Yes, it is common practice to install a countertop directly on top of cabinets. In fact, this is the standard method of installation for most kitchen and bathroom countertops. The cabinets provide the necessary support and base for the countertop to rest on.
During the installation process, the cabinets are leveled and secured to the wall. Then, the countertop material, such as granite, quartz, laminate, or solid surface, is cut and shaped to fit the dimensions of the cabinets. The countertop is typically secured to the cabinets using adhesive, screws, or other appropriate fasteners.
It's important to ensure that the cabinets are structurally sound and capable of supporting the weight of the countertop material. If you're planning to install a heavy or particularly dense countertop material, it's recommended to consult with a professional installer or contractor to ensure the cabinets are properly reinforced if necessary.
Overall, installing a countertop directly on top of cabinets is a standard and widely practiced method that provides a stable and functional surface for your kitchen or bathroom.