Thanks for the feedback,that's what this is all about.Tips for floor preparation? First of all,if the floor itself is as you say "squeaking",this can be remedied by screwing the boards down.Maybe they were nailed down when the house was constructed,but screws should sort that out.Be careful not to screw through any pipes or cables that might below the floor.When you have tightened the floor boards up,and you decide to go ahead and tile the floor,it is always advisable to cover the floor area to be tiled, with 9mm(minimum) WBP plywood sheets or even 12mm.This would be screwed down at 6" centres all over the boards,so a lot of screws,and stagger the joints,again think of pipes and cables.You are now ready for tiling.After setting out,fix the tiles with FLEXIBLE TILE ADHESIVE (powder mix) for TIMBER FLOORS,and a flexible grout (powder mix) for timber floors.It is a good tip to cut,number and dry lay a few tiles in advance,and then mix up the adhesive and fix the ones that are ready,and so on.The adhesive once mixed will set hard quickly,(45 mins or so)so don't mix too much at once,follow the manufacturers instructions on the bag.Clean everything after each mix, buckets,tools etc.Use plastic spacers or bits of card to keep even spaces.Sorry i've gone on a bit.Good luck.
Roughcaster.