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.
Interior Doors. The height for all passage doors must be a minimum of 80 inches and the standard width sizes for interior doors are 24â, 28â, 30â, 32â and 36â. The minimum recommended door width to allow persons with disabilitiesâ to pass through is 36 inches.