My workshop floor is all wibbly-wobbly where it was originally tamped (bit like a really heavy brushed finish). There's also a bit of a fall off to the rear corners. The finished surface will probably be PVC floor tiles so I need to minimally fill the "troughs" in the ripples to prevent knackering the tiles. I'm a bit torn - I was thinking to either use a dry sand/cement mix and filling to the top of the peaks but I'm concerned that because the underside of the PVC tiles is hollow that the tiles could sink over time. Option 2 is self levelling - I have no experience of it. Is it really as simple as mixing it up, pouring it, shoving it about with a spiked roller then presto, it's smooth and flat? YouTube/Google are contradictory - some say pour it and it'll flatten out whereas others say you need to trowel it off or you end up with mounds. Any info or experience would be great! Cheers, Fro