Tiling on a floating chipboard floor - Tile Advice

[rtuzuk2]

Hi,
I've read posts regards tiling on a floating chipboard floor, i have approx 30mm of polystyrene, with 20mm of chipboard on top. There is damp proof sheet under the polystyrene then concrete under that. There is a small amount of deflection when you walk over the floor.

Is there anyway to screw the chipboard into the concrete floor ? Or is the only alternative to rip out the existing flooring ??

 

[DHTiling]

If you screwed it down then you would puncture the DPM, and deflection on floating floors is part and parcel of them...If you have the option to screed then i would..but you will probably lose the insulation as you need depth for the screed..but not the end of the world...