Lightning Strike

[NTesla76]

Have any of you had personal experience with a home that has been struck by lightning in terms of possible on going issues? I understand the immediate issues with a fire and burning of the structure and materials. Has anyone re-wired an entire house if it was struck by lightning? There were storms roll through in this area last night and 2 structures were struck and had small attic fires. Just curious.

 

[Fred B]

If lightning strike directly interacted and effected the homes electrical system, voltages induced likely exceeded the insulation testing limits for the rating of the conductors on a strike that caused fire from electrical system. Without performing an insulation resistance testing you have no way to confirm the condition of the conductors. If looking at the equipment, conductors, receptacles, and switches and any damage apparent, most times just easier to replace and rewire than to test every line and splice. Cost factors can influence the decision as cost to test used to be sufficient that if there was any question as to condition it was cheaper to just replace rather than test and still have to replace.
It has been stated that the method of insulation testing can damage the insulation of an otherwise sufficient wire. Cannot verify that, but does seem if you limit testing voltages to the correct listed limits (wire rating should allow a momentary surge in excess of max rating of wire) it shouldn't damage an otherwise non compromised wire. I've read those limits at one time just dont recall the actual numbers.
Another consideration is water damages to the electrical system from the fire fighting efforts. If paper in the NM is wet it is considered compromised. IR camera is particularly useful in helping with determining that.

 

[NTesla76]

I know my sisters house was struck twice within 5 years after building it. They've been there almost 20 years now. A few months ago, a receptacle in the wall in their basement burned up and wasn't being used. Could have been a variety of things, but the lightning strikes came to mind as well.

 

[gadfly56]

Growing up, our house had a near hit in the 70's. A tree about 15 feet from our living room was struck, and the TV in the living room was destroyed. No other apparent issues. My siblings live there still and haven't reported anything amiss.

 

[hillbilly1]

I’ve seen nailheads popped out with burn marks under them. I will usually Meg everything. I subbed for another contractor because he had never megged anything before, lightning had hit the flag pole at a mortuary. Panel was in the prep room with a dead body on the slab. Contractor would not go into the room until they removed the body! LOL!

 

[Knuckle Dragger]

I have repaired, replaced, and completely rewired houses struck by lightning. It all depends if it was a direct strike and the intensity of the damage.
The worst damage I saw shy of the house burning down.
The lighting struck through the roof effecting what I deemed the entire electrical system in the house.
Random devices, plates, fixtures blown off boxes.
Walls and ceiling cracked.
Romex whipped so hard it ripped through gypsum board.
Individual conductors in Romex torn through the sheathing.
The insurance company didn't believe us when I said it needed a complete rewire.
The sent an in another contractor to Megger it out. He took one look and said he wasn't passing any of it no matter what the meter reads.
Note:
This was a duplex condo.
Very limited damage on the other side.
Go figure.

 

[ptonsparky]

We do area civil defense sirens. One took a direct hit. The 6 bare running down the pole whipped against a parallel 1” EMT leaving a dent down the conduit and fittings.