It’s advisable to add 10% to the total number of tiles when planning for straight tiling. For diamond pattern, 600mm x 600mm or larger tiles, it’s recommended to add 15%. We also recommend purchasing an extra box or two before the project starts. It can be difficult to match the same tile or batch if you’re going to request it years after the job is complete. This will make the process of replacing tiles a lot easier in the future.