What are these walls made of?
On the other side of this wall in my apartment is the hallway in my building. When drilling it's solid and I got black dust coming back on 1 hole and then on the hole 2 feet beneath I got reddish dust coming back. Trying to hang twin racks for shelving and thought to use toggle bolts, but I'm unclear as to what it is that I'm drilling into and want to make sure I'm using the right fasteners and the right bit. I put a few items on what the existing hardware was (seems like metal screws with plastic anchors) and the shelf came falling down.
If using toggle bolts, could I reuse the holes?
There are some great links with a lot of info on plaster...