Novice here, hopefully someone can help me. I'll shortly be re-tiling the kitchen floor. The existing floor is quarry tiles, all secure, no damp, pretty uneven, but not bad. I was going to use a self leveling compound over the top and selectively remove the most uneven quarry tiles (only 2 or 3 tiles). However I have an area of concern by the back door. The back door sits on a 30cm wide concrete sill that brings a little moisture/damp into the kitchen. The damp doesn't spread beyond this concrete sill, but I will be tiling over this sill as it protrudes into the kitchen approx. 20cm. The sill is at the same level as the existing quarry tiles.
Can I just paint the concrete sill with a damp proof paint (black jack paint?), and then use self leveling compound over this paint?