Midrexâs primary business is direct reduction ironmaking. We build DRI plants that work day in and day out, year after. year to provide value for our clients so that they can make. the most of their investment and maximize their profits for. years to come. The MIDREXÂ® Process 2. The MIDREXÂ® Process.
Quick Answer. The maximum interior height of an entry door threshold is 1/2 inch, and up to 3/4 inch on exterior siding doors where it is essential to keep water out, as stated by the United States Access Board. These height limits improve wheelchair access to buildings.
Total width for rough opening is 51&1/2. Height will be determined by the height of the doors and the desired clearance between the bottom of the doors and the floor. Many bifold doors are designed to fit 80 high openings and allow a half inch clearance at the top and 1&1/2 to 2 at the bottom. That means the top rough header should be at 81 to 82&1/2.