Lightning hit house

[Jerry Maxwell]

Hey folks,
I am not an inspector, but I would appreciate any information that you can provide. My house was hit by lightning 6 weeks ago. It entered the roof and exited through the siding. It fried most of the low voltage wiring as well as some of the appliances. It also damaged some minor structure in the attic, roof and all the sheetrock in the upstairs rooms.

I have been concerned about the electrical wiring and can't seem to find information about what should be inspected and how. I hired a disaster recovery company for the repairs (bad choice). one line item they had was a megameter check. I talked to the electrician who performed the check, he said he just spot-checked some of the outlets, switches and breakers to see if they were functioning. I am concerned about the safety of my wiring and can't find anybody who knows anything.

Am I overly worried? Any suggestions?
thanks
jerry

[rcramer]

Hello Jerry,
About three years ago when I was doing insurance restoration work as a contractor, I was called to a home that had been struck by lightning. To make a long story short; the jolt hit an I beam in the attic that supported the roof structure and then exited the home out a side wall next to the gas meter…..very lucky. The home owner had problems from day one with the electrical system and eventually the home was almost entirely rewired. They also had other problems; as the lightning fried the heads off nails. The homeowner noticed shingles, siding and soffit pieces falling off the home. It was determined that the entire roof, siding, soffit system and gutter system needed to be replaced.
I would highly recommend that you have at least three licensed electricians evaluate your electrical system. Additionally I would recommend that you hire a structural engineer to evaluate the structural integrity of the home. Get your insurance company involved, as they should pay for all of these services.

[Jerry Maxwell]

Thanks, Robert.

Some of the roofing and decking has been replaced. The only thing in the attic that was repaired was a horizontal 2.4 that the lightning blasted in two. The siding and soffet is being replaced right now. I will get another electrician out to look at the wiring. The disaster recovery company is an old established company, but I am surprised that the guys that I have talked to don't seem to understand what should be done for the electrical wiring.
Their software program calls for a megameter check, but no-one seems to understand what that is. I have read info about a meg ohm meter test, but I know they did not do that.

jerry

[jking2]

Any Master Electrician should be able to perform a meg ohm test of each circuit to verify the integrity of the insulation. If any circuit is found to have inadequate resistance, each leg of the circuit can be isolated and tested to identify the exact run(s) of wire that must be replaced.

Jim King

[Marc D. Shunk]

Indeed, a megohm meter check, at 500VDC MUST be performed on each and every branch circuit of a home that has taken a direct lightning strike, flood, or fire fighting effort. This is very labor intensive. It's not so much physical, but it takes an awful lot of time. When you find a non-conforming branch circuit, then you're taking apart sections of that circuit to pin down the bad piece. I've never managed to completely megger, troubleshoot, and repair a dwelling for less than 2 grand. Often, it can run into more. For a labor metric, I use 2 hours per circuit, so that will give you an idea of what sort of time is involved with a megohm check of a dwelling.

A few reasons this is so labor intensive, troubleshooting aside, is because all dimmers and GFCI's need removed and jumpered. All light bulbs need removed, and all ballasts need disconnected. All cord and plug connected loads need unplugged, and all direct wired loads need disconnected. The megohm test is performed at twice normal operating voltage, so these things need disconnected so they don't get ruined during the test.

A note to the HI's in central PA or near the Mason-Dixon; I am one of the few EC's in my area that performs such testing in dwellings, with a complete circuit by circuit report, should the need arise.

[Marc D. Shunk]

A note to the OP... since you're reasonably sure that a proper megger test was not performed, in my opinion you have two options. Insist that one is performed, and insist on a copy of the report OR insist on AFCI protection for each and every branch circuit in the home.

[pdickerson]

Marc is correct about the need to evaluate ALL of the home's branch circuit wiring. I have seen first hand what a lightning strike does to residencial wiring. I few years ago I was involved in some repair work on a home struck by lightning. About 30% of the branch circuit wiring had exposed conductors from where the strike melted the insulation. Spot checking??? I would't sleep in it