How can I tell if there is electrical wiring beneath kitchen tiles?

Mr T · 01-03-2009, 05:14 PM

Hi Guys.
I have a problem in that I need to put up some shelving on a tiled kitchen wall.
Unfortunately one of the support struts would need a drill-hole directly above a double socket, and I have no idea whether there is any electrical wiring in this area. Underneath the tiles there is brick, part of an exterior double brick wall. The drill holes would be about 1ft and 2ft above the sockets.
Am I in trouble if I drill here?

Is there something(Zircon gizmo?) I can buy that will tell me if there are live wires beneath tiles?

Just Bill · 01-03-2009, 07:30 PM

Better stud finders have electrical detection also. But I would bet that there are wires above that outlet. The wires either have to feed from the top or bottom, and most of the time it is from the top. The wires are supposed to be stapled within a few inches of the box, but there is no guarantee.

Chemist1961 · 01-04-2009, 07:27 AM

Try pulling the cover on your receptacle and look for the old wire path. If you have tile over brick, it's likely the electrician ran back behind the brick through the studs supporting the brick, rather than through the actual brick. If that's the case and the shelves aren't too heavy you may be able to anchor into the brick. For drilling through your tile, get a drill bit rated for glass. Carbide masonary type will take forever.

Bob Mariani · 01-04-2009, 08:02 AM

Chemist1961
why would carbide bits made for this application take too long? maybe you are using a drill and not a hammer drill? Drill bit for glass.. to only difference is this uses finer diamonds and more of them. Brick is very soft and easy to drill.

Bob Mariani · 01-04-2009, 08:05 AM

If the anchor is directly over the center of this outlet you should have no problem. Wires in brick should be in conduit. Even if this was done wrong the wires would be stapled to the side of the stud. If the wire is drilled thru the stud a metal plate should have been placed over it and the hole needs to be 1 1/4" back from the surface of the stud. Detection is also flakey on this. So bottom line...maybe no issue.. but you cannot assume something was done correctly. Turn off the electric... drill hole carefully... check electric... if you damaged it... replace damaged line.

Chemist1961 · 01-04-2009, 08:40 AM

Bob is right about bits for most brick. As stated the carbide bit should be fine for typical masonary. But we also have tile involved. Depending on the firing of the brick but also the type of tile, a glasss rated bit should handle both. If the tile happens to be porcelian, a glass rated bit is the way to go. If it's ceramic and you damage it you have a bigger project so again, the glass bit for special occaisions like this is a good investment and a time saver.
I drill through ceramic and porcelain about once a month. I ran a satellite cable though my brick several years ago at rim joist level. It was like hardened steel.
I have both a 1/2" Milwaukee and 3/4" Makita Hammer drill as well a s a BOSCH with 3 inch core bits in my toy box. The glass bit is the best $5 I`ve ever spent on bits. I burned out at least 4 industrial carbide bits on my outside brick. Last fall I bought the glass bit for an indoor job. Money well spent. Mine were made by MIBRO.

Bob Mariani · 01-04-2009, 09:16 AM

sorry... missed the tile.. narrow focus was on where is the wire.

InPhase277 · 01-04-2009, 10:35 AM

I pity you the fool!

Mr T · 01-04-2009, 05:40 PM

Thanks, Guys ... erm .... except possibly InPhase

We've decided to hack a bit off the ends of the shelving and move the support strut to the side( and above ) of the sockets. But I shall take your advice and isolate the electric before drilling anyway.
I've been told that masking tape over the tile will help with drill-slipage, just hope that the tile doesn't crack!