A cold thrill of fear still runs through me when I prepare to drill holes in a new part of the house. It brings back memories of my disastrous early DIY attempts in our first house, a 1920s bungalow. The project was shelving installation. I carefully marked out where the holes should go, got my cordless drill in position and - CRUNCH! Instead of cutting through the wall, the drill bit spun and screeched. Instead of a clean hole, I got a big, dusty crater. Oops. I knew I'd done something wrong...but what?! Friends, it was my first close encounter with a masonry wall.
So how does the amateur DIY'er know what material a wall is constructed from? Simple. Drills go through drywall easily and smoothly. You'll get just a little dust come out of the hole. If you hit wood, it's a little tougher to drill through and you might see some shavings. That means you've struck a beam. (Hopefully, on purpose!) But if the drill spins and screeches as described above (and you've checked that the bit is securely locked in position), you likely have masonry walls. This is most common in older houses like our old 20s bungalow and our current 1948-constructed bungalow.
If you have problems drilling masonry, put down the drill and back away. Don't keep trying to drill your holes (like I did) because you may get whole chunks of the masonry start to crumble away (gulp, like I did). Eeek! Here's what you do: put away the regular drywall or wood screws. They are no use here. Go to the hardware store and get some screw-in drywall anchors. While you're there, replace your cheapo standard drill bit (yes, the one that came free with the drill) with a titanium one. With any luck, it should then be smooth sailing. Good luck!