When replacing both the lower kitchen cabinets and the flooring, the general practice is to install the flooring first and then place the cabinets on top of it. The flooring should extend under the cabinets, all the way to the wall, and not stop at the cabinet's edges.
Here's why it's recommended to install the flooring before the cabinets:
Seamless Look: Installing the flooring under the cabinets creates a more cohesive and seamless appearance. The cabinets will sit directly on the flooring, giving a polished look to your kitchen.
Ease of Installation: It's typically easier to install the flooring without the cabinets in place. This way, you can cover the entire kitchen floor without any obstructions, making the installation process smoother.
Stability and Leveling: Placing the cabinets on top of the flooring provides stability and helps level the cabinets. This is important for ensuring that your cabinets are properly aligned and function well.
Future Flexibility: If you decide to change your kitchen layout in the future or replace the cabinets again, having the flooring extend under the cabinets allows for more flexibility in design changes.
However, there are some exceptions to this rule. In certain situations, such as using specific types of flooring that are extremely thick or difficult to cut around cabinets (e.g., thick stone tiles or concrete), it might be more practical to install the flooring up to the cabinets' edges. In such cases, the gap between the flooring and the cabinets can be concealed with base molding or quarter round trim.
If you're unsure about the best approach for your specific kitchen renovation, it's always a good idea to consult with a professional contractor or flooring installer. They can assess your kitchen's unique characteristics and guide you on the best course of action to achieve a beautiful and functional kitchen space.