Hinge positioning is determined by the size, weight and construction of the door and its intended use. The top and bottom hinges are easy – around 250mm from the top and bottom of the door. The most common position for the third hinge is in the middle, this is a good position where the loading is normal. The middle hinge will also stop a door from warping in a humid environment. Where a door is heavier, wider or has a door closer, then the middle hinge should be moved up to about 200mm below the top hinge. When four hinges are used due to extra weight, height, width, abuse level, the hinges can be either equally positioned or set as two pairs at the top and bottom separated by about 200mm.