Posted: Fri Sep 01, 2006 7:25 pm
We'd like to have our currently concrete drive re-surfaced with tarmac. The builder wants to excavate to a depth of 225mm before doing the sub-base etc. However, we have some steps going down to a cellar such that there is a void underneath part of the drive. There are some concrete slabs keeping the roof of the void up, with the thin concrete surface of the drive over them. This means that it won't be possible to excavate to 225mm in that area before building the tarmac surface up. Is there anyway to lay tarmac on top of concrete to get round the problem and which won't quickly degrade as we've heard?