Wet Romex Usable?

Status
Not open for further replies.
M

mkgrady

Senior Member
Location
Massachusetts
When a house gets soaked from a leaking heating system is the NM cable still usable if it got soaked?

The house was built in 1988. I assume type NM cable was used back then.

THe heating system is forced hot water with an antifreexe mix in the pipes.

The boiler was on the top floor and developed a leak. All the ceilings and most of the walls were ruined and are being demoed in this four story house.

The home owner recently moved out. The house was unoccupied and was being spruced up with paint and other cosmetic repairs before the leak so it could be rented to a tenant.

Does the place need to be rewired? Of course the owner will look to his insurance company to pay.

I'm going to look at the place tomorrow and wondered if NM cable could not be used in a wet location what would make it OK to use it after it gets wet?
 
the insulation is plastic and the sheathing is plastic so I vote no. A little paper might have gotten damp but it will dry out.
 
The Iceman said:
Good question but my opinion would be 334.12(B)(4). If it was exposed to excessive moisture then no good.
Click to expand...

That section lists where NM can not be used (where exposed or subject to excessive moisture or dampness). The cable was permitted to be used inside the house (of course). I don't know if the leap can be made that once it is exposed it must be replaced, at least not by reading that section alone.
 
satcom said:
See what the megger testing shows.
Click to expand...

That sounds like alot of work. I'd rather skip that step if there is some standard that says replace the NM if it gets soaked with water and antifreeze. If the standard is to megger each cable then at least I can justify the expense to the customer.
 
celtic said:
Anyone see this;
Guidelines for Handling Water Damaged Electrical Equipment


(it's a pdf file)


From: http://www.nema.org/stds/water-damaged.cfm
Click to expand...

Well that certainly says replace NM cable if it gets wet. Also goes for circuit breakers, GFCI's and all devices, and if I contact the manufacturer I can ask how to recondition the panel.

This soaked house situation must happen alot in the home owner insurance business. Anybody ever get any resistance from the insurance companies on paying to replace all the above?
 
220/221 said:
the insulation is plastic and the sheathing is plastic so I vote no. A little paper might have gotten damp but it will dry out.
Click to expand...

My first thought was to agree, then I thought about how the water reacts to the NM cable.

I may be wrong but it seems the water can't go through the jacket to wet the inner insulation, and if that is true, if water runs down the inside of a NM jacket it will remain there soaking the conductor insulation with no way to get out. Will this breaks down the insulation over time? Could it be that even meggering the cables now would not show a problem? I'm just guessing here.
 
a little bit of water isn't going to cause any damage.

Water eveporates. It WILL dry out.

How many times have you pulled out UG wiring to find that the conduit is obviously filled with water (from condensation I presume) an dprobably has been for 20 years?
 
mkgrady said:
That section lists where NM can not be used (where exposed or subject to excessive moisture or dampness). The cable was permitted to be used inside the house (of course). I don't know if the leap can be made that once it is exposed it must be replaced, at least not by reading that section alone.
Click to expand...

All Im saying is thier is a reason why 314.12(B)(4) is in the NEC. NM should not be used in wet locations. If the house has a major flood and the NM gets wet then its in a wet location. Would you reuse all the rcpts. and switches?When you run romex in a house its a good idea to start it after roof is on so it doesnt get wet. Its late Ill sleep on this one.:grin:
 
The concern, it seems to me, is for the integrity of the equipment grounding conductor. If the cable has admitted water, then the paper cover will have the potential of corroding the egc and eventually losing the ground-fault current path so necessary to protect the building and its' occupants from the hazards associated with a fault unable to clear. :smile:
 
Just from the liability standpoint I'd say replace it unless you can get a document from an engineer saying that the water/antifreeze/dirt/etc. that got washed into that NM won't cause insulation damage.
 
whillis said:
Just from the liability standpoint I'd say replace it unless you can get a document from an engineer saying that the water/antifreeze/dirt/etc. that got washed into that NM won't cause insulation damage.
Click to expand...

It was not just water, the original poster stated so.
If all the ceilings and walls are coming down, I as an inspector will make it easy, based on the documents that Celtic posted.
Megger the conductors and show me the documented results to be put in a file for that job.
 
220/221 said:
a little bit of water isn't going to cause any damage. Water eveporates. It WILL dry out.
Click to expand...
Absolutely. Just overload each circuit for a couple of hours. :grin:

How many times have you pulled out UG wiring to find that the conduit is obviously filled with water (from condensation I presume) an dprobably has been for 20 years?
Click to expand...
You mean wire rated for use in a wet location?
 
Have any of you guys ever actually wired a house? Thousands of houses every year get framed and rough wired and then get rained on for days at a time.

Thousands of electricians keep Romex in the bed of their trucks exposed to the elements for weeks before being installed in someone's house.

I've installed Romex that was actually submerged underwater and never experienced any problems.

There are two kinds of electricians on this forum: Theoretical Electricians who have little real world experience wiring structures and Practical Electricians who've been there and done that.

Any Practical Electrician will tell you that water does not destroy NM cable, the Theoreticians will believe otherwise.
 
If the cable has admitted water, then the paper cover will have the potential of corroding the egc and eventually losing the ground-fault current path
Click to expand...

I was assuming that it was COPPER wire. If water corrodes your copper wire, the issue would be with your water.

Like the FA pointed out, romex often gets wet when it is installed before the roof is dryed in.
 
I'm kinda with Fire Alarm on this one. Besides that fact that many homes are wired during the rainy season and before the roofer shows up and also the idea that I've got five service trucks out there with open beds and rolls of romex; we do a lot of work for insurance companies who are repairing houses damaged by broken water pipes (very common here). Only once have I been asked to megger the branch wiring. And they never will pay for a rewire. We remove all light fixtures and devices and replace after drywall. We replace all circuit breakers that have been soaked, and that's about all the insurance company will usually pay for.

I don't know about the antifreeze though.
 
most thhn these days is also thwn, may be the case here. but either way, i would not replace NM that got wet on the outside, even if a bit trickled in through the boxes, it will dry out.
 
we do flood damage work and we always replace devices but seldom do we replace romex the problem with water damage is not the water but what the water leaves behind when it evaporates
 
Status
Not open for further replies.
Top