Your local building dept. will be the ones who issue the guidelines for exactly what must be done, often dictated to them by the insurance indusrty. One thing I can tell you for sure is that anything electrical that has been touched by the floodwater must be replaced, whether you are told to or not. When the guidelines for repairs from hurricane Katrina began to spread, and we were told that any wires in the structure that had been touched by the flood waters had to be removed, everyone thought it was just a bunch of crap, but as we began inspecting these wires it was obvious. Once the water gets into the jacket, corrosion begins and it is just a matter of time before they short out. We expected to replace panels and receptacles and switches but the deterioration of the wires was a surprise. Every wire whether line voltage, low voltage doorbell or alarm system, or speaker wire showed the same problems. You could strip the insulation on a vertical wire and tell exactly where the water level had reached by the corrosion of the wires.It is a definate fire hazard.

 

Once the water gets into the jacket, corrosion begins and it is just a matter of time before they short out.

I'm sorry but I don't buy that. I know you say you experienced it but water will NOT cause wire to short out. I have seen my share of submerged NM cable and service cables to question this theory.

I will say, ANY and all devices that were submerged must be replaced,as well as ANY circuit breakers. It is usually beneficial to just replace the whole panel. It is rarely worth it to just replace the branch and main breakers.

 

why hasnt the statue of liberty crumbled to pieces by now. water may oxidize copper but corroade I think not

 

Ever look inside a piece of copper water pipe? The wear, pitting, and yes corrosion varies with water chemistry. Well water in my area eats holes in copper almost yearly in some homes.
As for flood water, it isn't just water, it's sewage, fertilizer, chemicals, and everything else that was washed into the mix. And if it was trapped around the wire, absorbed in the paper liner and left to crystalize inside the jacketing, yeah I could see it being corrosive.
Yes, the statue of liberty is out in the weather in a saltwater atmosphere, but it was also treated with a coating a few years back after being powerwashed and it doesn't have an outer jacket that holds moisture against the sheeting.

 

Here's an an article from the NEC Digest

Water damage
Electrical equipment may be exposed to water damage through flooding, hurricane, or other disaster. Firefighting can also cause water damage. When submerged, the integrity of electrical insulation can be compromised by moisture, metals can rust, trip units in some molded case circuit breakers can be impaired, and damaged filler material in fuses can degrade their insulation and interruption capabilities. Not only electrical distribution equipment, but motor circuits, power equipment, transformers, wire, cable, flexible cord, ground fault circuit interrupters, surge protectors, lighting fixtures, cable trays, and other electronic devices can all be affected.

"One thing that is not clearly recognized," says Schultz, "is that many component parts made of ferrous metals begin to rust or deteriorate, or parts made of aluminum completely disintegrate, and fiber material loses its shape. In addition to its corrosive action, floodwater is contaminated by various substances and will leave a conductive residue on and within electrical materials and equipment. When energized, carbonization and tracking can result, potentially causing a fire."

Flowing floodwater is particularly damaging, says Schultz. "It contains many combinations of chemicals and is laden with fine silt that will get into every area of components and equipment. In addition to the corrosive properties of this solution, the silt sediment that accompanies it also may impair the operation of equipment."

For example, says Schultz, "If you have a circuit or a device on that circuit that shorts to ground or line to line, the circuit breaker or other overcurrent device is intended to interrupt the current. If the device is damaged or its mechanical integrity is impaired, it will not operate as intended and will not fail to a safe condition, thereby maintaining the hazard it was intended to interrupt."

Typically the hazard is greatest after a flood when equipment isn't properly repaired, Schultz says, so recognizing the high water mark is key. NEMA and UL both recommend that all electrical components and equipment below the flood line be replaced, with the possible exception of submersible sump or well pumps, and cables suitable for direct burial or wet locations. In limited situations, some equipment may be reconditioned.

Link to article:http://www.nfpa.org/displayContent.asp?categoryID=564

 

Here's an an article from the NEC Digest


Link to article:http://www.nfpa.org/displayContent.asp?categoryID=564

Hmmm...

I wonder if the highlighted portion about wiring suitable for wet locations might one day be a NEC code requirement for dwellings in flood zones. It makes sense to me.

 

Here is the document, right from NEMA, that most building departments use to prescribe exactly what should be repaired and what should be replaced:

"Guidelines for Handling Water Damaged Electrical Equipment".

 

Thanks for the great information all!! Now the nasty work begins!!

 

Well, there you have it. Right from NEMA. Replace the wire.

I'm keeping a copy of that report for future reference. We do have a few areas around here that flood on occasion.

Thanks Marc & Mickey.

 

As a loss verifier after Katrina, I looked at over 500 homes that had various amounts of water damage.

Flood damage goes much farther than you initially suspect.

There is a definite difference between flooding from salt water or brackish water. In spite of that, the damage that I saw from the filthy "fresh" water was almost as bad. - I was looking at homes 4 to 9 months after the hurricane/flooding (two different events).

The fresh water contained more junk and chemicals than you can imagine. The stains and smells are obvious signs of sewerage, storm water petroleum, fertilizer (corrosive) and everything else you can possibly find anywhere near water.

Obviously, every appliance.fixture/outlet and switch even near thw water level was totally shot and had to beplaced witout even looking.

All drywall(LOL) had to be removed up at least 4'. Ceilings commonly had to be removed.

One of the biggest problems in homes that were flooded and abandoned for even a short time was the fiberglass insulation. While it does not absorb moisture, it will collect and hold it to the extent that anything near (walls and ceilings) it can corrode metals. I saw ceilings fall in shortly after the storm because of the weight of the moisture even though the roofs seems to show no damage or leaks.

It was necessary to renail all studs because the moisture held in the wood would futher corrode the connections.

It was obvious that all electrical components should be replaced since they were severely corroded OR the effective life was reduced. With the walls stripped, it is easy and is a no-brainer. You cannot afford to take a chance when the effective life is reduced even if the components were just near the water.

 

I will be the first to admit when I am wrong.

The one thing I still don't buy is the short term problems with flooding. Nothing will "short out" because it is wet. It is the long term effects I didn't know were such an issue.

 

The one thing I still don't buy is the short term problems with flooding. Nothing will "short out" because it is wet.

I wouldn't want to bet money on the conductivity of nasty water. That said, I've seen first hand a computer power strip with the rocker switch illuminated and things plugged into it submerged in a flooded basement. Kinda weird to see.

 

Oh, I've had my hands in 18" of standing basement water, only to realize that the 240v well pressure switch was still live! I was within 3-4 feet if it. :thumbsup:

 

And how about Joe T's video of a hair dryer "blowing" away fully submerged in a sink?

 

I think the hotel caught up with him and pressed charges. :laughing::blink::whistling

 

Yeah, I noticed he did this in hotels with someone else's property -AND LEFT IT WITH POTENTIAL DAMAGE FOR THE NEXT GUEST!

At least use your own stuff for your electrical experiments.