The door gap bottom is the space between the bottom of a door and the floor it closes against. This gap can vary in width based on the type of door, flooring materials, and architectural design. Ideally, it should allow for smooth operability of the door while preventing obstruction from carpets or rugs. Manufacturers often specify an optimal gap, usually around 1/2 inch to 3/4 inch, yet acceptable dimensions may vary depending on specific circumstances.