We have thin concrete walls in our flat, ~7cm/2.7inch thick. I need to drill some 6.5cm/2.5inch deep holes with a diameter of either 10mm/0.4inch or 8mm/0.3inch (I prefer the wider but can live with the slimmer) in order to attach a wall bracket for a heavy floating board. So almost drilled through. I can live with drilling through though - applying some filler and adding a piece of wallpaper afterwards is something I can accept.
But how do I make sure that no debris breaks off from the other side of the wall? Or, at least, lower the chances?
We made shorter holes in such walls before (I think it was 5.5cm/2.1inch deep with diameter 8mm/0.3inch), and it already occurred twice that a piece of concrete broke off from the other side. One piece was as large as a palm of a hand, the other was a bit smaller. In both cases we had to apply a lot of filler to the wall and were not able to conceal that damage was done - the filler shrinks when drying, leaving a visible dent. It's not that the dents catch the eye immediately, but they are still easy to spot.
I am not afraid of statics issues. I merely want to have a nice-looking flat and not one with construction site vibes.
We use a rotary hammer for drilling the holes (this one), and we cannot use anything else. I know there are concrete walls that allow usage of hammer drills, but our walls are too hard: My husband once tried it; it took him 45min (and a lot of musclepower and sweat) to get 3-4cm/1.2-1.5inch into the wall, then he couldn't get any further. And this was just 6mm/0.23inch diameter.