Have a job where walls are clad with osb ( trendy). Customer wants walls partially tiled around all the worktops with larger splashbacks behind cookers and sink etc. As the walls will be partially tiled you will be able to see the top edge and side edges. I am using Hardie backer 6mm on the osb. How on earth doni trim the edges without showing the Hardie backer behind. Customer does not want me to chop out osb and replace wiyh backer