Extensions

Single storey built on a raft?

Anonymous user 23/02/2024 - 3.06 PM

Good evening Thank you to whomever takes the time to read. Firstly I must apologise as I'm a lady who knows little about buildings works so please forgive my lack of knowledge. We have just purchased a house that was built in the 1900s. It had an extension all across the back of it at some point. We are not sure when as there is paperwork for it nor do the council hold any. We were wanting to find out if we could build a second storey on top of this existing extension so we have dug 2 inspection pits. One at the front of the extension. This has drains running all the way along the front. (The long ones for water waste) The only "solid" thing we can find underneath here is the concrete which the drains are set in, this is less than 7" deep. Below this is clay. Not too claggy clay but still clay. There is no concrete in front of the drain. The second inspection pit we have dug is at the side of the extension. It has shown concrete to the same 7" depth but it also runs sideways from the house. I.e. Sticks out. Our house is built on a hill and slopes towards the side with the concrete sticking out. Inside the house on the side where the drains run in front there is a concrete platform that the floor is on. It's a good 1" and a half higher than the other floor. Outside to the other side of the extension (near the drain side) are the main sewage drains. For some reason these are above ground level. So, (thank you for staying with me) what we think we gather from this is the extension has been built on a raft? And maybe not even at the same time. We think one side may have been added later than the other. And if we are by any chance correct, we don't believe it to be a very substantial raft. Would this mean it would not carry the weight of a second storey? Or have we dug in the wrong place to find the foundations? Any help or advise would be very much appreciated. We are waiting for building control to get back to us but as yet have heard nothing.