Am renovating my new house. Under the hall carpet we have found parquet flooring which appears to be in good condition apart from the fact that most of it is loose. As the concrete floor under it has sunk in places I intend to lift and relay the whole lot after levelling the floor. How do I get the old bitumen off the blocks. I have tried a hot air paint stripper gun which works but is incredibly fiddly and time consuming. Do I even have to get the bitumen off or just ensure the base of each block is reasonably smooth? Any help or advice appreciated.