The laying course uses bradstone bedding aggregate a 6mm angular open graded material unlike normal bedding sand it is free draining and therefore it does not require any control on moisture contentr r the laying course should be 50mm thick rather than 30mm for conventional paving and it is not compacted before the blocks are laid once laid and prior to jointing a light pass over with a whacker plate with a rubber mat is requiredr r the preparation and levelling of the bedding surface