I am in the process of installing base cabinets in my kitchen. From what I have read online from articles such as this, it sounds as if base cabinets only need to be fastened to each other and the wall, not the floor.
This sounds reasonable, except that my kitchen floor has a considerable amount of runout (1-1/4" from highest point to lowest point, on opposite ends of a 11'x12' room). In this scenario, the cabinets in the low spots would be floating if only secured to the wall. It is my plan to make some custom blocking/shims to bring these cabinets level and to the proper height, but it doesn't quite seem sufficient just to have these blocks floating between the floor and the cabinet.
Is there a standard practice for this scenario? My thought was to at a minimum secure the blocks/shims to the floor with fasteners or construction adhesive. However, cabinet to floor I don't have many options at all due to the construction of the cabinet. It's made from 1/2" plywood and the floor of the cabinet is ~6" from the actual ground it rests on, so I would have to make some sort of blocking that goes behind the sidewalls to screw in from the side or blocking that reached the bottom of the cabinet to secure downwards from the cabinet floor.
Also, for other cabinets were only small, wedge type shims are going to be used, do you just break them off in place and leave as-is? Seems like over time these could walk out with only a thin 1/2" plywood sheet resting on top of them.
Edit: After looking at some more tutorials, it seems this one suggests that you run screws into the toe-kick at a downward angle to sort of toe nail it in place. Seems a little tough to do through 1/2" plywood and not split it, but if it's only to hold the shims in place that bear the weight of the cabinet that make sense. I'll just need to use longer screws on the cabinets that are shimmed more.