Crap at DIY...

[delboy]

So I finally made it to Screwfix to buy my Stud finder. Came home, set the detector to "Wood", ran it across the wall where I want to hang the TV and it bleeped perfectly. Several passes from each direction and I've got the location of the wooden baton nailed, excuse the pun.

The wall bracket for the TV is very narrow and only has two fixing holes, one above the other, so it's essential I hit the baton. The one I've found isn't quite in the centre of the wall, but it's close enough to pass muster.

Start drilling with a wood drill and immediately hit something solid that a wood drill won't penetrate. Try the second fixing hole three inches below. Same result. Hmmm. Now I set the detector to metal and sure enough it finds something metal in exactly the same position as it found something made of wood.

Now the only time I've ever had something similar happen before it was a water pipe behind the wall. That time I stopped drilling in time. This time I'm obviously reluctant to carry on. On the other side, the far side of this interior wall is a shower, so I know there will be water pipes and cables in the same cavity, but according to my observations these are all below the point that I'm interested in, and I can't see that any pipes would run upwards. There are no pipes in the loft space, and none running upwards from the water tank (which is on the same floor as the shower, not in the loft space). So I reckon any pipes would be running downward. So, what might I be hitting? Electrical wire protection? Metal rather than wood batons?

I'm at a loss to what to do next, beyond cutting out some of the plaster board in the attic to get a good look into this interior wall. If it helps, the house is only a few years old, so the interior walls are likely to be of a modern design.

Cheers,
Del

[Ed]

Sounds like you've got a metal stud wall, Del. Many sites use metal studs in preference to wood these days, because it's a lighter material and it doesn't warp. You can test the theory by setting your stud finder to metal and seeing if it registers a hit at either 400mm or 600mm away either side of the stud you've found.

I'd guess most of your pipework is likely to be plastic, and I very much doubt any of your electrics are within metal conduit, or even plastic conduit. The only other thing it's possible it might be is a gas pipe, which would be in copper, but I very much doubt you've got anything running on gas in that vicinity. If it was me, I'd make a separate hole that will be covered by the bracket and enlarge it slightly with a screwdriver to about half an inch square. Then if you can see a flat galvanised surface you're almost 100% sure it's going to be a metal stud.

[digitaldeath]

Try and listen to an old record by Flanders and Swann. It may be called the worker's lament. A householder finds there is no gas coming out of the pipe so on monday the gas man comes to sort the problem only he rips up the floor so they need a carpenter the following day, he make a hole in the water pipe, the plumber breaks a window and the painter paints over the gas pipe. So the gasman...
I'm a professional photographer, there are two types, those who are good and those who want to make money and rip off the public. It is the same across the board, a good home diy man can be better than a pro. If you cock up you just call someone in and say you were trying to impress your wife.
Humility is free.

[delboy]

Cheers Ed!

Then if you can see a flat galvanised surface you're almost 100% sure it's going to be a metal stud.

If this is the case then I guess attaching a TV is a no no? The pictures I've seen of metal stud walls look like there's nothing behind the metal to screw anything into. Could be an easy solution after all... 

Del

[Caz]

You could always slot a lump of 4 by 2  timber into the metal stud, but you'd have to tear down the plaster board to get at the stud in the first place. Rather more drastic than you want to be I guess.

[Ed]

Cheers Ed!

Then if you can see a flat galvanised surface you're almost 100% sure it's going to be a metal stud.

If this is the case then I guess attaching a TV is a no no? The pictures I've seen of metal stud walls look like there's nothing behind the metal to screw anything into. Could be an easy solution after all... 

Del

Depends on the weight of the TV, really. Chances are you'll get a good enough fixing straight into the stud, as long as you don't overtighten the screws. The plasterboard gets fixed onto them with standard black plasterboard screws, but if you can get your hands on a couple self drilling and tapping screws, like they use for steel cladding on factory buildings, they'd be ideal. Failing that, any old hard screw will start itself and screw in. Most of the load is straight downwards in a shearing motion, so the fixings aren't likely to pull out. As Caz says, your other option is to open up the wall and place a noggin between the studs, but that's going to take a fair bit of making good afterwards.