Hi there - I will be laying vinyl tiles in my bathroom which has an old and fairly uneven planked floor. My plan is to eliminate all movement in the floorboards, then lay 6mm egp ply to level out as much as poss, then lay 2mm self adhesive vinyl tiles onto this. Lifting the entire floor is not an option and I have been told by the tile supplier that the tiles will cope with some unevenness but not movement. I have been unable to source a sheet of ply big enough for the entire room, therefore there will be 2 joins. I need a product to seal the joins and prevent any independent movement in the ply sheets. I have been recommended Ardex feather finish, but cant find a local supplier (and it only seems to come in vast quantities) is there an alternative solution?