I have a house from '66 with a cast vault to the upper floor. It looks like some kind of structural concrete, then another concrete, and finally, they've leveled the floor with something very fine mortar/plaster/concrete/cement/whatever. The point is that this last completely flat and smooth layer is laid after the interior walls are built, which means that when I tore down some interior walls, the floor is a bit uneven where the wall stood. This last layer is between 2-10 mm thick depending on the concrete underneath. It's quite soft.
My question is: What should I use to fill the unevenness under the old wall? Plaster mortar, cement? Any tips on the procedure, or is it just a matter of grabbing a trowel and getting to work?
My question is: What should I use to fill the unevenness under the old wall? Plaster mortar, cement? Any tips on the procedure, or is it just a matter of grabbing a trowel and getting to work?
You should use floor filler. Check with your building supplier to see what they have. If the old filler is very bad, you should replace it as well. You can check if it's bad by taking the handle of a broom and tapping on the floor. If it sounds like it's loose, it might sound a bit hollow, then it's bad.
If it turns out that large areas are bad, you might need to consider self-leveling compound. I probably wouldn't attempt to do it myself. However, if you want to, it's important to seal all penetrations in the floor (don't forget the areas close to the walls as well). Otherwise, you'll have self-leveling compound all over the ground floor as well.
If it turns out that large areas are bad, you might need to consider self-leveling compound. I probably wouldn't attempt to do it myself. However, if you want to, it's important to seal all penetrations in the floor (don't forget the areas close to the walls as well). Otherwise, you'll have self-leveling compound all over the ground floor as well.
There we go, now that job is done... Well, almost anyway. As I suspected, the old putty or whatever it was was in poor condition in certain places. It had detached from the substrate and it seemed like the putty itself wasn't properly mixed since under the surface it was almost as loose as gravel. Knocked off all the loose stuff, primed, and applied new putty. Now I just need to buy a finer putty for really thin layers since it's needed in a few spots.
Thanks for the help!
Thanks for the help!