Needed to remove the old ply floor on Friday afternoon, it was in a bad state so I won't be re-using it, but it has one use left. As a template! The ply was screwed down and I managed to remove most of them, but there's always the odd one, where the head chews up . After removing all the ply there was a bucket full of mud to clear up. After a quick Hoover up, it just needed a wash.
Then I was able to get on with fixing new battens and insulation.the battens are 30 x 50 and stuck down with Sika.The insulation used is celotex 450 x 1200 batts which are 35mm thick.Ive used these as I have a whole pack left over from a job.The insulation is stuck down with pv foam.Then 12mm WPB ply is used for the new floor.