A floor assembly is provided. The floor assembly is configured to form or be positioned on a floor of an enclosed space. The floor assembly includes a grid, a pan, and a surround member. The grid has an array of openings configured to allow passage of liquid. The pan is disposed beneath the grid and defines a cavity. The pan includes a pan floor and a frame. The frame is disposed laterally outward of the pan floor and supports the grid. The surround member is supported by the frame. The surround member is disposed laterally outward of the grid, and the surround member and grid do not overlap.