Plastic Boxes on Commercial Jobs

don_resqcapt19

Moderator
Staff member
Location
Illinois
Then you don't want to be in the electrical business do you? The OP isn't a contractor but instead an inspector, so the credit issue doesn't apply to him, but having been involved in many, many projects that have been value engineered and/or have specs that aren't compatible with each other, I can think of a dozen valid arguments right off the top of my head on how I would fight a request for a credit for plastic boxes. It very much depends on the situation. There is just no valid reason to require metal boxes with NM cable. If you are going cheap, then go cheap. Engineers are subject to the same problems the rest of us are. They have boilerplate specs, and they don't get paid enough to go through every item of a spec and make sure that it is perfect, so they miss things like this when a job is outside their normal spec wheel house. As an estimator it should be picked up an and at least clarified in the bid, but sometimes the estimator is under the same constraint.

It is extremely unlikely that I would give back a credit for this on a job I estimated and ran. I have spent years honing the skill of identifying counter arguments. One of the best ones is that you always pay attention to the little things you do because you know they must be done even though the plans don't indicate it properly. Like when they show hash marks on a plan and the number of wires is wrong. You don't pull the wrong number of wires, you just do it. That becomes very handy when you explain that you didn't install (or price) metal boxes when plastic was in line with the intent of the drawings, you just did it.
A valid reason is just not required for the the engineer to specify metal boxes. If I designed it specifying metal boxes and the EC used plastic boxes, I would not accept any type of credit. I would require the EC to comply with the contract documents.
 

luckylerado

Senior Member
A valid reason is just not required for the the engineer to specify metal boxes. If I designed it specifying metal boxes and the EC used plastic boxes, I would not accept any type of credit. I would require the EC to comply with the contract documents.
Even if plastic was otherwise perfectly acceptable? Would you reject if the question was asked before the first box was hung?
 

69gp

Senior Member
Location
MA
Then you don't want to be in the electrical business do you? The OP isn't a contractor but instead an inspector, so the credit issue doesn't apply to him, but having been involved in many, many projects that have been value engineered and/or have specs that aren't compatible with each other, I can think of a dozen valid arguments right off the top of my head on how I would fight a request for a credit for plastic boxes. It very much depends on the situation. There is just no valid reason to require metal boxes with NM cable. If you are going cheap, then go cheap. Engineers are subject to the same problems the rest of us are. They have boilerplate specs, and they don't get paid enough to go through every item of a spec and make sure that it is perfect, so they miss things like this when a job is outside their normal spec wheel house. As an estimator it should be picked up an and at least clarified in the bid, but sometimes the estimator is under the same constraint.

It is extremely unlikely that I would give back a credit for this on a job I estimated and ran. I have spent years honing the skill of identifying counter arguments. One of the best ones is that you always pay attention to the little things you do because you know they must be done even though the plans don't indicate it properly. Like when they show hash marks on a plan and the number of wires is wrong. You don't pull the wrong number of wires, you just do it. That becomes very handy when you explain that you didn't install (or price) metal boxes when plastic was in line with the intent of the drawings, you just did it.
The OP just states hes an inspector. If he is an inspector or owners rep he has every right to ask for a credit. If I was doing the 3rd party inspection this is what I would do.

The following is only based on what we know about this project.
Ask the contractor why he used plastic boxes when metal boxes were specified. I would require the answer to be in writing. I would then inform the owner as to the situation and the options available to him.

There are 3 options here.
1) Keep the plastic boxes and do nothing.
2) Keep the plastic boxes and ask for a credit.
3) Change all the plastic boxes back to Metal.

My recommendation would be keep the plastic boxes and take a credit. I know you said you can defend not issuing a credit. I would just reply then we want the steel boxes, its in the specs.

I hope you are not the guy that we just did an inspection on where he has all aluminum busing on his switch gear and panel-boards when copper was specified. This goes for all the feeders also where he changed them from copper to aluminum. Hes in a world of crap. He submitted all copper even on the switch-gear. After everything was approved someone (EC we think) changed the package to AL to save himself a good chunk of money. All I do is file a report. I am pretty sure this one is going to court. I will give him credit he did re-size the feeders.

Does it work? yes
Does it meet code? yes
Does it meet what was specified? No
 

Strathead

Senior Member
The OP just states hes an inspector. If he is an inspector or owners rep he has every right to ask for a credit. If I was doing the 3rd party inspection this is what I would do.

The following is only based on what we know about this project.
Ask the contractor why he used plastic boxes when metal boxes were specified. I would require the answer to be in writing. I would then inform the owner as to the situation and the options available to him.

There are 3 options here.
1) Keep the plastic boxes and do nothing.
2) Keep the plastic boxes and ask for a credit.
3) Change all the plastic boxes back to Metal.

My recommendation would be keep the plastic boxes and take a credit. I know you said you can defend not issuing a credit. I would just reply then we want the steel boxes, its in the specs.

I hope you are not the guy that we just did an inspection on where he has all aluminum busing on his switch gear and panel-boards when copper was specified. This goes for all the feeders also where he changed them from copper to aluminum. Hes in a world of crap. He submitted all copper even on the switch-gear. After everything was approved someone (EC we think) changed the package to AL to save himself a good chunk of money. All I do is file a report. I am pretty sure this one is going to court. I will give him credit he did re-size the feeders.

Does it work? yes
Does it meet code? yes
Does it meet what was specified? No
You are operating on premises that are not in evidence. As a city building inspector, he doesn't have a "right to ask for a credit." and unless he is the owner's brother-in-law, and wants to spend his time scrutinizing every piece of paperwork that has been generated on the job before causing trouble he should just do the job he is being paid for, that is enforcing the building codes. Without, all of the transpiring emails, exact wording of proposals and contracts, previous conversations and instructions, etc. You can't possibly know if the metal boxes was a mistake that was overlooked, a legacy from an earlier evolution of a negotiated bid, an understanding between parties, or an attempt by the EC to pull one over on the owner. More times than not on private work, I have been instructed to VE a project, and many times that VE is wiring methods, Conduit to MC, or romex. I am not being paid to scrutinize 300 pages of electrical specs and correct every item. If a spec was written around conduit and they asked for a Romex VE, I would automatically assume that I no longer needed to use one hole straps, with screws, or steel insulated throat connectors, or metal boxes. I would likely put a little sentence in the proposal that states that "appropriate accessories will be utilized." but if I didn't I would expect the GC and owner's rep to know.

I am not and was not advocating ripping off the customer, which changing everything from copper to aluminum would be a good example of. And if the owner truly wanted metal boxes and it was a romex job from the start with metal boxes clearly spec'd out then I am not advocating just violating the spec. What I am saying is that this is unlikely and the bid, submittal and build process that had gotten them to the rough in stage probably has direct or indirect information that contradicts the requirement for metal boxes and most likely the job was priced with plastic.
 

luckylerado

Senior Member
I would....I don't like plastic boxes, but then my spec would not have permitted NM:D.
How would you justify the added expense to the owner should they have the sense to ask in a design meeting? I am all about holding subs to the specs and am generally extremely firm about it but something like this would be hard to defend with the "because I said so" argument.

If NM were compliant and you designed a building for MC or EMT how are you contributing to the project by specifying something more expensive and labor intensive?
 

ADub

Senior Member
Location
Iowa
If NM were compliant and you designed a building for MC or EMT how are you contributing to the project by specifying something more expensive and labor intensive?
That almost sounds like you're insinuating the wiring methods are equal in function and value when they're totally not. Yes nm is a compliant wiring method in some commercial builds but is not even remotely as functional as pipe and wire and I don't think any decent contractor would have difficulty relaying that information.


Sent from my iPhone using Tapatalk
 

jusme123

Senior Member
Location
NY
Just curious if you are the municipal inspector or are you working for the owner / engineer. I only ask this for the following reason.

If you are a municipal inspector are you required to inspect to what the engineer requires or just what the NEC requires for a minimum?


If you are working for the owner as a 3rd party inspector I can see where you have the right to require the metal boxes.


It would be like saying the specs called for all EMT to be used. But the installing contractor decided to change it to romex because its allowed by code. They both meet code if properly installed.


I do a lot of 3rd party inspections and see this done all the time. Contractors cutting corners. When they get caught its always this excuse or that.


The way I explain it is like this.

You go and order a new caddy fully loaded. Cost you $60,000. Dealer say it will be in in 6 weeks. Boom, you get a call car is in. You go to pick it up and its Nissan Versa $13,000. Both have AC, windows that open and it gets you from point A to point B. What would you say?

...the specs are a part of stamped drawings
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Lucky, Don is in Cook County/Chicago. NM is not allowed there.
I am not really in Chicago or Cook County.

Where I am at we can use NM for dwelling units, something that you can't do in Chicago and many of its suburbs. In my area NM or MC is not used for commercial occupancies....it is all EMT.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
That is the point. I don't like Romex either. We generally don't look at jobs that are done in Romex, but when they are, there just isn't a good argument to keep incur the additional expense of metal boxes.
I have never been a fan of plastic boxes....around here many of the homes done with NM use metal boxes, usually 4 square with plaster rings.
 

JFletcher

Senior Member
Location
Williamsburg, VA
Code-wise, the only case I can think of where plastic boxes wouldnt work in place of metal would be in fire rated walls. Metal boxes are good for 2hr rating, plastic are marked with their rating. So using a 1hr rated box in a 2hr wall wouldnt fly (300.21).
 

69gp

Senior Member
Location
MA
As a city building inspector, he doesn't have a "right to ask for a credit."

You need to read what I wrote. I ask the question of who he is inspecting for municipal or 3rd party. It was not answered so we do not know. If inspecting as 3rd party he is well within his rights to require the metal boxes. All I am saying is if the engineer puts it to paper you better follow it. If you deviate from the contract its at your own risk. Just because you use plastic boxes with romex does not mean that's what the engineer wants. If the engineer says he wants the job done in EMT when you could use romex what would you do?

To qualify your bid beforehand is good. If the GC wants to use your bid with plastic boxes that is ok. But when you submit your submitals for the engineers approval and he rejects the plastic boxes then you need to take that up with the GC. And if he says its not his problem its your wallet the money comes out of.

That is why I keep stressing the point to ask for approval before you bid.
 

kwired

Electron manager
Location
NE Nebraska
Code-wise, the only case I can think of where plastic boxes wouldnt work in place of metal would be in fire rated walls. Metal boxes are good for 2hr rating, plastic are marked with their rating. So using a 1hr rated box in a 2hr wall wouldnt fly (300.21).
If I am wrong someone will correct me but I think there are some 2hr plastic boxes, but I am pretty certain there are 2hr fiberglass boxes that are designed to be used with NM cable, in fact most fiberglass boxes probably are 2 hr rated.
 

James L

Senior Member
If I am wrong someone will correct me but I think there are some 2hr plastic boxes, but I am pretty certain there are 2hr fiberglass boxes that are designed to be used with NM cable, in fact most fiberglass boxes probably are 2 hr rated.
Correct about fiber boxes - 2hr

And quite honestly, here in KC a guy looks like an amateur or cheapskate by using plastic boxes.
 
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