Which side is which?

I'm trying to install a 'picture rail hanging system' and I need to drill holes in my wall about 1cm down from the ceiling. After drilling in just 1cm, the drill hits something solid, no matter where across the wall I drill, it always hits solid after just under 1cm. Could be steel or some sort of heavy duty concrete. Either way, I've tried 6mm masonary drill bit as well as high quality steel drill bit of 6mm also, but nothing goes through. Any ideas? Thanks

Hi all, I'm planning to redo our spare bedroom and I'm not sure how or whether to proceed. Our 2-story house is fairly old (about 80 years) and the spare bedroom and kitchen below are part of an extension (i.e. outside the basement perimeter). Although we have central air/heat, the kitchen tends to be cold in the winter, though the bedroom is not as bad. The bedroom currently has both a drop ceiling and paneling, the only room in the house that has paneling. I've always wanted to tear down the paneling and drop ceiling and paint the walls, but after investigating yesterday I discovered that there is a thin (~ 1/2 inch) layer of insulation above the ceiling panels and between the paneling and wall. Knowing that this room was used by the previous owners' two small children, I have a feeling that the insulation was installed to keep the room warmer in the winter for the kids. So, my issue is that I still want to take down the paneling and ceiling, but I also don't want the room to be uncomfortably cold in winter either. Any suggestions? Would drywall be an option? Thanks, Steve