A method of constructing a water-resistant corner for a tent or other fabric structure, and the corner formed therefrom. A protective panel may be laid over a flooring material sheet, and the sheet and the protective panel are folded into a corner. The formed corner may then be turned inside out, so that the protective panel is located on the outside of the newly-formed corner. The protective panel thereby covers the outermost corner of the flooring, and the seam formed at that corner. An interior waterproof layer, such as a waterproof sealing tape, may be attached on the inside of the inverted corner to act as a further moisture barrier.