxes vs. the metal. I disagree that the plastic boxes are a risk to this factor and I really want to use the plastic boxes for obvious reasons.

Can some of you people give me some reasons as to why plastic is as good or better than metal when installing romex?

I think the opinion of this community should help me with my agenda here.

Thanks

John

[peter d]

I'd say the fact that billions of them have been installed and in use is good enough for me.

[BryanMD]

I believe they are worried about the integrity/long term durability of the plastic boxes vs. the metal.

why stop there?
dig out your grandfathers solder pot and do away with wirenuts too ;)

[Cavie]

Maybe someone here will post a pic of a mega$$$$ million house being roughed in romex with plastic boxes for you to show how it's done.

[Power Tech]

The plastic boxes have a 1 hour fire rating.

They are deeper.

Less cost.

Less work.

[ceb58]

The plastic boxes have a 1 hour fire rating.

They are deeper.

Less cost.

Less work.

All of the above.
With the box in a wall covered with Sheetrock/ paneling they are not subject to damage. Try this with your GC buy a carlon plastic box, nail it to a stud just like it is supposed to be. Then give the GC a hammer and tell him to beat the box off the stud. He will after several swings break the box off but then ask him if he thinks that box will see that kind of abuse inside of the wall.

[ultramegabob]

Price a job both ways and then let them choose, use whatever they ask for and just price accordingly.....

[dejeud]

This has to be the easiest answer.
Three words:
Resistance to change.
Could be also 2 words if you don't think "to" should count as a word, but anyway.
Humans are always resistant to change, or afraid of change. In either case, there's something about humans that don't want to change, be it food, clothes, or Aluminium wire.
Speaking of AL, I think it's the best example to people resistance to change.
Look at AL wire, now I know the old AL used to be too soft therefore the connection got loose with time and so on and so forth, BUT:
1: In my 7 years doing service I found just as many AL connections being cooked as I found Copper. And this is based on probably MORE AL connections than Copper.
2: The new AL is not as soft as the old AL, so even the need of "lollipops" has been eliminated.

Now consider the advantages of AL wire:
1: It's the second largest resource on earth after Iron (or 3rd if you consider Oxygen a resource)
2: AL has lower ampacity by volume, but much higher by weight. Guess what, you buy the wire basically by weight, therefore the price doesn't even begin to compare.
3: The difference of ampacity between Copper and AL are almost insignificant, most of the times you'd only have to go one size larger to match ampacity of copper.
4: Even going a size larger, doesn't always mean you have to increase conduit size. Check the size of 700XHHW AL VS 600 copper and you'll be surprised to learn that the AL is almost same size. Now look at weight per 1000' Copper is almost double than the one size up AL, now figure $3/lbs for 2000' of copper VS $1/lbs for 1000 lbs of AL. $ 6000 VS $ $1000. No brainer? right? guess not.
5: Because the weight AL is a hell ov a lot easier to pull than copper.

So why isn't the whole world sold on AL? (least for feeder wires?). If it's not resistance to change I don't know what it is.


Hi

Im doing a job in an area that is mostly done using emt and not romex. This is a residential job and the builder has been trying to cut costs to induce sales. The local building department has just started to allow romex in their village and we are changing from pipe to romex. The village allows plastic boxes but for some reason (I'm not sure what it is) the builder wants me to use the same metal boxes that we use when piping these homes.

I believe they are worried about the integrity/long term durability of the plastic boxes vs. the metal. I disagree that the plastic boxes are a risk to this factor and I really want to use the plastic boxes for obvious reasons.

Can some of you people give me some reasons as to why plastic is as good or better than metal when installing romex?

I think the opinion of this community should help me with my agenda here.

Thanks

John

[macmikeman]

I bet that same GC puts in Pergo floors. I bet he uses Tyvek instead of roofing paper to moisture seal in the house. I bet he uses a nail gun cause it is faster. I bet he doesn't even own a handsaw. I bet he cools his house in summer with air conditioning, not meerly opening up windows. I bet he doesn't fill his tank with leaded gasoline. I bet he was the last one to try all those things.....

[infinity]

If they're willing to pay for metal boxes why not just use them?

[AV ELECTRIC]

You dont have to bond the box as you would with metal. plastic is non conductive cant be electrified. Does not corrode. Ive seen moister get to metal boxes and they decay over time.

[BryanMD]

Maybe someone here will post a pic of a mega$$$$ million house being roughed in romex with plastic boxes for you to show how it's done.

like this one?

[LarryFine]

Can some of you people give me some reasons as to why plastic is as good or better than metal when installing romex?
If he's that closed-minded about it, he'll ignore all the reasoning in the world.

I suggest offering him the cost for using each type of box, and let him decide.

If he's willing to pay more for you to continue use of the metal boxes, so be it.

[Power Tech]

In some situations (back to back switch in wood) I use metal so the switch is not too far from the door. Customer ends up with a dirty mark on the wall.

I would accommodate too. Be generous with the deep boxes.

I would use the plastic if there is a fire envelope. You can pad the metal boxes with clay instead. May be a few cents more.;)

[mkgrady]

Can some of you people give me some reasons as to why plastic is as good or better than metal when installing romex?

What is his reason why metal is better? I doubt he has a valid one.

If you use plastic you will save way more than the price difference between box types.

[kbsparky]

Plastic boxes don't rust. :grin:

They can't short out on a bare piece of wire, or loose terminal.

You won't have to buy any green screws, either.

We did a job once where we had to remove all the rusted out metal boxes, and reinstall plastic ones. 20 years later, those plastic boxes are still in use.

[marti smith]

You could always ask him if he'd like to install one of each himself and see what he thinks (you don't give him a drill, just a flathead- oh, even better, an offset flathead) and be sure to give him two 2-screw romex connectors and a grounding pigtail. That should set him straight.

[celtic]

Here is a similar thread from July '09...raging on for 3 pages here:
Plastic vs. metal j-box? (http://forums.mikeholt.com/showthread.php?t=116198&highlight=plastic)

[electricmanscott]

You won't have to buy any green screws, either.


You wouldn't have to buy any with metal boxes either. ;) :D

[220/221]

Simple.

Plastic boxes are safer in NM applications because they are non conductive just like the sheath on the cable. They were engineered and designed decades ago especically for use with NM.


The fact that they are easier and less expensive is a bonus brought on by supply and demand.

[readydave8]

I've heard that its better to use a metal box with dimmers as they dissapate heat better than plastic--is this true?

[active1]

You dont have to bond the box as you would with metal. plastic is non conductive cant be electrified. Does not corrode. Ive seen moister get to metal boxes and they decay over time.

I seen 100 year old black metal boxes look good as new. What is the oldest plastic boxes out there still working? I wonder if the plastic gets brittal over time making it more prone to cracking.

While there are some locations not for metal boxes. Inside a resi interior wall seems like moisture would not be an issue. If it is enough to rot out a galvanized box then maybe it's time to gut and redo the place.

Metal boxes and EMT are the norm in Northern IL. But if your going with NM you may as well use the plastic boxes.

[active1]

[QUOTE=kbsparky;1107381} :grin:

They can't short out on a bare piece of wire, or loose terminal.

[/QUOTE]

That's a good selling point for the customer.

[mcelweec@gmail.com]

personally my only pet peeve with plastic is the inexperienced drywaller with the dreaded rotozip.

[kbsparky]

I've heard that its better to use a metal box with dimmers as they dissapate heat better than plastic--is this true?
I would think that using a metal cover plate would be more effective.

[480sparky]

I'd say the fact that billions of them have been installed and in use is good enough for me.

I'd say the fact that billions of them have been installed and have had no significant problems simply because they're plastic is good enough for me.

[Pierre C Belarge]

You wouldn't have to buy any with metal boxes either. ;) :D



Scott, I knew if anyone answer this way, it would be you. ;):D
Wait...are green screws listed?:roll::D

[Pierre C Belarge]

I forgot to add.
Some have an issue with the threaded hole for the device screw. What some do is use metallic raised roughing covers on 1900 boxes to alleviate this issue.

I used to shun plastic boxes as a contractor, but today, the market is so tough and the quality of plastic boxes is better, that I would use plastic myself. It keeps the weight in the truck down too. :D

[growler]

the builder wants me to use the same metal boxes that we use when piping these homes.

Can some of you people give me some reasons as to why plastic is as good or better than metal when installing romex?

The plasic are faster and thus cheaper but they do look a little on the lite weight side.

Try showing him the Carlon Super Blue hardshell boxes. They look and feel a bit more substantial than the average plastic box.

[Pierre C Belarge]

I forgot to add.
Some have an issue with the threaded hole for the device screw. What some do is use metallic raised roughing covers on 1900 boxes to alleviate this issue.

I used to shun plastic boxes as a contractor, but today, the market is so tough and the quality of plastic boxes is better, that I would use plastic myself. It keeps the weight in the truck down too. :D


I want to restate this, if you all do not mind.

I used to shun plastic boxes in the past. Today the market is so tough and the quality of plastic boxes is better than in the past (for me the past is 20 years ago). I would use plastic boxes is certain installations today, and carrying them in the truck does keep the weight down too.

[LarryFine]

I want to restate this, if you all do not mind.No problem; go right ahead. :)

I used to shun plastic boxes in the past. Today the market is so tough and the quality of plastic boxes is better than in the past (for me the past is 20 years ago). I would use plastic boxes is certain installations today, and carrying them in the truck does keep the weight down too.Thanks. I enjoyed that. :grin:

[pjmurph2002]

John - what town in N. Illinois are you working in? I am also in N. Illinois.

Thanks

[benaround]

He wants metal boxes because after that romex burns up, the boxes will be all set to

use EMT !!

[JOHNEO99]

John - what town in N. Illinois are you working in? I am also in N. Illinois.

Thanks

Mundelien, IL

[JOHNEO99]

Thanks for the replies guys.

I really hope he has a change of heart. Hes just doing his job and in these times everybody is cautious.

This Thread has to be my best here. Maybe a repost but I enjoyed it.

[VoltageHz]

like this one?

That's nice work, I like how they transitioned off that beam down into the panel with the sweeps.

Those cables running horizontal above the panels, what are they fastened to?

[mcclary's electrical]

He wants metal boxes because after that romex burns up, the boxes will be all set to

use EMT !!

Are you joking?

[pjmurph2002]

Hello John-

I was shocked to here that Mundelin is allowing Romex. I checked the towns website today and found that they are operating on the 99' NEC. The village ammendments to the NEC DO NOT ALLOW ROMEX.

Check with the village inspector directly to be sure Romex is allowed. Please let me know what you are told.

Thanks

[LarryFine]

Those cables running horizontal above the panels, what are they fastened to?Pairs of vertical 2x2's or 2x3's flanking the vertical NM's rising out of each panel.

[active1]

He wants metal boxes because after that romex burns up, the boxes will be all set to

use EMT !!

This thread is too funny.


Or they want metal boxes because the village does't allow NM cable. After the inspector makes you rip out the romex your metal boxes will be there for the EMT. Sounds like good advice that will save you time. Make sure you drill your cable holes straight & big enough for when it gets changed to EMT.

Says here they are on 2008 NEC:
http://docs.google.com/gview?a=v&q=cache%3AOSpbvRxw6noJ%3Awww.mundelein.org%2Fforms %2Fcd%2FBuilding_code_handout.pdf+mundelein+buildi ng+code+ammendments&hl=en&gl=us&sig=AFQjCNER7rskD8AtAn7gbU4Pp4Z_A2nBZw&pli=1

From their ammendments:
All alterations of electrical wiring systems must be made in a raceway of rigid conduit, intermediate conduit, or electrical metallic tubing.

(t) Amendments to Article 336--Nonmetallic-Sheathed Cable: Types NM, NMC, NMS. Delete this section in its entirety.

Most other wiering methods are deleted also.

Not to sound rude but when bidding a project you really should spend a few minuits and find the local code requirements. It's not a bad idea to review them again before starting work. Many places have plenty of got-ya's that only apply to their location.

[don_resqcapt19]

This thread is too funny.


Or they want metal boxes because the village does't allow NM cable. After the inspector makes you rip out the romex your metal boxes will be there for the EMT. Sounds like good advice that will save you time. Make sure you drill your cable holes straight & big enough for when it gets changed to EMT.


I am reasonably sure that the village in question has made a recent change in their code to allow NM and that was alluded to in the first post of this thread.

[Article 90.1]

I just bid a remodel job where the specs. called for NM with metal boxes. I wasn't happy with my bid price, though so I ran the job again using assemblies consisting of NM and plastic boxes. I was really surprised at the difference in labor units and material cost between plastic and metal. the metal boxes made my project cost considerably more than using plastic boxes.

Another option that I like to us is the Allied Moulded boxes, I think a lot of guys hate them, but I have always liked them. They are more expensive than blue boxes, but can make your company stand out above the competition if you sell it as a better quality installation, which is probably what the builder is looking for anyway.

[peter d]

Another option that I like to us is the Allied Moulded boxes, I think a lot of guys hate them, but I have always liked them. They are more expensive than blue boxes, but can make your company stand out above the competition if you sell it as a better quality installation, which is probably what the builder is looking for anyway.


If it comes down to a "hard shell" box over PVC, I prefer the brown T&B-Union bakelite boxes over the Allied. They don't break as easily and don't strip out as easily either. But, Allied is way more common and popular than Union so that's why you don't see them much, despite the fact that I think they are far superior to Allied. So you can count me as one of those guys who hates Allied boxes. :grin:

[LarryFine]

I don't like any box that explodes when you miss a nail. I have never had a problem with the el-cheapo blue Carlons.

[peter d]

I don't like any box that explodes when you miss a nail. I have never had a problem with the el-cheapo blue Carlons.

You can't swing the hammer like the Green Giant, Larry. :grin:

[hurk27]

I don't like any box that explodes when you miss a nail. I have never had a problem with the el-cheapo blue Carlons.

Especially if your fingers are in it holding it to the stud:mad:

You can't swing the hammer like the Green Giant, Larry. :grin:

I would think it was because he was swinging it like the green giant, then he turned in to the black and blue giant, well at least the fingers did.:D

[LarryFine]

You can't swing the hammer like the Green Giant, Larry. :grin:Sure I can! ;) Ho, ho, ho!

[Power Tech]

I don't like any box that explodes when you miss a nail. I have never had a problem with the el-cheapo blue Carlons.

I do....When I'm doing demo.;)

[petersonra]

the builder wants me to use the same metal boxes that we use when piping these homes.

The customer is always right.

I would point out to him that it does add a certain amount of cost per box to do it this way. He might be surprised to find out just how much and may decide he really does not need metal boxes after all.