I'm investigating the feasibility of modifying my garage roof to increase the headroom in order to allow the installation of a 4 post lift to store a classic car. It's a double garage about 30 years old of single skin brick construction with a trussed roof.
I'm in discussions with a structural engineer regarding the roof modifications that will give the greater headroom required. I'm also looking to confirm there won't be any issues with the floor. As I have no information on the garage floor construction the engineer suggested using an SDS drill to ascertain the floor's thickness. I've done this and it's 20cm. The colour of the powdered concrete was pretty uniform and the resistance to the drill seemed pretty constant all the way down. No indication that I hit any rebar - perhaps I was (un)lucky? But there's then a 19cm void below this before I hit mother earth. I've used a borescope to confirm these distances.
I was not expecting such a void. Any ideas what sort of garage floor construction this might be?
I'm in discussions with a structural engineer regarding the roof modifications that will give the greater headroom required. I'm also looking to confirm there won't be any issues with the floor. As I have no information on the garage floor construction the engineer suggested using an SDS drill to ascertain the floor's thickness. I've done this and it's 20cm. The colour of the powdered concrete was pretty uniform and the resistance to the drill seemed pretty constant all the way down. No indication that I hit any rebar - perhaps I was (un)lucky? But there's then a 19cm void below this before I hit mother earth. I've used a borescope to confirm these distances.
I was not expecting such a void. Any ideas what sort of garage floor construction this might be?