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Hmmm....have one in the closet from my relic hunting days....might be worth a shot.

I've seen others that could "witch" cable, but I never could. Might be worth a try.

Have to ask- why did they bury the cables under the roofing? Was that the way they were with the old roof? Didn't they think that maybe they should have consulted with you guys before doing this?

Sounds to me like the roofer and maybe the GC are responsible for this. And that sounds to me like you should be able to get any kind of locating gear that will work out of them since their only alternative is to remove the membrane and start over.

They should be kissing your ass! :bow:


-Hal

Like I said, this job is a mess. It's happened quite a bit, around here after Ivan. The original "contractor" was using unliscensed people...etc.etc. When I was there today for the meet, the new contractor who we have done these jobs for before, was in the process of tearing out the ceiling tiles because the previous guy had failed to get permits for anything and the City has shut them down. When I walked in the front door, I actually saw a 200lb chandelier's junction box mounted to a sheet metal duct. The enire weight of the chandelier was being supported by the duct. The new contractor is just having to fix all the screw ups at this point. I can almost understand them covering the downleads up, keep in mind the enire roof along with the old aierials was nearly blown all the way off, I'm sure there was not much of anything left for the roofers to cover up except for the stub throughs from the grounds going down. Add that to the "It's not my job" attitude and whala...here we are. We talked some more with the GC today and he agreed, we will try a few holes to find the old grounds, if no luck, will run new ones down the sides of the building.

Whenever a building owner replaces a roof with either a rubber or PVC membrane, they frequently want the warranty that goes with it (assuming a qualified roofing contractor). If this is the case, the roofing inspector (from Firestone, Carlisle, or whomever else) can be your ally. My neighbor is one of these guys, and I've heard horror stories of what he's made roofers do to do the job right. Hope my two cents helps a little.

The Greenlee tracer will work, it will provide tone even on a shorted to ground line. I have home builders that have used it to find buried ceiling heat ducts behind drywall, even though the ductwork is grounded. It will also work on live power as well, great unit, not cheap though. Here is a pic: https://www.newark.com/product-details/text/catalog/80184.html

Also/or, the cables are copper right? A good quality metal detector that can discriminate between types of metals should be able to find them.

Whenever a building owner replaces a roof with either a rubber or PVC membrane, they frequently want the warranty that goes with it (assuming a qualified roofing contractor). If this is the case, the roofing inspector (from Firestone, Carlisle, or whomever else) can be your ally.

I know exactly what you are saying, my wife with her former husband had a big commercial roofing company. I don't know if what you say is going to work in his favor. Cutting holes in a new roof and then patching is not exactly a good thing. It would be done by the authorized contractor which would mean that it should still be covered by the warranty, but unless you can keep it to a minimum it's not a good thing and the inspector from the manufacturer may not like it.

It would be a shame if you had to run new cables on the outside of the building. The existing ones are probably far superior than what you can expect from driven ground rods. They are probably connected to the footing ufer ground system.

Too bad that this whole job is so screwed up. I guess all you can do is do what has to be done, collect your money and don't look back.

-Hal

Not sure if it would work for you, but try your regular toner & wand. I've used it on a fishtape behind 2 layers of sheetrock and touching metal studs (grounded, of course) and it worked ok.

Since you're grasping at straws here, I've got a bit of an off the wall suggestion. When sweeping for eavesdropping devices we use a special probe to search for audio that is passing along pipe etc. It got me to thinking that maybe you could create that situation to your advantage. I took a transducer and placed a low frequency bass hum into a ground wire, then had one of the guys here take a shotgun mic and see if he could find it using it like a stethescope. He could actually hear it pretty well.

Keep in mind that the structure here was wood however. If it was a steel structure I imagine the hum would radiate everywhere.

I know it may be a long shot. It's just the kind of crazy thing I'd probably try if someone told me I couldn't do it. :idea: