IVE JUST BEEN TO PRICE A BATHROOM THAT NEEDS PLASTERING AFTER TILES HAVE BEEN REMOVED.THREE OF THE WALLS ARE STUD WALLS COVERED IN REALLY POOR CHIP BOARD.THE OWNER DOESNT WANT THESE BOARDS REMOVED COS OF THE MESS.I SAID I WOULD OVER BOARD WITH 9.5MM BOARDS AS THE WALLS ARE FAIRLY LEVEL,AM I RIGHT TO DO THIS?JUST LOOKING FOR A BIT OF REASSURANCE REALLY.