Thanks for your reply! The beams were laid on top of a couple of rows of solid bricks. Extremely difficult to get access to, without a huge cost. The poured concrete isn't really in a bad condition - but does need to be
water proofed. I'm going to clear around the perimeter of the house, dig down a bit, dump broken tiles and then concrete over. I have found that although the septic tank
runoff goes into the ditch in front of house, the other bathroom/kitchen sinks empty via individual drain pipes onto the land right next to the side of the house. My mission - to capture rainfall from roof into water storage tanks, and dredge my ditch to keep flow of water away from property.