Q: Can I install new kitchen units on top of a floating floor? It seems like it would be easier to lay the flooring first and not have to cut it to fit against the kickboard or cover up the gap with scotia moulding.

It might be easier, but it wouldn't be better. A floating timber or laminate floor needs freedom to expand and contract with seasonal changes in humidity, and it cannot do that with heavy kitchen units resting on top of it.

That is not the only problem: you would have a tough time cutting out the sections extending beneath the units if you ever wanted to replace the flooring; you would be spending money on flooring you will never see; and you run the risk of scratching your new floor if you install the units after it is in place. These are all good reasons to lay a kitchen floor after the base units are fitted.

Installing Flooring First

If your units have removable plinths (kickboards), consider taking them off so you can run the flooring slightly underneath the base units. If the kickboard is fixed, plan to install the flooring up to within 12 mm (½ inch) of the kickboard—this gap can then be hidden during the finishing step.

However, if you have no choice but to install the flooring first, here is a method to avoid these issues:

Undercut Trim and Architraves: Before installing the flooring, check for any vertical trim—such as door architraves or door stops—that needs to be cut back to allow the new floor to slide beneath it. Use a scrap piece of your flooring material alongside a piece of your underlay as a height gauge. Lay them flat against the trim, and use a flexible flush-cut saw to trim the wood flush.

Mark and Fit Filler Strips: Put all the base units in position, then mark a line on the subfloor corresponding to the front edge of the kickboard. Remove the units and screw a plywood filler strip to the subfloor about 12 mm (½ inch) inside the line, where it will sit hidden underneath the units. This piece should be at least 50 mm (2 inches) wide and about 3 mm (⅛ inch) thicker than the total thickness of your flooring and underlay combined (including any vapour barrier). Screw a second strip of the same thickness to the floor adjacent to the back wall.

Lay Floor and Reinstall Units: Install your new flooring, keeping it about 6 mm (¼ inch) away from the front filler strip to allow for expansion. Finally, seat the base units on top of both plywood filler strips and reattach the kickboards. The flooring will now be able to expand and contract freely beneath the kickboard without leaving a visible gap.

Top Tip: When installing a floating floor, always pin or nail any scotia moulding or quadrant trim to the wall or skirting board—never directly to the flooring itself. This ensures the floor can move freely underneath as temperature and humidity fluctuate in the kitchen.