I picked a TV mount from Ikea. The TV itself is being mounted to some paneling which in turn is mounted to set of wooden draws. In addition, it gives you hardware to mount the panels to the walls. It's not really meant to support any weight, just to keep it from swaying back and forth. So I picked up a cheap stud sensor (Zircon E30) but I'm not having very good luck with it. As soon as I start sliding it, it usually just starts indicating an error. Occasionally it tells me there's a stud, but on subsequent passes the results are far from exact. Right now I think I have an idea of where two studs are but it's a very rough guess.
I'm wondering if this is because this model is junk, or could I have lath and plaster walls? I'm pretty sure the walls are not drywall, just judging from the way they have crumbled when I tried to put a screw in them previously. Usually the paper coating on plaster doesn't allow it to crumble like that. Plus drywall usually seems to crumble more into a fine powder and this crumbles more into sand or little pebbles.
So does anyone know if there's a way I can tell if the walls are lath and plaster? Or does anyone know if this stud finder is no good? They do make a slightly more expensive model which is supposed to work better with lath and plaster walls. I just don't want to go and spend the money buying if it I don't really need it. Plus I'll probably wind up using it this one time and never see it again.
Any suggestions? I did try knocking on the walls and trying to hear a difference, but that wasn't really working for me.
edit: I just wanted to let people know I used this sensor: http://zircon.com/products/metal_m40.html and it seemed to work pretty well. So if you have lath and plaster walls, might want to give that one a try.