TLDR question: How thinly can I feather regular concrete to roughly level my basement floor as a base for self-leveling compound?
Background: I am in the process of re-finishing my basement after addressing the issues we discovered with the PO’s “finished” basement (They slapped bat insulation and paneling directly against the unsealed concrete walls, and over live electrical outlets). Waterproofing, drainage, etc has been addressed.
The basement (23’x17’) has an elevation change of 3.5” from one corner to the other. This is a combination of initial construction slope towards the basement drain (removed during waterproofing) and a more pronounced slope around the drain where some prior plumbing work was done (we assume).
This obviously exceeds the Max thickness for self leveling compound. However, all of the regular concrete lists a Minimum thickness of 2”.
Question: Can I pour a base of regular concrete, about 3” at the thickest, to fill in the majority of the low area and feathering out from there? Then using self leveling compound as a top coat over that?
Also, are there any specific preparations or factors to be considered when layering pours like this?