What is Slick Mix™ polish-able self leveling concrete overlay? Slick Mix ™ polish-able self leveling concrete overlay is used mainly as an self leveling compound floor leveler. It is the newest formulation of self leveling compounds with extended flow and heal times and higher compression strength. This product was engineered to offer many solutions in the flooring industry. It may be used as a traditional flooring underlayment. This is to smooth out sub-floors to make instal