Tiling a floating floor, How would you go about it

[peckers]

Hi guys and girls, I have been to look at two bathroom floors today that have been previously tiled.
The floors are floating floors and they consist of tiles laid with single part flexible adhesive onto 18mm chipboard onto polystyrene panels at 75mm thick which is then onto dpm laid on concrete.
And yes you guessed it, it has all cracked!!!
Now the customer wants it re tiling!

Now this is how I am going to go about it, if you have any better ideas on how to do this then please chuck your comments or critisisums in please!!

1. Remove bathroom suites totally
2. lift tiles and chipboard flooring and polystyrene
3. I am going to cut the chipboard leaving 1" of the original protruding from under the skirting,skirting is to stay as is.
4. fix down 3x2 timbers on top of the dpm to concrete floor at 300mm centres and put in noggings making sure this is all level and solid.
5. I am going to double up on the 3x2 around edge of skirting board allowing it to go under the 1" of original chipboard that is staying.
6. Reinstate the polystyrene insulation.
7. Prime the back and edges,Then fix down 18mm wbp ply(marine grade) to the 3x2
8. Give the face of the ply a coat of pva(not really) ACRYLIC PRIMER.
9. Then tile the floor with 300x300mm tiles useing bal fast flex adhesive and flexible grout
10. Then seal the grout and silicone against skirying board
11. Reinstate bathroom suite.

Right then i think thats it so fire away any comments, suggestions, critisisums welcome

[Dave]

Bal don't recommend sealing the face side of the ply....and as long as you can get in solid and not puncture the DPM, then go for it.

[grumpygrouter]

Hmmm Fast flex....great fun!!!!!!!!!

[brian c]

floating floors aswell...there may be trouble ahead!

[enduro]

I would use Velcro to stick the tiles down and pour jelly into the grout joints ( I think Robinsons do various colours but i quite like raspberry) let it set then bobs your uncle job done,

[biffa]

i would suggest using ditra and single part flex adhesive as opposed to fast flex.

[smurf21]

How will you fix the 3x2 without puncturing the dpm?

why not put down a 75mm screed floor let dry hard and lay using green screed addy?