I am converting a corner of a garage into a utility room. The owner intends fitting laminate flooring after I have installed the worktop and units. Rather than sit the units on the concrete floor and have the guy cut the flooring to fit round them I intend leaving a gap so he can fit his flooring underneath. The thing is; how much of a gap should I leave? Does laminate flooring and underlay come in standard thicknesses? Should I suggest adjustable feet on the units?