1960s property with thermoplastic floor tiles and no DPC


New Member
I've a renovation where most of the property still has the 1960s thermoplastic floor tiles. I've had a flooring company tell me they are effectively the DPC and this seems to track. The tiles were removed from the kitchen by a previous owner, there was damp under the cupboards and part of the concrete is crumbling and wet. Where a breeze block cupboard had been built for the boiler a felt bitumen DPC layer had been put under the bottom row of brick.

This leads me to going forward. I've had several people say to fill the uneven bit of the floor with sand and cement, put a liquid DPC on top then self level to finish.

Separately, I've had a flooring company quote for:
Grinding existing concrete
First fill Self leveller
liquid DPC
Second fill Self leveller

This seems like double the work with the leveller and unless they're grinding quite far down is going to raise the floor level quite considerably. Another tradesman said that this would have to be the case as DPC/leveller layers should be 50mm.

I'd like to be able to go back to people a bit more prepared with knowledge so I can make sure I'm not being ripped off or ending up with something that is half a job and going to cause problems later.
Thanks for any advice.