I am having a parquet floor fitted Herringbone Style. They are 15mm Blocks. I have floorboards which are quite solid. The guy who is fitting this has told me, who is quite experienced, as he has been laying these floors for 40 years, he is going staple and glue 4mm hardboard down as the base. Is this correct? He is also repairing an original floor in my hallway, which is laid directly to the floor boards, i think it is glued and nailed with six pins and filed with putty apparently that is how they used to do the parquet flooring, also to sell the houses by putting this flooring down. He is filling this with a mixture of saw dust etc. Is this guy right about the base and the filling in the hallway.