Walls built on floating floor now damaged by leak

[oona]

Wooden floor has been pulled up as was so damaged but i am now left with just concrete (batons were removed too) however the walls are now hanging from the ceiling. There is a 5cm gap underneath. Can i stuff something underneath them to support them and then put an engineered floor separately in both rooms?

 

[noseall]

Yes.

Skew fix a length timber to the floor with a strip of dpc in between, i.e. dpc on the concrete then timber. You can then make up the difference with another solid length and then 10-15mm packers.

You may need a few long (150mm) screws just to tie it all together and a decent impact driver.