1950s house i grew up in... half a century later.. the water heater leaked... and the floor led the water straight to the drain...

where would have it gone if the floor was level??? .. the entire basement would have been wet ...

ken

Self leveler is brittle. Great under a finished material like tile when properly bonded but will fail quickly if it’s the finished surface. IMHO throw down some horse mats over the painted concrete and call it a day. You would need to get off a good amount of the paint, then use a bonding primer. Especially deep areas have to have wire mesh added.

I should add that the concrete floor is not intended to be the finished surface - I'm going to put rolled rubber gym flooring on top of it (horse stall mats of course are a classic for home gyms, actually used them in a previous home...but with my new house I'm going a little fancier).

Agree that I don’t think I’d mess with the floor. If you’re worried about covering the gaps on the wall, go higher with your baseboard moulding. Surely it’s not that big of a gap. Higher baseboards look better anyway. You may have to scribe them if the floor is too uneven (or use shoe moulding). In our basement we have plain 5 1/2” cedar as baseboard (painted).

Then yes I think it will work,, but I would fully expect when the time comes and you pull up the horse mats or whatever that the self leveler is cracked and or delaminated.

As for removing the paint, probably grinding is 'easiest' since it doesn't have to be pretty. Home depot rents concrete grinders which are like floor sanders on steroids. If you get 80% of the paint removed I think you will be fine.

ken_adrian Adrian MI cold Z5 - the floor is not sloped in a way that that goes towards any sort of drainage system. If anything the water would just pool in the middle of the floor.Susie . - I'm more so worried that if I have baseboard going straight across, I wouldn't be able to get it to sit on the bottom of the floor right. On one wall the floor sort of "humps" in the middle. Maybe it would be easier to explain with a picture...ill try to take one later. Agree that I prefer higher baseboards as well HALLET & Co. - thank you for the advice...I'm leaning toward not going directly on the painted concrete, so I don't have to deal with the cracking later...although with the rubber flooring on top I may never notice... Would I actually be able to use a concrete grinder to level the floor instead of using self leveler? It's possible the floor isn't as bad as I think...maybe if I just grind a few spots down it will be ok...

That’s why you would need to scribe the baseboards - pro finish carpenters do it for uneven floors regularly

If, you are using 3/4" gym mats. Just hang you baseboards 3/8" off the slab, then install the mats tight to it.

There are surface primers to bond the self leveling compound to various floor surfaces. Below is just one available at my nearby box store. It looks like this primer is not to be used on 'painted surfaces'. I like the idea above of grinding the surface paint, then I would apply a primer.

https://www.menards.com/main/flooring-rugs/tile-stone/tile-installation-maintenance/tile-waterproofing-surface-prep-systems/tec-reg-multipurpose-primer-560-1-gal/7050085013/p-5239772154384327-c-6590.htm?exp=false

Suggestion - to mix a large amount of leveling compound at once, I looked on-line for used 55 gallon drums in my area. I went to one such supplier and it turned out to be a car wash! They didn't want to fool with money and receipts; they just gave me an empty 55 gal plastic drum as a freebie (they retrieved it from the dumpster!). I cut the top off and had a large container to work with.

Need to grind paint off as suggested. As far as mixing in big batches, the containers becomes a challenge to move unless you are mixing in place. I usually mix two bags at a time. There is plenty of working time.