I've bought my house a year ago and under my stairs i have a handrail that just goes straight in the floor. Obviously there used to be a basement but when i know the concrete it doesn't sound hollow. Is there a way to check if there is a space behind the concrete and how large it is without damaging anything ? Or is the only way to drill ?( preferably really cheap/houshold hack stuff since since i'm not the richest of the bunch ) via /r/DIY http://ift.tt/2z8goWq
