just for the record guys i am a flooring installer however it is normaly laminate hardwood or karndean floors i do, tiling iv'e ony done a few times so it takes me a while to get it right but i get there measuring and cutting i do all day every day just diff tools, setting the job out and getting it flush i can already do just some of the technical stuff i need a little help on. this floor isnt one i can walk from it would cost future work and probably a lot of future work so i need to get it right. as most you guys will have experienced some tilers will turn up and say it can be done regardless of problems, my customer is a fairly clued up guy but he like most customers wont part with cash unless i can explain why the floor will fail if he doesnt follow the correct procedure, i've learned a lot just looking through the posts here. there was existing tiles in the kitchen area in this job for years that were fine on just 9mm ply so getting customer to pay for the extra ply was just in the way of peace of mind for him. fortunately he knows im not a tiler so there really wouldnt be a comeback however i won't do the job if i know it will fail as i wont do that to anyone.