Dear all, I live in an apartment in Greece. At the moment my floor is covered with tiles, but due to bad construction (all the apartments in mu building have the same issue) the tiles are now floating. The building was made in 1995. Typical concrete 4 floor apartment building. Now I want to replace the tiles with laminate, and fix the subfloor so it won't happen again. I removed one tile, and I am attaching the pictures. The subfloor is this "sand like", spongy grey stuff that is easily scraped. Although idk what it is exactly, and also how to deal with it. I should be that fragile? Needs hardening? Needs covering? Removal? And after that obviously it needs to become perfectly flat in order to receive the laminate. Please help me!
Looks like the sand and cement substrate was mixed wrong and there’s way too much cement in the mix to me! The correct way to go about it would be to use a case hardener to strengthen the subfloor before priming and screeding BUT if you are only putting a floating floor (laminate) down then this won’t put any tension on the subfloor. In other words.... there’s no need to go to such expensive. Just lay over the subfloor IF ITS FLAT! If you wanted to lay LVT then you would have to case harden
