I am hanging a TV in a narrow wall space that has no studs behind it. I have verified there are no studs behind the drywall by using two different stud finders (a cheaper and a more expensive model). Both devices did go off once, but only in a small area in the middle of the wall, not along the whole height, so it's definitely not a stud.
This TV mount requires 4 screws. The original plan was to use 4 toggle bolts (a.k.a. drywall screws). However, after pre-drilling the holes, I found that there is another hard surface that begins about 1.5 inches after the drywall. There is no room for the "butterfly" part of the toggle bolt to open up. I don't know what the hard surface is. When I give it a knock with a screwdriver, it sounds like either metal or brick. This is an apartment building over 100 years old. There is another person's apartment behind the wall. A few questions:
1) Should I do additional testing to find out if that surface is brick or metal? If so, how?
2) If not, should I assume it's brick and proceed with trying to put the screws into the brick, either directly or with anchors? What kind of additional gear would this require? Special screws, drill bits, anchors?
3) Alternatively, should I stick with the toggle bolt method, which would require drilling large openings in the second surface to allow for sufficient clearance for the toggle bolts to open? Not sure how easy this would be.
Thanks!
Best Answer
An over-100-year-old apartment building is likely plaster-over-lath. In that case, you should be able to drill through the plaster and into the lath to sink wood screws. If this is so, you'll see what looks like sawdust on the tip of the drill when you pull it out. I'd probably use a bunch more than just the 4 recommended, but it'll hold a TV under 50 lbs.
If you want to find out what's behind there, just try to drill it (with a drill bit you don't care about). If the tip comes back red and chewed up, congrats, it's brick, and you can sink masonry anchors if you want complete overkill. You'd need to drill with a masonry bit, and then you can choose either expanding anchors or epoxying in something more like a drywall anchor.
This ain't a job for toggle bolts, though.