Flood waters & romex

[redikillowatt]

My homestead got some water in the house in recent TX storm. I've run across several people citing articles that if standard NM-B residential romex is under water - at all, for any time, the paper wrapping can get wet & "eventually ruin, cause corrosion / problems, etc., with conductors, so wiring should be replaced.
However, I can't find appropriate code for what *actually* needs to be tested, how - or deciding the length to replace.

Start slicing test sections of wire open & see how far the paper wrapping wetness extends, if at all?
Then what - cut a few inches above the paper wetness, set a box inside the wall & run new wire to the outlet boxes?

The lower drywall sections & insulation are already removed. At the peak, maybe 8" water in the house - based on 8" x 16" cinder blocks on end, elevating furniture were only wet less than 1/2 their length.
Morning after water receded, I looked in some std height wall outlets. No sign of moisture, silt or flood water debris in the boxes.
While drywall was wet & a little water left on floors. So, I'm not at all sure the water level got to most outlets. A couple of outlets near the floor - probably got water.

No salt or brackish water involved. Very little if any silt, mud left on floors - surprisingly clean flood water.

What does NEC or TX say about checking for wet paper wrapping and recommendations how far above the wetness to replace wiring?

I'd be really surprised if fresh water, this clean would "destroy" the copper conductors. But maybe...
Thanks.

 

[ActionDave]

If it were my house I would not replace any romex just because it got wet. Devices, breakers and equipment, yes.

That stuff about the paper getting wet is busy body, hand wringing, ninnies getting all up in people's business over something they don't like, with zero evidence of a problem.

That said, if it's required by insurance or code enforcement then I would do it at your house.

 

[jumper]

Useful link on water damage and electrical equipment:

https://www.nema.org/Standards/Pages/Evaluating-Water-Damaged-Electrical-Equipment.aspx

 

[redikillowatt]

Thanks guys. I'm quite experienced at residential wiring & always followed code. I've lost my electrician friends/ contacts, for odd, tough questions.
Yes, it seems odd, only fresh water - pretty clean at that, would eventually ruin paper wrapped conductors. Salt water or from lakes by a nuclear plant MELT down, I could see a problem.

Anyone know if any Official electric code - from anywhere - discusses this issue? If no elect.code discusses it, why would the UL write articles? Payola from wire mfg's?

Someone linked me an article from Underwriter's Laboratory - UL, discussing the wet paper issue. UL but didn't hint at specific actions. Just "replace wiring if the paper got wet."
Other example articles (below). AFAIK, none mention a testing procedure for romex, where to cut wire, etc. None are national code or TX.

I'll try to D/L the paper that jumper linked.
I can search an NEC copy on disk. Does anyone have an idea what NEC section this might be under (if at all). I'd appreciate the info.

In worst case, does any code forbid attaching boxes with lids - to studs - to splice on new romex sections, inside a closed stud cavity w/ drywall on both sides of a wall?
The only reason I can think of it not being allowed, is if code requires all junctions / connection boxes - even w/ lids - to be accessible w/o cutting walls open.

http://www.southwire.com/support/Gui...reAndCable.htm

http://www.dli.mn.gov/Ccld/PDF/flood_top.pdf

http://www.dep.state.pa.us/dep/deput...ODS/fs1958.htm

I can ask the FEMA flood insurance adjuster if he's aware of any requirements (some adjusters are often wrong). Only flood insurance covers this - from rising water.
If anyone has a light bulb moment, please post.

 

[JFletcher]

Thanks guys. I'm quite experienced at residential wiring & always followed code. I've lost my electrician friends/ contacts, for odd, tough questions.
Yes, it seems odd, only fresh water - pretty clean at that, would eventually ruin paper wrapped conductors. Salt water or from lakes by a nuclear plant MELT down, I could see a problem.

Anyone know if any Official electric code - from anywhere - discusses this issue? If no elect.code discusses it, why would the UL write articles? Payola from wire mfg's?

Someone linked me an article from Underwriter's Laboratory - UL, discussing the wet paper issue. UL but didn't hint at specific actions. Just "replace wiring if the paper got wet."
Other example articles (below). AFAIK, none mention a testing procedure for romex, where to cut wire, etc. None are national code or TX.

I'll try to D/L the paper that jumper linked.
I can search an NEC copy on disk. Does anyone have an idea what NEC section this might be under (if at all). I'd appreciate the info.

In worst case, does any code forbid attaching boxes with lids - to studs - to splice on new romex sections, inside a closed stud cavity w/ drywall on both sides of a wall?
The only reason I can think of it not being allowed, is if code requires all junctions / connection boxes - even w/ lids - to be accessible w/o cutting walls open.

http://www.southwire.com/support/Gui...reAndCable.htm

http://www.dli.mn.gov/Ccld/PDF/flood_top.pdf

http://www.dep.state.pa.us/dep/deput...ODS/fs1958.htm

I can ask the FEMA flood insurance adjuster if he's aware of any requirements (some adjusters are often wrong). Only flood insurance covers this - from rising water.
If anyone has a light bulb moment, please post.

You cannot bury a j-box, tho the cover could be flush with the wall surface.

 

[redikillowatt]

Thanks JFletcher,

You cannot bury a j-box, tho the cover could be flush with the wall surface.

I was afraid of that.
In that case, if paper wrapping in Romex got wet (> 1" or so, beyond cut sheathing) replacing the wire in a 2 story house you'd have to put a box & blank plate flush w/ drywall. Every outlet, in every room! A bit odd, but not too ugly if painted the wall color.

Or run new wire from each outlet all the way to the attic. :happysad: Hiring it done in 2 story house, that'd be expensive.

The PDF @ https://www.nema.org/Standards/Pages/Evaluating-Water-Damaged-Electrical-Equipment.aspx is pretty basic. Mostly, recommends if component should be replaced, or the mfg may be able to recondition it. No info like, "what to look for / how to test" or anything but replace

In chart (sect. 3), "Wire or cable listed for dry locations (such as NM-B) [that's come in contact with water] - marked to "replace" only.
Nothing mentioned about wet paper wrapping.

One section from the NEMA pdf:

4.6 Wire, Cable, and Flexible Cords

When any wire or cable product is exposed to water, any metallic component (such as the conductor,
metallic shield, or armor) is subject to corrosion that can damage the component itself and/or cause
termination failures. If water remains in medium-voltage cable, it could accelerate insulation
deterioration, causing premature failure. Wire and cable listed for only dry locations may become a
shock hazard when energized after being exposed to water.

Any recommendations for reconditioning wire and cable in section 3 are based on the assumption that
the water contains no high concentrations of chemicals, oils, etc. If it is suspected that the water has
unusual contaminants, such as may be found in some floodwater, the manufacturer should be
consulted before any decision is made to continue using any wire or cable products.

Sure, if there's 6 ft of water & it filled the Romex, after it turned horizontal to the next outlet, etc.
But here, fairly sure water didn't get above bottoms of outlets, much less above them.

 

[goldstar]

I think the publication from MN tells it best. All affected equipment has to be replaced. The flood waters in Houston could possibly contain anything from corrosive chemicals to raw sewage. If I were going down to work there I would bring a case of latex "procto" gloves. You have no idea what you'll be touching.

From what I remember, some of my cronies who worked at the seashore area telling me about Super Storm Sandy, water can wick up to about 10' inside NMC. The State of NJ DCA issued a letter stating the following for all EC's :

If panel was under water :

• Pull the meter
• Clean and dry all breakers and bus bar
• Reinstall all breakers necessary for temporary occupancy and restoration
• Within 90 days all breakers and bus bar must be replaced. In lieu of replacement the bus bar can be certified by a licensed EC

Wiring under water

• If undamaged, no replacement is necessary

Other equipment and outlets (receptacles, switches, lighting, alarms, etc.) underwater

• Within 90 days, all equipment and outlets must be replaced

IMHO, if I couldn't readily and easily identify whether any cabling was damaged I would replace it. Remember, we're not talking about a few inches of water - we're talking about feet of water

 

[kwired]

But here, fairly sure water didn't get above bottoms of outlets, much less above them.

If cables run up from outlets they are likely fine.

I'd probably still want to know how AHJ, insurance, or whoever is going to handle it before deciding to leave them as is though.

If it didn't get high enough to get into the paper lining of the cable you have chance of leaving cable as is though. They may still want devices replaced.

 

[petersonra]

I think by the time you determined if the paper was wet inside the NM it would be cheaper to replace much of it. I think it might well be code legal to just fish it down the stud walls. Nothing says you have to remove the existing NM. Just put some new boxes in the attic and splice in some new NM and drop it down the stud cavities.

 

[gadfly56]

I think by the time you determined if the paper was wet inside the NM it would be cheaper to replace much of it. I think it might well be code legal to just fish it down the stud walls. Nothing says you have to remove the existing NM. Just put some new boxes in the attic and splice in some new NM and drop it down the stud cavities.

Well the wall board and insulation are off already. It sounds to me like the wall board wicked the water up some distance higher than the actual water line. If that's the case, I'd leave it as is, dry out the wall cavities, put up new insulation and wall board and good to go.

 

[Barbqranch]

I have been curious for some time, why do they put the paper in nm? It must cost them money to do so, so it has to save them money in some other way, or else be necessary to produce the product. :?

 

[FionaZuppa]

I have been curious for some time, why do they put the paper in nm? It must cost them money to do so, so it has to save them money in some other way, or else be necessary to produce the product. :?

fire protection is what i know that paper is for.
the PVC insulation/jacket on the wires will give off toxic fumes in fire, so the paper helps that issue.


HMWPE is available by some wire makers.
http://www.performancewire.com/wire-and-cable-insulation-what-you-need-to-know/


PVC is perhaps a old technology that is still being used, etc.

 

[mbrooke]

I have been curious for some time, why do they put the paper in nm? It must cost them money to do so, so it has to save them money in some other way, or else be necessary to produce the product. :?

Last I heard so the jacket does not stick to the wire when applied. Though Canada has used the version without the paper for some time.

But look at it it like this: would you want to be stripping paper NM or a tube with a reinforced spine:

 

[James L]

In worst case, does any code forbid attaching boxes with lids - to studs - to splice on new romex sections, inside a closed stud cavity w/ drywall on both sides of a wall?
The only reason I can think of it not being allowed, is if code requires all junctions / connection boxes - even w/ lids - to be accessible w/o cutting walls open.

There are splice kits which are UL listed for Non-accessible applications:

3-wire
http://www.homedepot.com/p/Tyco-Electronics-Romex-Splice-Kit-3-Wire-1-Clam-CPGI-208169-2/202204327

2-wire
http://www.homedepot.com/p/Tyco-Electronics-Romex-Splice-Kit-2-Wire-1-Clam-A22899-000/202204326

I've used one before. They're around $7.00 each and it took 20 minutes. For the time and money, I'd rewire

 

[JFletcher]

fire protection is what i know that paper is for.
the PVC insulation/jacket on the wires will give off toxic fumes in fire, so the paper helps that issue.


HMWPE is available by some wire makers.
http://www.performancewire.com/wire-and-cable-insulation-what-you-need-to-know/


PVC is perhaps a old technology that is still being used, etc.

I doubt the heavy paper in NM helps with the toxic fumes. vs an equal amount of pvc, yeah, but it's not needed at all imo. PVC is a hell of a lot cheaper than Teflon (plenum rated cable).

If I had to rewire a house in a flood, and it was likely to happen again, I'd wire the whole thing in UF and charge accordingly. Never would have to rewire it again if it flooded.

~~~~~

I was going to mention those Tyco/TE Connectivity splices but using those house-wide would be a serious exercise in masochism.

I'd also think any house with flood damage would have enough of the drywall removed as to make installation of new wire fairly easy. 1st floor, I would remove the bottom 4' of board. I dont see a need for splices or j-boxes everywhere.

Last I heard so the jacket does not stick to the wire when applied. Though Canada has used the version without the paper for some time.

But look at it it like this: would you want to be stripping paper NM or a tube with a reinforced spine:

They make strippers for UF that work great.

http://www.homedepot.com/p/Gorilla-UF-Stripper-10-in-Cable-Stripper-46200/205072204

 

[James L]

I was going to mention those Tyco/TE Connectivity splices but using those house-wide would be a serious exercise in masochism.

That's a great way to put it. But he asked.....
:blink:

You know the difference between a sadist and a masochist?
A masochist says "beat me" and a sadist says "no"

 

[mbrooke]

They make strippers for UF that work great.

http://www.homedepot.com/p/Gorilla-UF-Stripper-10-in-Cable-Stripper-46200/205072204

Its not the same as the easy clean stripping of paper NM. Trust me, if I had to strip NM all day I'd rather paper then something resembling UF.

 

[JFletcher]

Its not the same as the easy clean stripping of paper NM. Trust me, if I had to strip NM all day I'd rather paper then something resembling UF.

Me too, tho rewiring a flood damaged home is not a daily thing. I'd give (well, sell) the HO something that would never need replacing due to flood again. I might even do it same labor cost and write off the extra time as charitable work.

 

[Buck Parrish]

The main problem with water is obviously the connections.
But the next main thing people overlook. If the wire is nicked somewhere. Boy it will really corrode in that spot. I've got a video of me finding #6 copper romex that had condensation clinging to the wires and running into the outer sheath. That water ruined it. It was just a big glob of corrosion..

 

[mbrooke]

Me too, tho rewiring a flood damaged home is not a daily thing. I'd give (well, sell) the HO something that would never need replacing due to flood again. I might even do it same labor cost and write off the extra time as charitable work.

How do we know water wont get into the jacket regardless? Nowhere is a perfect or snug fit guaranteed around the EGC and conductors.